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  • Springer  (125)
  • American Institute of Physics (AIP)
  • 2010-2014
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  • 1985-1989  (65)
  • 1970-1974  (60)
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  • 1
    Electronic Resource
    Electronic Resource
    Development of Xenopus laevis skin glands producing 5-hydroxytryptamine and caerulein (1989)
    Springer
    Cell & tissue research 258 (1989), S. 483-489 
    Details
    ISSN: 1432-0878
    Keywords: Development ; Skin glands ; Peptides ; Metamorphosis ; Xenopus laevis (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The granular glands in Xenopus laevis skin are known to contain large quantities of biogenic amines and bioactive peptides which closely resemble mammalian brain-gut peptides. We studied the development of glands producing 5-hydroxytryptamine (5-HT) and caerulein using immunohistochemistry, HPLC-fluorometric systems and RIA. The immunoreactivities of 5-HT and caerulein were first detected in the spherical gland rudiments in the stratum spongiosum at St. 58 (Nieuwkoop and Faber stage), or at the beginning of metamorphosis. Both immunoreactivities appeared in the same rudiment at the same time. Some of the gland rudiments have a small lumen filled with both immunoreactive materials at St. 58–59. During the rest of the metamorphic period, the glands grow in size, accumulating immunoreactive materials in the lumen. The concentrations of 5-HT and caerulein in the skin of tadpoles were below 1 ng per mg wet tissue at St. 58–59, increased as metamorphosis proceeded and reached 63 and 134 ng per mg wet tissue at St. 66, or at the end of metamorphosis, respectively. The amphibian granular glands where large quantities of biogenic amines and hormone-like peptides are rapidly synthesized may provide a useful model for the study of the development of amine- and peptide-producing cells including neurons and paraneurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218860
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  • 2
    Electronic Resource
    Electronic Resource
    An immunohistochemical study on the postnatal development of rat nasal-associated lymphoid tissue (NALT) (1989)
    Springer
    Cell & tissue research 256 (1989), S. 431-438 
    Details
    ISSN: 1432-0878
    Keywords: Mucosa ; Lymphoid tissue ; Nose ; Development ; Immunohistochemistry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This study concerns the development of nasal-associated lymphoid tissue in the rat, using immuno- and enzyme-histochemical staining techniques on cryostat sections. Nasal-associated lymphoid tissue is present at birth as a small accumulation of mainly T lymphocytes and non-lymphoid cells; B cells are rare. Distinct areas of T and B cells appear at 10 days after birth; by that time high endothelial venules are also observed. Intra-epithelial lymphocytes are present, most of them being T-helper cells. ED1+ macrophages are seen throughout the tissue. The proportion of ED1+cells does not change during ontogeny. ED2+cells (tissue macrophages) are present predominantly at the border between the lymphoid tissue and the surrounding connective tissue, in all age-groups. ED3+mononuclear cells are scattered throughout the nasal-associated lymphoid tissue of young animals. Later on, the ED3+ cells migrate into the border-area between lymphoid and connective tissue. Ia+ non-lymphoid cells in the nasal lymphoid tissue increase in number during ontogeny. Only a few of them show acid phosphatase activity, indicating that the proportion of classical scavenger macrophages is low. Some of them may be antigen presenting (dendritic) cells. Ia+ dendritic cells also occur between the epithelial cells. Moreover, some epithelial cells express the Ia marker.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218901
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  • 3
    Electronic Resource
    Electronic Resource
    Expression of α and β tropomyosin subunits during early myogenesis in somites and limb buds of chick embryos (1989)
    Springer
    Cell & tissue research 256 (1989), S. 631-634 
    Details
    ISSN: 1432-0878
    Keywords: Development ; Skeletal muscle ; Tropomyosin ; Somites ; Limb buds ; Chick embryo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The appearance of α and β subunits of skeletal tropomyosin in early myogenesis was studied histochemically using monoclonal antibody to α tropomyosin and affinity-purified polyclonal antibody to β tropomyosin. In muscle cells, in both somites and limb buds, the α and β subunits are simultaneously expressed and first appear in the somites at the 30–36 somites. The relatively greater amount of β than α tropomyosin found in early myogenesis is thus likely to result from a higher rate of β tropomyosin synthesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225613
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  • 4
    Electronic Resource
    Electronic Resource
    Distribution and frequency of neuro-epithelial bodies in post-natal rabbit lung: Quantitative study with monoclonal antibody against serotonin (1989)
    Springer
    Cell & tissue research 255 (1989), S. 353-362 
    Details
    ISSN: 1432-0878
    Keywords: Development ; Intrapulmonary chemoreceptor ; Immunocytochemistry ; Morphometry ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution, frequency and size of neuroepithelial bodies (NEB) were studied in lungs of rabbits during different stages of development (27-day fetus, newborn, 6, 11, 21, 28 and 56 days postnatally). NEB were visualized by immunostaining with monoclonal antibody against serotonin. Detailed quantitiation of NEB was performed by use of camera lucida drawings of immunostained serial sections from the same anatomical region, i.e. the lower lobe of the left lung. The total number of NEB was counted and expressed per epithelial length of airway, surface area and volume. The size of NEB defined as surface area as well as the position of NEB in relation to the airway bifurcations was assessed in airways of different sizes. The overall number and size of NEB were found to increase during the immediate perinatal period followed by a sharp decline at 56 days of age. The number of NEB peaked at 6 days postnatally (mean 175.5 NEB/mm3 of airway epithelium) and declined significantly (3.0 NEB/mm3) at 56 days of postnatal age. The size of NEB reached its maximum at 11 days (mean surface area 659.54 μm2, with the largest NEB measuring 1839.98 μm2). By 56 days of age, NEB became significantly smaller (mean surface area 177.29 μm2) consisting of small clusters of cells situated deep within the airway epithelium. At all ages, about half of all NEB (mean 47.6%) were localized within the small peripheral airways with up to 63.9% located at airway bifurcations. These findings indicate that the “functional activity” of NEB may be confined predominantly to the perinatal period. The postulated functions of NEB include those of intrapulmonary hypoxia-sensitive chemoreceptors and/or endocrine-paracrine activity in the lung. Such function(s) may be important during adaptation to extrauterine life as well as for growth and development of the lung.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224118
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  • 5
    Electronic Resource
    Electronic Resource
    Plasma membrane proteins associated with undifferentiated and embryonicDaucus carota tissue (1989)
    Springer
    Protoplasma 150 (1989), S. 139-149 
    Details
    ISSN: 1615-6102
    Keywords: Biotinylation ; Daucus carota ; Development ; Embryogenesis ; Plasma membrane, SDS-PAGE
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Membranes and membrane proteins from undifferentiated cells and torpedo-stage embryos were compared. A comparison of marker enzyme profiles on linear sucrose gradients showed that the membrane vesicles obtained from 14-day-old embryos were consistently less dense than those obtained from undifferentiated carrot cells. The density of the endoplasmic reticulum, for instance, was 1.10g/cm3 in embryos and 1.12g/cm2 in undifferentiated cells. Proteins and glycoproteins from endoplasmic reticulum-, Golgi apparatus-, and plasma membrane-enriched fractions were compared from undifferentiated carrot cells with 14-day-old embryos by 2D SDS-PAGE. When these two tissues were compared, extensive qualitative and quantitative changes in the steady-state endomembrane and plasma membrane proteins were observed. The plasma membrane was examined further by labeling the plasma membrane proteins with sulfosuccinimidylbiotin. Using this specific label, plasma membrane proteins of 54 kD, 41 kD, 16 kD, and 15 kD were found to be uniquely associated with the embryonic state. Conversely, a 70 kD protein and a 45 kD glycoprotein were found to be associated with only undifferentiated cells. These results demonstrate that proteins of the plasma membrane exhibit distinct changes as a result of somatic embryogenesis in carrot.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01403670
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  • 6
    Electronic Resource
    Electronic Resource
    Cyclic development of contact behavior in apes and humans (1989)
    Springer
    Primates 30 (1989), S. 269-279 
    Details
    ISSN: 0032-8332
    Keywords: Development ; Gorillas ; Orangutans ; Chimpanzees ; Apes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Nursing and mother-infant distance were observed in three orangutans, two gorillas, one chimpanzee and four humans. All four species showed periods of a recurrence of greater time spent nursing and in contact with the mother. The initial regressive or reattachment period occurred similarly in all four species at between 6–12 months of age. An orangutan observed for two years showed a second period at 19–21 months. Other studies of weight gain in the three ape species coincidently peaked at the same time. When estimated peaks of individuals of each species were summed, the resulting graphs showed a differentiation of species rates of development. Gorillas developed most rapidly, orangutans developed most slowly, while chimpanzees and humans developed within the middle range.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02381314
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  • 7
    Electronic Resource
    Electronic Resource
    A longitudinal investigation of gestural communication in young chimpanzees (1989)
    Springer
    Primates 30 (1989), S. 35-50 
    Details
    ISSN: 0032-8332
    Keywords: Chimpanzees ; Communication ; Development ; Social learning ; Culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A longitudinal study of chimpanzee gestural communication is reported. Subjects were seven 5- to 8-year-old members of a semi-natural group at the Yerkes Field Station. These were the same individuals observed byTomasello et al. (1985) four years previously. Nearly identical operational definitions and observational procedures were used in the two studies. Longitudinal comparisons between the two observation periods revealed that the development of chimpanzee gestural communication is best characterized as a series of ontogenetic adaptations: as particular social functions (e.g., nursing, playing, grooming, etc.) arise, decline, or change, gestural communication follows suit. Most gestures seem to be conventionalized by individuals in direct social interaction with conspecifics. Some gestures may be learned by “second-person imitation”—an individual copying a behavior directed to it by another individual. No evidence was found for “third-person imitation”—an individual copying a gesture used between two other individuals. Implications for the concept of chimpanzee “culture” are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02381209
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  • 8
    Electronic Resource
    Electronic Resource
    Endogenous 24-hour cycle of core temperature and oxygen consumption in week-old Zucker rat pups (1989)
    Springer
    Journal of comparative physiology 159 (1989), S. 569-575 
    Details
    ISSN: 1432-136X
    Keywords: Artificial rearing ; Circadian ; Development ; Newborn ; Thermoregulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Experiments were designed to test whether or not the 24-h core temperature fluctuations in week-old rat pups are of endogenous origin. Lean (Fa/-) Zucker rat pups born on the same day to mothers maintained in two different colonies with light/dark cycles 12 h out of phase with each other were mother-reared through the first 3–4 days of life and then artificially reared simultaneously in constant dim light. Continuous, automatic measurement of core temperature and oxygen consumption during artificial rearing showed clear 24-h rhythms in 5- to 8-day-old pups. Each rhythm reached a daily minimum at a time corresponding to the beginning of the light period in the colony of origin. The amplitude of these rhythms did not diminish during artificial rearing, nor did the phase difference between the rhythms of pups originating in the two colonies systematically change. The persistent 12-h phase differences between these two groups of pups prove that the observed rhythms are not caused by exogenous stimuli. We conclude that the rat pup possesses an endogenous time-keeping mechanism that permits the expression of overt rhythmicity at the age of 1 week.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00694381
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  • 9
    Electronic Resource
    Electronic Resource
    The reinforcement-extinction process of selector gene activity: a positive feed-back loop and cell-cell interactions in Ultrabithorax patterning (1988)
    Springer
    Development genes and evolution 197 (1988), S. 424-434 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Ultrabithorax ; Development ; Regulation ; Protein distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Most viable alleles of homeotic genes cause partial transformations within given lineages in a topographically specific fashion. We study this phenomenon as a way to understand the normal mechanisms involved in the spatial regulation of homeotic gene expression. To this end we have investigated the distribution of Ultrabithorax (Ubx) proteins in imaginai discs mutant for hypomorphic and neomorphic alleles of Ubx and alleles of trans-acting genes. We find that the morphological discontinuities observed in the adult transformations are caused by corresponding new patterns of the Ubx proteins in the imaginai anlagen. These novel patterns of Ubx proteins are understood as a consequence of a process of reinforcement-extinction of Ubx expression. The evidence suggesting that this process results from a positive feed-back loop and cell-cell interactions is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00398994
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  • 10
    Electronic Resource
    Electronic Resource
    The relationship among egg size, density and food level on larval development in the wood frog (Rana sylvatica) (1988)
    Springer
    Oecologia 75 (1988), S. 67-72 
    Details
    ISSN: 1432-1939
    Keywords: Rana sylvatica ; Egg size ; Development ; Density ; Food level
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Although inter- and intraspecific variation in egg size among amphibians has been well documented, the relationship between egg size and fitness remains unclear. Recent attempts to correlate egg size intraspecifically with larval developmental patterns have been equivocal. In this study the development of larvae derived from large eggs and small eggs, from a single population in Maryland were compared under a range of food levels and larval population densities. Both food level and density had significant effects on the length of the larval period and size at metamorphosis. However, the response among larvae derived from different egg sizes was not additive. At low densities and high food levels, larvae from small eggs had longer larval periods and a larger size at metamorphosis than larvae derived from large eggs. In contrast, at high densities larvae from small eggs had longer developmental periods but were smaller at metamorphosis than larvae from large eggs. In addition, larvae from small eggs were more sensitive to density irrespective of food level. These results suggest that optimal egg size is correlated with environmental factors, which may explain the maintenance of both geographic and within population variation in egg size commonly observed in amphibians.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00378815
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  • 11
    Electronic Resource
    Electronic Resource
    Nerve growth factor-inducible, large external (NILE) glycoprotein in developing rat cerebral cells in culture (1988)
    Springer
    Cell & tissue research 252 (1988), S. 181-190 
    Details
    ISSN: 1432-0878
    Keywords: Embryonic rat brain ; Cell culture ; Development ; NILE-glycoprotein ; Neurons ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Fetal rat cerebral cells underwent neuronal differentiation in culture. This process was accompanied by distinct changes in the cellular glycoprotein pattern. The incorporation of [3H]-fucose into two proteins of apparent molecular weights of 30000 and 60000 daltons was significantly decreased and specific developmental changes were observed in a group of glycoproteins with high molecular weights (150000–250000 dalton). By means of indirect immunoprecipitation one of them was identified as NILE gp (nerve growth factor-inducible large external) glycoprotein (200000 dalton), a marker of central and peripheral neurons. Its developmental expression on neurons of dissociated rat cerebral cultures was studied using the indirect immunofluorescence technique and compared to the fluorescent-labeling pattern of other neuronal markers. Neurons expressing NILE gp were detected as early as after one day in culture. No preferential staining of neuntes versus cell bodies was observed. Two classes of NILE gp-positive cells were identified. One group consisted of a rounded cell-type, whereas the other group was represented by larger, more spindle-shaped neurons with a limited number of neuritic processes. In most cases one of these neuritic processes was preferentially labeled. Astroglia cells, as identified by immunolabeling with antisera against the glial acidic fibrillary protein, were observed to develop and mature after the first week in culture. NILE-positive neurons were found to be positioned in close association with glial cell processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00213840
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  • 12
    Electronic Resource
    Electronic Resource
    Development of the esophageal muscles in embryos of the sea urchin Strongylocentrotus purpuratus (1988)
    Springer
    Cell & tissue research 252 (1988), S. 411-417 
    Details
    ISSN: 1432-0878
    Keywords: Myogenesis ; Sea urchin embryo ; Development ; Muscle ; Mesenchyme ; Strongylocentrotus purpuratus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Development of the esophageal muscles in embryonic sea urchins is described using light- and electron microscopy. The muscles develop from processes of about 14 cells of the coelomic epithelium that become immunore-active to anti-actin at about 60 h (12–14° C). Initially, eachmyoblast extends a single process with numerous fine filopodia around the esophagus. By 72 h the processes have reached the midline and fused with those from cells of the contralateral coelomic sac. Myoblasts begin to migrate out of the coelomic epithelium between 72 and 84 h. By 72 h the processes stain with the F-actin specific probe NBD-phallacidin. The contractile apparatus is not evident in transmission electron-microscopic preparations of embryos at 70 h, but by 84 h the contractile apparatus is present and the muscle cells are capable of contraction. Because the myoblasts migrate free of the coelomic epithelium and are situated on the blastocoelar side of the basal lamina, it is suggested that that they should be considered as a class of mesenchymal cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214384
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  • 13
    Electronic Resource
    Electronic Resource
    Distribution of peptide-immunoreactive nerves in the foetal and newborn guinea-pig caecum (1988)
    Springer
    Cell & tissue research 253 (1988), S. 105-114 
    Details
    ISSN: 1432-0878
    Keywords: Enteric nervous system ; Autonomic nervous system ; Development ; Vasoactive intestinal polypeptide ; Substance P ; [Met]enkephalin ; Somatostatin ; Guinea pig, Dunkin-Hartley
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of vasoactive intestinal polypeptide-, substance P-, [met]enkephalin- and somatostatin-like immunoreactive nerves was studied in the caecum from foetal guinea-pigs of 6–9 weeks gestation (i.e., approximately 1–4 weeks before birth) and 4–5-day-old guinea-pigs. Peptide-immunoreactive nerves were first detected in the myenteric and submucous plexuses and circular muscle layer at 6 weeks of gestation and in the mucosa at 7 weeks of gestation. The density of fibres in these layers increased during prenatal development until, by 9 weeks of gestation, their distribution resembled that seen in the postnatal animals. This distribution was similar to that described previously in adult animals. A different pattern of development was observed in the caecal taenia coli muscle. Peptide-immunoreactive fibres were not detected until 8 weeks of gestation in this tissue layer, and were then only sparsely distributed. A dramatic increase in the number of labelled fibres, however, occurred between 8 and 9 weeks of gestation. Further, vasoactive intestinal polypeptide- and substance P-immunoreactive fibres were more numerous in the taeniae coli of 9-week-old embryos than in those of postnatal animals. Thus, the guinea-pig enteric nervous system, which in many respects is well-developed at the time of birth, may still be undergoing developmental changes at this time.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221745
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  • 14
    Electronic Resource
    Electronic Resource
    Developmental study of neuropeptide Y-like immunoreactivity in the neurohypophysis and intermediate lobe of the rhesus monkey (Macaca mulatta) (1988)
    Springer
    Cell & tissue research 254 (1988), S. 499-509 
    Details
    ISSN: 1432-0878
    Keywords: Neuropeptide Y ; Immunohistochemistry ; Pituitary ; Development ; Aging ; Neurohypophysis ; Intermediate lobe ; Hypothalamo-hypophyseal portal vessels ; Neuroendocrine regulation ; Macaca mulatta (Primates)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The purpose of this study was to examine the development and distribution of neuropeptide Y-immunoreactive fibers in the neurohypophysis of the rhesus monkey (Macaca mulatta) throughout life and the relationship of these fibers to the hypothalamo-hypophyseal portal vasculature. In rhesus monkeys, which varied in age from fetal life to 34 years, neuropeptide Y-immunoreactive fibers were present at all ages examined. In adult monkeys, varicose neuropeptide Y-labeled fibers were concentrated in the upper infundibular stem in association with capillary loops of the portal vasculature and the long portal vessels. Other fibers travelled down the infundibular stem and were distributed at the junction of the lower infundibular stem and infundibular process in the vicinity of the short portal vessels. In the infundibular process, neuropeptide Y-immunoreactive fibers were concentrated along the border of the intermediate lobe. Other stained fibers were sparsely distributed in the infundibular process and were often associated with small vessels. Neuropeptide Y-immunoreactivity was also located in a few fibers and cells of the intermediate lobe. Very few labeled fibers were seen in the fetal neurohypophysis, but their number increased gradually during the first postnatal year. At two years of age, a high density of stained fibers was observed, especially in the infundibular process. The number of axons in the infundibular process was lower at 12 years and continued to decline until 34 years of age. Neuropeptide Y may modulate hormone release at these sites and may also be released directly into vessels in the infundibular process. The close association of neuropeptide Y-labeled fibers with capillaries of the portal vasculature strongly suggests that neuropeptide Y is released into the portal blood of monkeys throughout life and may influence hormone secretion from the anterior pituitary gland.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00226499
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  • 15
    Electronic Resource
    Electronic Resource
    Analysis of the expression of extensin and p33-related cell wall proteins in carrot and soybean (1988)
    Springer
    Molecular genetics and genomics 211 (1988), S. 393-399 
    Details
    ISSN: 1617-4623
    Keywords: Cell wall ; Wounding ; Proline-rich proteins ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have identified p33 as a cell wall protein in carrot storage roots that increases in the cell wall after wounding, using antibodies raised against a synthetic peptide derived from the p33 cDNA sequence. The mRNA encoding p33 increases markedly within 1 h after wounding in carrots, indicating that p33 may be involved in one of the early cellular responses to physical damage. In contrast with extensin, p33 mRNA does not accumulate in carrot roots in response to ethylene or in carrot suspension culture cells incubated in the presence of a crude endogenous elicitor fraction. These results indicate that the wound-induced signals responsible for the synthesis of p33 and extensin after wounding are different. Protein immunologically related to carrot p33 and RNA transcripts homologous to p33 cDNA sequences were detected in the apical hook of the soybean seedling indicating that a cell wall protein related to p33 is also synthesized during plant development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00425691
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  • 16
    Electronic Resource
    Electronic Resource
    Studies on α-D-mannosidase and ConA during jackbean development and germination (1988)
    Springer
    Protoplasma 144 (1988), S. 34-45 
    Details
    ISSN: 1615-6102
    Keywords: ConA, α-D-mannosidase ; Immunogold labelling ; Seed cotyledons ; Legumes ; Development ; Germination ; Membrane traffic ; Targeting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Changes in the level and activity of α-D-mannosidase and ConA have been followed during a time-course of development spanning seed formation, desiccation and germination. In parallel studies, immunogold labelling has enabled these changes to be placed within a structural context of the cotyledon parenchyma cells during protein body formation, dehydration and subsequent autolysis during germination. The results indicate that the exo-glycosidase and lectin accumulate in parallel during seed formation and are packaged within the same protein bodies. Several lines of evidence suggest that the function of both proteins is related to events that occur during seed development rather than germination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01320278
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  • 17
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    Electronic Resource
    The ontogeny and phylogenetic conservation of MAP 2 forms (1988)
    Springer
    Protoplasma 145 (1988), S. 195-199 
    Details
    ISSN: 1615-6102
    Keywords: Microtubule-associated proteins ; Development ; Rat ; Quail ; Xenopus laevis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In the adult rat brain, MAP 2 is a high-molecular weight protein that is highly concentrated in dendrites. Immunoblots of homogenates of developing rat brain have indicated that a low-molecular weight form of MAP 2, MAP 2 c, is transiently expressed as the brain is undergoing morphogenesis. Using MAP 2-specific monoclonal antibodies, we have demonstrated that the compartmentalization of high-molecular weight MAP 2 and the developmental regulation of MAP 2 are conserved in mammalian, avian, and amphibian brain. We have also determined the distribution of MAP 2 c in developing neuronal tissue. MAP 2 c appears before high-molecular weight MAP 2 in developing neurons, and in contrast to the dendrite-specific high-molecular weight forms of MAP 2, MAP 2 c is present in axons and glia. We have also shown that MAP 2 c is present in the adult rat retina, where it is concentrated in regenerative photosensitive cells. The transient expression of MAP 2 c in the developing brain of three species as well as in adult photosensitive cells suggests a role for this protein in neurite growth and plasticity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01349359
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  • 18
    Electronic Resource
    Electronic Resource
    Developmental changes of plasma alkaline phosphatase, calcium, and inorganic phosphorus in relation to the growth of bones in the Japanese macaque (Macaca fuscata) (1988)
    Springer
    Primates 29 (1988), S. 395-404 
    Details
    ISSN: 0032-8332
    Keywords: ALP ; Ca ; P ; Development ; Japanese macaque
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The plasma levels of alkaline phosphatase (ALP), calcium, and inorganic phosphorus in the Japanese macaque were measured during its growing period. The plasma ALP level within two days after birth was 818±186 IU/1, and the level showed a temporary peak at about 2 months of age (2747±763 IU/1). The ALP level formed a plateau from 1 to 3 years of age, then decreased again and reached finally an adult level (211±71 IU/1). Sex differences were observed twice during the animal's lifetime, from 6 to 9 months of age and from 3 to 7 years of age. On integration of this complicated curve, a correlation was observed with the development of the length of the bones. The plasma levels of calcium and inorganic phosphorus which were high within two days after birth, reached adult levels at 3 months and 5 years of age, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02380962
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  • 19
    Electronic Resource
    Electronic Resource
    Development of tool use in a macaque and a gorilla (1988)
    Springer
    Primates 29 (1988), S. 413-416 
    Details
    ISSN: 0032-8332
    Keywords: Tool use ; Sensorimotor intelligence ; Development ; Japanese macaque ; Gorilla
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The development of the capacity to use a stick as a tool was tested in a macaque (Macaca fuscata) and a gorilla (Gorilla gorilla gorilla) infants that had previously shown to be able to use strings and supports as dragging tools. Subjects were tested between 15 and 38 months of age. Different levels of competence between the subjects emerged over testing. The macaque developed a stereotyped strategy to cope with the problem, only getting random successes, whilst the gorilla developed a flexible strategy and revealed to be able to mentally represent the solution of the problem. In fact, when not successful using the stick, the gorilla thought out an alternative strategy, choosing and adapting a new object to use it as a tool.
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    URL: http://dx.doi.org/10.1007/BF02380964
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    Intrinsic variability in the frequency of embryonic diapauses of the annual fish Nothobranchius korthausae, regulated by light:dark cycle and temperature (1988)
    Springer
    Environmental biology of fishes 22 (1988), S. 211-224 
    Details
    ISSN: 1573-5133
    Keywords: Development ; Environmental factors ; Parental influence ; Survival strategy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The influence of the light:dark cycle and temperature on the embryonic development, especially diapause, of the annual fish Nothobranchius korthausae was investigated. The variability of the frequency of diapause II during constant L:D cycle and temperature, but at different times of the year, was also studied. In agreement with previous studies it appeared that diapause I does practically not occur in N. korthausae (and other Nothobranchius species), even under sub-optimal conditions which are known to induce diapause II and III. Only at very low temperatures, a first developmental arrest could be induced during the dispersed phase, as well as during the reaggregation phase. Diapause II and III can be induced more easily, by exposing the embryos to low (sub-optimal) temperatures and short light periods (or constant darkness). Both diapauses are inhibited or terminated at high temperature and long light periods (12L:12D). The occurrence of an indirect light:dark response via the adult fishes could not be demonstrated. At moderate temperatures and in constant darkness (or short light periods) considerable variability in diapause II-frequency was observed. This could be an intrinsic feature of annual fish development, constituting a strategy for better survival of the species.
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    URL: http://dx.doi.org/10.1007/BF00005382
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    The need for conservation and management of Philippine coral reefs (1988)
    Springer
    Environmental biology of fishes 23 (1988), S. 141-154 
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    ISSN: 1573-5133
    Keywords: Cyanide ; Diversity ; Development ; Ecology ; Environment ; Fisheries ; Pollution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The biological diversity and productivity of Philippine coral reefs are threatened by siltation, destructive fishing methods, coral and shell collecting and overfishing. Destructive fishing includes: the widespread, illegal use of explosives; poisons such as sodium cyanide; muro-ami and kayakas fishing; and trawling. The recent decline in catch rates threatens the livelihood of 700 000 near-shore subsistence fishermen who catch 55% of the total landings. The new government under Corazon Aquino wishes to protect the marine environment through the creation of a viable marine conservation management plan, enforcement of existing laws and through cooperation between government, non-government and international agencies to provide education and research. The Department of Agriculture, which has the authority for fisheries, has designated the International Marinelife Alliance as the lead non-government agency involved with fund raising, net-training and finding alternatives to destructive fishing methods.
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    URL: http://dx.doi.org/10.1007/BF00000745
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    Organization and unusual expression of histone genes in the sea starPisaster ochraceus (1987)
    Springer
    Journal of molecular evolution 25 (1987), S. 29-36 
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    ISSN: 1432-1432
    Keywords: Histone genes ; Echinoderms ; Maternal mRNA ; Development ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The organization and maternal expression of histone genes differ greatly between the two echinoderm classes represented by the sea stars and sea urchins. We have isolated and characterized a 5.3-kb genomic DNA fragment encoding core histone genes in the sea starPisaster ochraceus. The majority of histone genes are organized as tandem repeats of the 5.3-kb fragment, which is present in as many as 700 copies per haploid genome. The identity, precise location, and transcriptional polarity of individual core histone genes within the repeat were determined by DNA sequence analyses. The gene order in the sea star (H2B, H2A, H4, H3) is different from that in sea urchins (H2B, H3, H2A, H4). What is remarkable is the low level of maternal histone mRNA inP. ochraceus eggs relative to that in sea urchins. This observation supports a recent suggestion that major changes in mode of gene expression, rather than in gene organization or copy number, can be correlated with major events in echinoderm evolution.
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    URL: http://dx.doi.org/10.1007/BF02100038
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    Catecholamines induce metamorphosis in the hydrozoan Halocordyle disticha but not in Hydractinia echinata (1987)
    Springer
    Development genes and evolution 196 (1987), S. 381-384 
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    ISSN: 1432-041X
    Keywords: Metamorphosis ; Catecholamines ; Development ; Neurotransmitters ; Hydrozoa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Planula larvae of the marine hydroids Halocordyle disticha and Hydractinia echinata were treated with the catecholamines epinephrine, norepinephrine and dopamine, as well as with certain of their precursors and agonists. Norepinephrine, l-dopa, dopamine and the dopamine agonist ADTN at concentrations ranging from 0.1 to 0.001 mM induced metamorphosis within 24 h in Halocordyle disticha, with no observable morphogenetic abnormalities. Epinephrine, the adrenergic agonists phenylephrine, isoproterenol and methoxyamine, and the catecholamine precursors phenylalanine and tyrosine were found not to induce metamorphosis at the concentrations employed. None of the compounds was effective in inducing metamorphosis in Hydractinia echinata. A model is presented for neural control of metamorphosis in Halocordyle disticha
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    URL: http://dx.doi.org/10.1007/BF00375776
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    Net-building behaviour, tolerance and development of two caddisfly species from the river Rhine (Hydropsyche contubernalis and H. pellucidula) in relation to the oxygen content (1987)
    Springer
    Oecologia 73 (1987), S. 242-250 
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    ISSN: 1432-1939
    Keywords: Net-building behaviour ; Development ; O2-deficiency tolerance ; Hydropsyche ; River Rhine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Tolerance, growth and development of H. contubernalis and H. pellucidula were analyzed at different O2-concentrations to determine the species specific potency amplitude in relation to O2-concentration. In addition netbouilding behaviour was compared at different O2-concentrations and current velocities. Under anaerobic conditions slightly greater tolerance was observed in H. contubernalis than in H. pellucidula. But at a higher O2-concentration H. contubernalis showed a distinctly higher O2-deficiency tolerance than H. pellucidula in relation to net-building activity, growth and development. In addition, more than 50% of H. contubernalis instars built capture nets with regular meshes at an O2-saturation of only 30% (15°C). High growth rates were also found at 50% O2-saturation and more than half the larvae developed into imagos. In addition to diminished net-spinning activity the mean growth rate started to decrease at an O2-saturation of 70% to 38% and the development into an imago was not possible in H. pellucidula. Because H. contubernalis corresponds to a regulative type, being able to maintain a high level of netbuilding activity, growth rate and development over a wide range (50% to 100% O2-saturation). On the other hand H. pellucidula corresponds to a conform type, because physiological efficiency decreases rapidly with falling O2-concentration, so that development into an imago is no longer possible below 85% O2-saturation. Positive correlation between net-spinning activity and tested current velocity between 10 cm/s and 25 cm/s (15°C) was found in H. pellucidula. H. contubernalis showed no change in net-building activity, over this range of current velocity. H. contubernalis can be classified as an euryoecious species with a great potency amplitude in relation to O2-concentration and current velocity. The high tolerance to O2-deficiency conditions probably allowed the early recolonization of the Mittel-and Niederrhein when a distinct O2-deficit (mean 29%, max 56%) could still be measured. H. contubernalis can be considered a bioindicator of O2-deficiency situations. Undisturbed development of H. pellucidula in this section of the river requires a further improvement in O2-content.
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    URL: http://dx.doi.org/10.1007/BF00377514
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    Seed development and vivipary in Zea mays L. (1987)
    Springer
    Planta 171 (1987), S. 358-364 
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    ISSN: 1432-2048
    Keywords: Abscisic acid ; Development ; Seeds ; Vivipary ; Zea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Seed development was investigated in kernels of developing wild-type and viviparous (vp-1) Zea mays L. Embryos and endosperm of wild-type kernels began to dehydrate at approx. 35 d after pollination (DAP); viviparous embryos did not desiccate but accumulated fresh weight via coleoptile growth in the caryopses. Concentrations of endogenous abscisic acid (ABA) in the embryo were relatively high early in development, being approx. 150 ng·g-1 fresh weight at 20 DAP. The ABA content declined thereafter, falling to approx. 50 ng·g-1 at 30 DAP. Endosperm ABA content was always low, being less than 20 ng·g-1. There were no differences between wild-type and vp-1 tissues. Immature kernels did not germinate when removed from the ear until late in development. The ability to germinate was correlated with decreasing moisture content in the endosperm at the time of removal; premature drying of immature kernels resulted in greatly increased germination following imbibition. Excised embryos germinated precociously when removed from the endosperm as early as 25 DAP. Such germination could be prevented by treatment with 10-5 M ABA or by lowering the solute potential (Ψs) of the medium with 0.3 M mannitol. Treatment of excised embryos with ABA led to internal ABA concentrations comparable to those in embryos in which germination was inhibited in situ. Mannitol treatment did not have this effect, although water-deficit stress of excised embryos resulted in substantial ABA production. Germinated vp-1 embryos were less sensitive to growth inhibition by ABA or mannitol than germinating wild-type embryos. The vp-1 seedlings were not wilty and their transpiration rates were reduced in response to ABA or water shortage.
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    URL: http://dx.doi.org/10.1007/BF00398681
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    Embryonic somatic nerve destruction with β-bungarotoxin (1987)
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    Cell & tissue research 247 (1987), S. 41-50 
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    ISSN: 1432-0878
    Keywords: β-Bungarotoxin ; Peripheral nerve ; Development ; Regeneration ; Rat embryo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects and time course of a single injection of β-bungarotoxin into E14 rat embryos were examined with an electron-microscopic study of development of the internal intercostal somatic nerve. Within 24 h of injection, axons in this nerve became swollen and fused at points along their length. By 48 h after injection no component of the nerve remained in distal segments of ribcage; complete loss of axons and components of the nerve sheath from proximal regions took slightly longer. At later times, no trace of peripheral nerve axons, Schwann cells or elements of the nerve sheath remained. β-Bungarotoxin applied on E17 destroyed developing axons in a similar manner, but the perineurium remained in place, and axons regenerated within the original nerve trunk. The study confirms that sensory and motor neurons are much less able to survive axon degeneration on E14 than after the major period of normal cell death (which is nearly over by E18), and that the maintenance and continued development of the perineurium during E14–E16 depends on the presence of peripheral nerve axons.
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    URL: http://dx.doi.org/10.1007/BF00216545
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    Development of the nervous system of the pluteus larva of Strongylocentrotus droebachiensis (1987)
    Springer
    Cell & tissue research 248 (1987), S. 335-343 
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    ISSN: 1432-0878
    Keywords: Pluteus ; Nervous system ; Development ; Neurotransmitter ; Strongylocentrotus droebachiensis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Development of the nervous system of the pluteus larva of Strongylocentrotus droebachiensis was investigated using indirect immunofluorescence with antibodies against dopamine, GABA, and serotonin, and glyoxylic acid-induced fluorescence of catecholamines. Serotonergic cells first appear in full gastrulae; dopaminergic and GABAergic cells are present in early four-arm plutei. The number of neurons and the complexity of the nervous system increases through development of the pluteus. In the pluteus the dopaminergic component of the nervous system includes a ganglion in the lower lip of the mouth and a pair of ganglia at the base of the post-oral arms which extend axons along the base of the circumoral ciliary band. The distribution of cells visualized by glyoxylic acid-induced fluorescence is similar to that of dopaminergic cells. GABAergic neurons occur in the upper lip and in the wall of the esophagus. Serotonergic neurons are present in the lower lip; the pre-oral hood contains an apical ganglion which extends axons along the base of the epidermis overlying the blastocoel. The dopaminergic and GABAergic components of the nervous system are associated with effectors involved in feeding and swimming. The serotonergic component is not associated with any apparent effectors but may have a role in metamorphosis.
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    URL: http://dx.doi.org/10.1007/BF00218200
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    Thyroxine accelerates the differentiation of granular convoluted tubule cells and the appearance of epidermal growth factor in the submandibular gland of the neonatal mouse (1987)
    Springer
    Cell & tissue research 248 (1987), S. 351-358 
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    ISSN: 1432-0878
    Keywords: Submandibular gland (mice) ; Granular convoluted tubule ; Development ; Thyroid hormone ; Epidermal growth factor ; Immunocytochemistry and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of the administration of thyroxine (T4) on the postnatal cytodifferentiation of granular convoluted tubule (GCT) cells of the submandibular gland (SMG) of Lewiss-Webster mice were studied by light and electron microscopy. From birth, mice of both sexes were injected daily with T4 (sc 0.4 μg/g BW) and were sacrificed 24 h after the last injection at 7, 9, 11, 14 and 21 days of age. Control mice received vehicle only. In control mice, granulated striated duct (SD) cells were first detected at 9 days and 7 days of age by light- and electron microscopy, respectively. Furthermore, a few scattered granulated SD cells were observed by light microscopy as early as day 7 in T4-treated mice of both sexes. At 21 days of age, in mice given T4, GCT cells were larger and more numerous and the Golgi apparatus, rough endoplasmic reticulum, and secretion granules were more abundant. In control mice, immunocytochemical staining for epidermal growth factor-(EGF) was first detectable at day 21 at the light- and electron-microscopic levels. However, positively stained cells were first observed in T4-treated mice by light- and electron-microscopic immunocytochemistry at 14 and 11 days of age, respectively. Moreover, in the 21-day-old T4-treated mice, the number of immunoreactive GCT cells, as well as the intensity of the staining per cell, was markedly increased as compared to controls. EGF immunostaining was restricted to GCT cells, and by immuno-electron-microscopy was only seen in apical secretory granules in granulated SD cells and GCT cells. There were no sex differences in the differentiation of the duct system under any conditions. It is concluded that T4 stimulates the biosynthesis of EGF by an acceleration of the differentiation of the GCT precursor cells to mature cells.
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    The pineal organ is the first differentiated light receptor in the embryonic salmon, Salmo salar L. (1987)
    Springer
    Cell & tissue research 249 (1987), S. 641-646 
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    ISSN: 1432-0878
    Keywords: Pineal organ ; Development ; Photoreceptors ; Retinal S-antigen ; α-Transducin ; Opsin ; Serotonin ; Immunocytochemistry ; Teleosts (Salmo salar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The initial appearance of S-antigen, α-transducin, opsin and 5-HT during embryogenesis of the pineal organ and retina was studied by means of immunocytochemistry in the Atlantic salmon, Salmo salar L. The presence of these substances may be taken as a good indication of photoreceptor differentiation; α-transducin and S-antigen are involved in the phototransduction process, opsin is the proteinaceous component of the photopigment rhodopsin, and 5-HT is a neurotransmitter or neurohormone produced by pineal photoreceptors. Two days after the retinal pigment layer became visible in the eggs, the outer segments of a few pineal photosensory cells showed immunoreactivity to opsin and α-transducin. At the same time S-antigen and serotonin were present in pineal cells of the photoreceptor type. The number of immunoreactive cells in the pineal organ increased up to hatching. In the differentiating retina of the salmon, no immunoreactivity to antibodies raised against the mentioned substances was detectable until after hatching. These results indicate that in ontogeny the developing pineal organ of the salmon embryo has the ability to perceive light information much earlier than the retina.
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    The dorso-lateral recess of the hypothalamic ventricle in neonatal rats (1987)
    Springer
    Cell & tissue research 250 (1987), S. 197-204 
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    ISSN: 1432-0878
    Keywords: Third ventricle ; Intraventricular vessels ; Recess ; Development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Light and electron microscopy of the hypothalamic ventricle in neonatal rats demonstrate morphological specializations of the ventricular wall at the level of the premammillary region of the third ventricle. The morphological features are: (1) A ventricular recess that we have called the “hypothalamic dorso-lateral recess” (HDR). (2) The presence of intraventricular capillaries near the dorsolateral recess. (3) The HDR possessing a specialized ependymal lining; this consists of non-ciliated cells with short microvilli and bleb-like processes. (4) The existence of cerebrospinal fluid-contacting neurons within the HDR. (5) The presence of numerous phagocytic supraependymal cells. The HDR is not found in adult rats. This indicates that the dorso-lateral recess may play a physiological role during development.
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    An immunohistochemical study of adenohypophyseal cells containing follicle-stimulating hormone and luteinizing hormone during the phase of selective follicle-stimulating hormone release in postnatal female rats (1987)
    Springer
    Cell & tissue research 250 (1987), S. 689-693 
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    ISSN: 1432-0878
    Keywords: Anterior pituitary gland ; FSH cells ; LH cells ; Development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Serum concentration of follicle-stimulating hormone (FSH) in the juvenile female rat increases independently from that of luteinizing hormone (LH). The objective of this study was to determine whether this increase in serum FSH is accompanied by a proliferation of FSH-cells greater than the proliferation of LH-cells. Thus, we measured circulating FSH and LH in female rats on days 3, 10, 13, 17, and 20, calculated the percentages of adenohypophyseal cells that contained FSH or LH on days 3, 10, and 20, and determined whether cells containing only FSH existed on day 10. Serum FSH concentrations on days 10 and 13 were significantly greater than those on days 3, 17, or 20. No differences existed in serum LH concentrations. Cells containing FSH or LH were distributed throughout the entire adenohypophyses of 3, 10, and 20-day-old females. Clusters of these cells were observed in the ventral regions of adenohypophyses of 3-day-old females. The percentages of adenohypophyseal cells containing FSH increased significantly from ∼9% in 3-day-old rats to ∼17% in 10-day-old rats and then decreased to ∼14% in 20-day-old animals. At all ages the percentages of adenohypophyseal cells containing FSH were similar to the percentages of cells containing LH. At 10 days of age, all cells containing FSH also contained LH and all cells containing LH also contained FSH. These data suggest that the increase in serum FSH in the juvenile female rat is associated with an increase in the percentage of adenohypophyseal cells containing FSH and that at this time all cells containing FSH also contain LH.
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    Immunohistochemical localization of laminin, neural cell adhesion molecule, collagen type IV and T-61 antigen in the embryonic retina of the Japanese quail by in vivo injection of antibodies (1987)
    Springer
    Cell & tissue research 249 (1987), S. 487-496 
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    ISSN: 1432-0878
    Keywords: Retina ; Development ; Antigen detection ; Axonal pathfinding ; Retinal matrix ; Cell surface molecules ; Coturnix coturnix japonica
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Antibodies against laminin (LN), fibronectin (FN), collagen type IV (Col IV), neural cell adhesion molecule (N-CAM), T-61 antigen, actin, tubulin and neurofilament protein were injected into the eyes of quail embryos (Coturnix coturnix japonica) of different ages. Twenty h after injection, the heads of the embryos were fixed and the antibodies visualized in sections with the use of fluorescein-isothiocyanate (FITC) or peroxidase-labeled second antibodies by light- and electron microscopy. Antibodies against cell surface molecules, such as N-CAM, LN, Col IV and T 61, labeled matrix and membrane components of the retinal cells in different antigen-specific patterns. Antibodies against intracellular antigens, such as actin, tubulin and neurofilament protein labeled nonspecifically the vitreous body and the inner basal lamina of the retina, but resulted in only a very weak and diffuse labeling of retinal cells. N-CAM was detected in high concentration in the optic fiber layer on the surface of axons and on the membranes of all retinal cells. Col IV, LN and T 61 antigen were found predominantly in the optic fiber layer. LN and Col IV were located on the surface of axons and the endfeet of ventricular (neuroepithelial) cells in a patchy distribution. The T-61 antigen was found in early stages in the cell-free space of the optic fiber layer, on the surface of ventricular cells and axons, and at later stages also in high-density patches between nerve fibers. The distribution of LN and T-61 antigen together with data from in vitro experiments suggests a crucial role of these proteins in axon extension in the avian retina during early development of the optic fiber layer.
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    Morphology and development of rhabdovirus-like particles inCuscuta odorata (Convolvulaceae) simultaneous infected with virus and mycoplasma-like organisms (1987)
    Springer
    Protoplasma 139 (1987), S. 130-140 
    Details
    ISSN: 1615-6102
    Keywords: Cytopathology ; Rhabdovirus ; Development ; Electron microscopy ; Cuscuta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Electron microscopic examination ofCuscuta odorata, used for transmission trials, revealed mycoplasma-like organisms (MLO) as well as rhabdovirus-like particles, unknown toCuscuta. The virus infection is confined to certain phloem-parenchyma cells and a 1–2 cell thick layer of parenchyma cells with thickened walls surrounding the central cylinder. Virus particles, mostly bacilliform, could be detected mainly in the nucleus but also in the cytoplasm. They reach a length of 350–400 nm and a diameter of approximately 75 nm. Virus assembly takes place exclusively in the nucleus. Virus maturation occurs in membrane bound areas within the nucleus, which have no connection with the perinuclear space. Formation of nucleocapsids is always associated with a nuclear viroplasm. Envelopment of virus particles occurs in these membrane bound areas. Budding into the perinuclear space does not occur. Virus infection leads to degeneration and finally to death of the protoplast.
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    An ultrastructural study of the viscin tissue ofPhthirusa pyrifolia (H.B.K.) Eichler (Loranthaceae) (1987)
    Springer
    Protoplasma 137 (1987), S. 145-155 
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    ISSN: 1615-6102
    Keywords: Mistletoe fruit ; Phthirusa pyrifolia ; Ultrastructure ; Development ; Viscin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The viscin tissue ofPhthirusa pyrifolia consists at maturity of two different cell types. The first of these (viscin cells) are greatly elongated and have massive secondary walls, the microfibrils of which are arranged strictly transversely, and are soaked with mucilaginous noncellulosic polysaccharides. The second type of cells (vesicular cells) is much broader, with a very extensive vacuolar system and thin primary cell walls only. Viscin cells are capable of being stretched very greatly, the microfibrils of the secondary wall then becoming oriented more or less longitudinally. In nature, this corresponds to the time of attachement to the host surface, and is followed by drying and, possibly, shortening of the viscin cells. Developmental study of the tissue suggests that Golgi bodies are the major organelles participating in polysaccharide production. The actual mucilage seems to originate from three sources: an unorganized substance which accumulates between the plasmalemma and compound middle lamella; spherical vacuoles which seem to be embedded in the central vacuole, some of which are seen open to the outside of the cell; and from the dissolution at maturity of the compound middle lamella. It is suggested that the two types of cells may correspond to the two major functions of viscin, viz., host attachment (viscin cells) and nutrition of the disseminator (vesicular cells).
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    Endophyte differentiation inCasuarina actinorhizae (1987)
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    Protoplasma 136 (1987), S. 104-117 
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    ISSN: 1615-6102
    Keywords: Actinomycete ; Casuarina ; Development ; Frankia ; Root ; nodules ; Symbiosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This is an ultrastructural study of development of infected cells in nitrogen fixing root nodules ofCasuarina spp. While several aspects of development are similar to those found in many other actinorhizae, unusual aspects of development of the host cell and differentiation of the endophyte inCasuarina are correlated with unusual changes in the wall of the infected cell. Instead of vesicles the endophyte forms atypical hyphae in mature infected cells. These unusual hyphal forms are termed intracellular hyphae. Intracellular hyphae are nonseptate hyphae which originate and terminate within the same host cell, and have a varying diameter and a multidirectional growth and branching pattern. A laminate surface layer previously undescribed on hyphae ofFrankia is a feature common to mostCasuarina endophytic hyphae and is probably similar chemically to the laminae comprising the multilamellate envelope of endophytic vesicles in other actinorhizae.
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    Growth and development in relation to the cell cycle inPhysarum polycephalum (1987)
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    Protoplasma 141 (1987), S. 101-111 
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    ISSN: 1615-6102
    Keywords: Cell cycle ; Development ; Physarum ; Slime mould
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In strain CL ofPhysarum polycephalum, multinucleate, haploid plasmodia form within clones of uninucleate, haploid amoebae. Analysis of plasmodium development, using time-lapse cinematography, shows that binucleate cells arise from uninucleate cells, by mitosis without cytokinesis. Either one or both daughter cells, from an apparently normal amoebal division, can enter an extended cell cycle (28.7 hours compared to the 11.8 hours for vegetative amoebae) that ends in the formation of a binucleate cell. This long cycle is accompanied by extra growth; cells that become binucleate are twice as big as amoebae at the time of mitosis. Nuclear size also increases during the extended cell cycle: flow cytometric analysis indicates that this is not associated with an increase over the haploid DNA content. During the extended cell cycle uninucleate cells lose the ability to transform into flagellated cells and also become irreversibly committed to plasmodium development. It is shown that commitment occurs a maximum of 13.5 hours before binucleate cell formation and that loss of ability to flagellate precedes commitment by 3–5 hours. Plasmodia develop from binucleate cells by cell fusions and synchronous mitoses without cytokinesis.
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    Object manipulation in a captive troop of Japanese monkeys (Macaca fuscata): A developmental analysis (1987)
    Springer
    Primates 28 (1987), S. 497-506 
    Details
    ISSN: 0032-8332
    Keywords: Object manipulation ; Japanese monkey ; Development ; Focal object sampling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A captive troop of Japanese monkeys (Macaca fuscata) was presented with a nylon rope, a wooden cube, and an iron tube, and their subsequent manipulations were observed in detail. In total, 202 manipulation patterns were distinguished on the basis of three components: the actions performed, body-parts used, and relations to other objects. The developmental changes in these modes of manipulation were analyzed cross-sectionally, revealing four characteristics: (1) the most manipulative members of the troop were those aged 2–3 and 4–6 years old; (2) most of the manipulatory repertoire appeared by 4–6 years old; (3) actions such as Roll, Rub, and Slide and the use of bodyparts continued to increase in variety until 4–6 years old, while the variety of other actions showed plateaus after 2–3 years old or an earlier age; and (4) secondary manipulations appeared at 1 year old and continued to increase in variety even after 4–6 years old.
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    URL: http://dx.doi.org/10.1007/BF02380863
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    Sibships: Cooperation and competition among immature vervet monkeys (1987)
    Springer
    Primates 28 (1987), S. 47-59 
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    ISSN: 0032-8332
    Keywords: Sibling ; Cercopithecus aethiops ; Competition ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The relationships between siblings were compared with those between non-sibling peers amongst immature vervet monkeys (Cercopithecus aethiops) in three free-ranging social groups. Using the frequency and context of friendly, supportive, aggressive, and competitive interactions, sibships were found to stand out as associative units characterized by high levels of grooming and support during aggression. Competition between siblings was related to contests over access to maternal care, especially grooming, which may have been important in the establishment of relative sibling dominance. Siblings who were close in age tended to interact more frequently than those who were distant in age, but few sex differences were found. The close and supportive nature of sibling relationships appeared to affect the social structure of the groups.
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    URL: http://dx.doi.org/10.1007/BF02382182
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    The effect of early experience on aggression in two territorial scorpaenid fishes (1987)
    Springer
    Environmental biology of fishes 19 (1987), S. 183-194 
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    ISSN: 1573-5133
    Keywords: Development ; Behavior ; Population density ; Shelter availability ; Sibling species ; Reef fish ; Rockfish ; Scorpaenidae ; Sebastes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The impact of population density and shelter availability on the development of aggressive behavior in two species of rockfishes, the black and yellow rockfish, Sebastes chrysomelas, and the gopher rockfish, Sebastes carnatus, were examined in this study. Adults of these species are typically territorial though other patterns of space utilization are observed. Dominance does not appear to account for these patterns. Since the level of aggressiveness seems to vary between groups, differences in early experience might play a role in determining adult behavior patterns. Laboratory experiments were performed on juveniles captured prior to settlement in which the aggressive tendencies of individuals were assessed by focusing on the development of displays toward a mirror image over a six month period. The results of this study suggest that the repertoire of agonistic behaviors used by adults is available to juveniles though seldom seen in the field. Increased population density and the availability of a shelter increase aggressiveness in S. carnatus and the effects of density were not reversible over the course of the experiment. The behavior of S. chrysomelas was less influenced by the manipulations.
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    URL: http://dx.doi.org/10.1007/BF00005348
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    Developmental changes in the isoenzymes controlling glycolysis in the acridine grasshopper,Caledia captiva (1986)
    Springer
    Development genes and evolution 195 (1986), S. 197-201 
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    ISSN: 1432-041X
    Keywords: Glycolysis ; Isoenzymes ; Housekeeping ; Grasshopper ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In this paper is reported an example of extensive developmental changes in the isoenzymes controlling a biochemical pathway: more than half of the glycolytic enzymes of the grasshopper,Caledia captiva differ in electrophoretic phenotype between embryonic and adult stages. A similar pattern of changes is found in each of the taxa ofC. captiva, which is actually a species complex. The present example of developmental variation differs from that described for glycolytic enzymes in vertebrates in two main points. Firstly, the changes between the phenotypes of the embryos and adults are co-incident in time, occurring near hatching. Secondly, in contrast to vertebrates where embryospecific isoenzymes are rare, there exist inC. captiva isoenzymes of trehalase, glucosephosphate isomerase, aldolase, pyruvate kinase, lactate dehydrogenase and 6-phosphogluconate dehydrogenase which are found in the embryo but not in the adult. Some of the variable enzymes also exhibit tissue specificity in the adult. The existence of the changes, whatever their basis, shows that the theory that the expression of housekeeping genes is developmentally invariant is not generally correct.
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    URL: http://dx.doi.org/10.1007/BF02439439
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    The plurennial life cycles of the European Tettigoniidae (Insecta: Orthoptera) (1986)
    Springer
    Oecologia 70 (1986), S. 606-616 
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    ISSN: 1432-1939
    Keywords: Tettigoniidae ; Development ; Temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The effect of temperature on embryonic development, voltinism, and hatching was studied in the laboratory in eggs of 21 Central and Southeastern European Tettigoniidae species. In most species, the embryo has to arrive at a postkatatrepsis stage prior to the onset of cold to be able to hatch in the following spring. The rate of embryonic development differs: quickly developing species need 4 weeks at 24°C (prior to cold) and almost all eggs hatch after the first cold treatment, slowly developing species would need 8–12 weeks to do the same. In Central Europe, warmth is not enough for the slowly developing species to have an univoltine life cycle, but they could have it in southern Europe. Most species make use of a dormancy sequence to pass successive winters as follows: an initial embryonic dormancy (either quiscence or diapause in embryonic stage 4) and a final diapause in embryonic stage 23/24. Additionally, 3 forms of aestivation or summer dormancy were observed facultatively: an initial diapause in embryonic stage 4 (induced and terminated at 30°C), a median dormancy shortly before or after katatrepsis (at 30°C), and a penultimate diapause in embryonic stage 20 (at 24°C). The life cycles of the European Tettigoniidae species can follow one of 3 types: 1. annual life cycle (no initial embryonic dormancy); 2. annual or biennial depending on whether laid early or late; 3. biennial or many year life cycle (up to 8 years due to a prolonged initial diapause).
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    The plurennial life cycles of the European Tettigoniidae (Insecta: Orthoptera) (1986)
    Springer
    Oecologia 70 (1986), S. 617-623 
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    ISSN: 1432-1939
    Keywords: Photoperiod ; Tettigoniidae ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In eggs of European Tettigoniidae species, an initial diapause can occur just after blastoderm formation and a final diapause close to the end of embryonic development. The effect of photoperiod experienced maternally on the induction of the initial diapause was studied, using 13 species from Central and Southeastern Europe. In Conocephalus dorsalis and Platycleis albopunctata there was no initial diapause induced by photoperod, while, in Tettigonia-and Saga-species and in Metrioptera saussuriana it occurred independently of day length. In Metrioptera roeseli, M. bicolor, Leptophyes punctatissima, Eupholidoptera smyrnensis, and Decticus verrucivorus, oviposition at short day induced an initial diapause, while after oviposition at long day, the eggs developed directly until final diapause. On the other hand, in up to 1/4 of the eggs of Pholidoptera griseoaptera an initial diapause was induced by long day length. Populations of D. verrucivorus from different latitudes differed with respect to the critical day length. For E. smyrnensis and M. roeseli, a photoperiodic response curve was calculated. In the Rhodian population of E. smyrnensis, the dormancy sequence of initial and final embryonic diapause can be used for aestivation and hibernation within an annual life cycle, while enabling hibernation in successive years for the Central European species. The population of D. verrucivorus near Aachen has an “obligatory” plurennial life cycle, since the critical day length for development without initial diapause is above the range of day length occurring in the field.
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    Interconnections between the stereovilli of the fish inner ear (1986)
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    Cell & tissue research 246 (1986), S. 447-453 
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    ISSN: 1432-0878
    Keywords: Vestibular organ ; Hair cells ; Stereocilia ; Development ; Differentiation ; Teleosts (Rutilus rutilus)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The maculae utriculi and sacculi of the inner ear from the European roach (Rutilus rutilus) were investigated by transmission electron microscopy. The stereovilli of peripherally and centrally located sensory cells differ in several features that suggest a developmental gradient. The stereovilli of the peripheral sensory cells, shown to be differentiating cells by other research groups, are short and less steeply graded in height than in central hair cells. All stereovilli in both kinds of hair bundles are interconnected. In the central bundles of stereovilli basal, tip, and vertical connectors are separated by unconnected regions. In contrast, filaments and sometimes other additional structures connect the stereovilli of peripheral bundles over their entire length, but vertical connectors are usually absent. Osmiophilic material occurring inside peripheral stereovilli is interpreted to be monomeric actin. Central and peripheral hair bundles also differ in their reaction to ruthenium red and cationized ferritin. Only the stereovilli of the central cells can be fused by these polycations. Ruthenium red also discriminates between supporting and sensory cells indicating differences in amount or distribution of extracellular material. Hair bundles, intermediate in properties and position between central and peripheral sensory cells, were also found, so that it became possible to propose a scheme of developmental steps leading from microvilli or microvillus-like stereovilli to the fully differentiated hair bundle.
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    Maturation of tight junctions in guinea-pig cecal epithelium (1986)
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    Cell & tissue research 246 (1986), S. 169-175 
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    ISSN: 1432-0878
    Keywords: Tight junctions ; Freeze-fracture ; Development ; Cecal epithelium ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By means of the freeze-fracture technique and in tracer studies it is demonstrated that the structure of tight junctions and the permeability to lanthanum of the guinea-pig cecal epithelium change during maturation of cells. Height and strand number of tight junctions in the apical-basal direction increase as crypt cells migrate to the surface of the epithelium. Likewise, the interlacing of continuous strands was greater in surface than in crypt junctions. The numerous free-ends, isolated individual freestrands and maculae occludentes found in crypt cells were absent in surface epithelial cells. Goblet cells, located at the bottom of crypts, displayed tight junctions similar in characteristics to those of cells located in the middle region of crypts. Cells at the surface and in middle regions of crypts possess tight junctions impermeable to lanthanum, whereas junctions between cells located at the bottom of crypts often were permeable to the tracer, indicating that permeability decreases as the epithelial cells mature. Genesis and maturation mechanisms related to structural configuration of tight junctions are discussed.
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    Cellular localization of the Ca2+-binding protein parvalbumin in the developing avian cerebellum (1986)
    Springer
    Cell & tissue research 243 (1986), S. 69-78 
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    ISSN: 1432-0878
    Keywords: Ca-binding protein ; Parvalbumin ; Cerebellum ; Development ; Birds ; Zebra finch, Poephila guttata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The appearance and distribution of the calciumbinding protein parvalbumin was investigated immunocytochemically at different postnatal developmental stages of the zebra finch cerebellum. Purkinje, basket and stellate, but not granule neurons or glial cells were labeled by an antiserum against chicken parvalbumin. At all developmental stages investigated immunostained Purkinje cells were found in clusters separated by spaces containing unstained large cells, probably Purkinje and Golgi type-II cells, and unstained smaller cells resembling granule neurons. Perisomatic processes, dendrites and spines of Purkinje cells were heavily immunoreactive. Axons of Purkinje cells were observed to be parvalbumin-positive throughout their entire length until developmental stage D 24, i.e., 10 days after hatching. Their immunoreactivity gradually decreased up to adulthood, when only their proximal portions, in addition to a few punctate structures in the internal granular layer and in the deep cerebellar nuclei presumably representing the synaptic terminals, remained immunoreactive. This decrease in immunoreactivity might be related to progressive maturation and/or degree of myelination. The developmental expression of parvalbumin immunoreactivity and its ultrastructural localization in spines, postsynaptic densities and on microtubular elements leads to several suggestions concerning the possible function of parvalbumin in neurons. In outgrowing dendrites and axons the protein might be involved in the regulation of the synthesis of membrane components, their intracellular transport and fusion of new membrane components into the plasmalemma, events that are Ca- and/or Mg-dependent. In spines and postsynaptic densities parvalbumin might be involved in the development and regulation of synaptic activities in Ca-spiking elements such as the inhibitory Purkinje cells, and possibly also in stellate and basket cells. Furthermore, in developing and adult neurons parvalbumin might be involved in the Ca-/Mg-regulation of a variety of enzymatic activities and hence influence the alteration of the intracellular metabolic potential in response to extracellular signals.
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    Ontogenesis of corticotropes and lactotropes in situ in the pituitary gland of the hamster (1986)
    Springer
    Cell & tissue research 245 (1986), S. 673-679 
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    ISSN: 1432-0878
    Keywords: Pituitary gland ; ACTH cells ; PRL cells ; Immunohistochemistry ; Development ; Mesocricetus auratus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of corticotropes and lactotropes was investigated in the golden Syrian hamster using an anti-porcine ACTH antiserum and a homologous antihamster PRL antiserum. Oval corticotropes were first visible in the ventral region of the pars distalis at 13 days of gestation. By the end of gestation, corticotropes were found throughout the pars distalis and in the pars intermedia. Corticotropes in the pars distalis of postnatal hamsters were either round or irregularly-shaped, often appearing in clusters. Throughout development, corticotropes often appeared to be surrounding other cells. Scarce, very small lactotropes were first observed in the pars distalis of hamsters on the first postnatal day. The number of these cells, which were either round or polyhedral, increased dramatically between 4 and 20 days of postnatal life. These observations indicate that the sequence of appearance of corticotropes and lactotropes in the hamster is similar to that in other species and that lactotropes are confined to the pars distalis of postnatal hamsters.
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    Analysis of the expression of two genes of Dictyostelium discoideum which code for developmentally regulated cysteine proteinases (1986)
    Springer
    Molecular genetics and genomics 203 (1986), S. 333-340 
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    ISSN: 1617-4623
    Keywords: Dictyostelium ; Cysteine proteinases ; Development ; Regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We analysed the expression of two genes encoding two different cysteine proteinases which show a high degree of homology and are regulated differentially during Dictyostelium discoideum development. While absent from growing vegetative cells, the two specific messengers RNAs appear at an early stage of development but accumulate in the polysomes at different later stages of development. The message coding for cysteine proteinase I reaches its maximum level after the aggregative period while cysteine proteinase II mRNA reaches its maximum during the culmination stage. At these times they represent 1% and 0.7%, respectively, of cellular mRNA and belong to the most abundant class of mRNAs. No accumulation of the two messages elsewhere than in the polyribosomes was observed in the cytoplasm of the cells, whatever the stage of development analysed. Results of analysis of the nuclear levels of RNA complementary to the two genes are in agreement with the relative transcription rates determined by in vitro transcription of nuclei isolated at different stages. The combined results of these measurements demonstrate that the expression of the cysteine proteinase I and II genes is mainly under transcriptional control. However, the difference between the RNA synthetic rate in the nucleus and the accumulation of the mRNA in the cytoplasm, indicates an additional post-transcriptional regulation for the cysteine proteinase II gene.
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    Cat-2 gene expression (1986)
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    Molecular genetics and genomics 203 (1986), S. 185-188 
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    ISSN: 1617-4623
    Keywords: Catalase ; Gene expression ; Cat2-mRNA ; Maize ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Poly(A)4 RNA was isolated from maize scutella of different stages of post-germinative development and translated in vitro in a rabbit reticulocyte translation system. Immunoprecipitation of the translation products with CAT-2-specific antibody was used to quantitate the relative levels of translatable CAT-2 mRNA at each stage. The results show a close correlation between the developmental profile of Cat2 gene expression and the profile of CAT-2 mRNA levels. Evidence that the levels of CAT-2 mRNA are regulated by a temporal regulatory gene (Car1) is presented and the possible mechanism(s) of this regulation discussed.
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    URL: http://dx.doi.org/10.1007/BF00330401
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    Events in the amoebal-plasmodial transition ofPhysarum polycephalum studied by enrichment for committed cells (1986)
    Springer
    Protoplasma 132 (1986), S. 149-159 
    Details
    ISSN: 1615-6102
    Keywords: Physarum ; Commitment ; Development ; Tubulin ; Flagellation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Amoebae of strain CLof Physarum polycephalum undergo apogamic development to form multinucleate plasmodia. During the amoebalplasmodial transition, large uninucleate cells become irreversibly committed to plasmodium development. In developing cultures, amoebae lose the ability to flagellate before they become committed. Enriched suspensions of committed cells can be obtained by inducing asynchronous differentiating cultures to flagellate and passing the cells through a glass bead column. Committed cells can be cultured to form plasmodia on bacterial lawns or in axenic liquid medium but cannot be cultured on axenic agar medium. Uninucleate committed cells express tubulin isotypes characteristic of amoebae, but after culture in axenic liquid medium, the cells express plasmodial specific tubulin isotypes.
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    Japanese macaques (Macaca fuscata) social development: Sex differences in Juvenile behavior (1986)
    Springer
    Primates 27 (1986), S. 141-150 
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    ISSN: 0032-8332
    Keywords: Macaques ; Sex differences ; Development ; Juveniles ; Behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have quantitatively documented the development of sex differences in the behavior of juvenile Japanese macaques (1 to 2 years of age). Mothers treated their offspring differently by sex, i.e., mothers of males broke contact with them more frequently than did mothers of females. Juvenile males played more, and mounted other macaques more frequently; juvenile females groomed their mothers more and were also punished by other group members more frequently than were males. Males showed a pattern of decreasing interactions with their mothers, but females increased the frequency of their maternal interactions. These patterns appear to presage the life histories of the sexes. However, comparisons with other species of nonhuman primates indicate that although sex differences in behavior are common, the variability among species severely limits cross-specific generalizations.
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    A model (WHTROOT) which synchronizes root growth and development with shoot development for winter wheat (1986)
    Springer
    Plant and soil 92 (1986), S. 133-145 
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    ISSN: 1573-5036
    Keywords: Development ; Model ; Root ; Shoot ; Thermal time ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary A model has been developed of root growth in winter wheat based on cumulative thermal time with description of the extension and branching of individual age classes of seminal and crown root axes. The model requires, as input, the sowing date and average monthly mean air temperatures and gives, as output, the maximum depth of penetration of each age class of root and the root length density or root weight in any 10 cm layer of soil contributed by main axes, first-order and second-order laterals on any calendar date. The impact of soil temperature on root length density distributions with time was assessed by comparing a warm site (Perth, Australia) with a cool site (Rothamsted Experimental Station, England). Simulated values of root length density for plants with six leaves were consistently high when soil temperature was held constant at 10°C, but variable soil temperatures at each site resulted in rooting profiles characteristic for the two sites, although root length densities were larger than commonly observed at either location. The model simulates well described sequences of root production and permits calculation of maximal root development rates for unstressed plants growing in moist soil with no mechanical impedance to growth. It allows the co-development of root and shoot to be modelled and since it uses only about 5 K bytes of computer memory could be easily used for the assessment of management practices in the field.
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    The physiology of digestion in fish larvae (1986)
    Springer
    Environmental biology of fishes 16 (1986), S. 59-77 
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    ISSN: 1573-5133
    Keywords: Alimentary canal ; Morphology ; Histology ; Histochemistry ; Enzymology ; Assimilation ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The acquisition, digestion, and assimilation of food is critical for the growth and survival of fish larvae; a fish larva either grows or it perishes. Fish larvae are characterized by digestive systems and diets that differ from adults. Larvae undergo a pattern of trophic ontogeny, changing diet with increasing size, and these changes result in differences in digestive requirements. At first feeding, the larval alimentary canal is functional, but is structurally and functionally less complex than that of adults. The larval alimentary canal remains unchanged histologically during the larval period before transformation. During transformation, major changes that result in the development of the adult alimentary canal occur. The ontogeny of the alimentary canal differs in different taxa, and experimental evidence suggests that functional differences exist as well. Assimilation efficiency may be lower in larvae than it is in adult fishes, due to a lack of a morphological and functional stomach in larvae, but the question of improving assimilation efficiencies during larval development before transformation remains unresolved.
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    Moth ocellar interneurons show abnormal development in the absence of receptor innervation (1985)
    Springer
    Cellular and molecular life sciences 41 (1985), S. 111-112 
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    ISSN: 1420-9071
    Keywords: Development ; interneurons ; moth ; ocellus ; Trichoplusia ni ; Lepidoptera: Noctuidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Unilaterally ocellate adult moths were produced by cauterization of one of the pair of ocellar primordia in fifth instar larvae. The remaining ocellar nerves and associated interneurons of the adult moths were subjected to cobalt infiltration and Timm's intensification. Two interneurons from the ablated ocellus were observed to grow into the synaptic region of the remaining ocellus and presumably made functional connections with ocellar receptor cell axons.
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    Myelogenesis and estimation of the number of axons in the anterior commissure of the chick (Gallus gallus) (1985)
    Springer
    Cell & tissue research 239 (1985), S. 661-666 
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    ISSN: 1432-0878
    Keywords: Anterior commissure ; Development ; Morphometry ; Myelogenesis ; Aves ; Gallus gallus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By use of light- and electron microscopy the anterior commissure of the chick was studied at different times during development. Between the 19th day of incubation and the 35th day after hatching the cross-sectional area of the anterior commissure, as determined from mid-sagittal sections, undergoes a 6-fold increase in size. Thereafter the area remains fairly constant. The total number of fibres in the anterior commissure was estimated to be 89000. The full complement of fibres is already present by the 19th day of incubation. Myelogenesis occurs mainly between the 19th day of incubation and the 35th day after hatching, concomitant with the increase in cross-sectional area. From the 35th day after hatching, myelinated fibres comprise approximately 40% of the total number of fibres. The median diameter of unmyelinated fibres is about 0.35–0.40 μm. The median diameters of myelinated axons and fibres are 0.8–1.0 μm and 1.1–1.3 μm, respectively.
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    Demonstration of the granular layer and the fate of the hyaline layer during the development of a sea urchin (Lytechinus variegatus) (1985)
    Springer
    Cell & tissue research 239 (1985), S. 455-458 
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    ISSN: 1432-0878
    Keywords: Development ; Sea urchin ; Hyaline layer ; Granular layer ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Employing electron-microscopic methods that help retain polyanionic materials, we describe the extracellular coverings of a sea urchin (Lytechinus variegatus) throughout ontogeny. The surface of the embryo is covered by a two-layered cuticle (commonly called the hyaline layer), which in turn is covered by a granular layer. The granular layer is retained after addition of alcian blue to the fixative solutions, and has not been previously described for any sea urchin. After hatching, the granular layer disappears, but the hyaline layer continues to cover most of the larval surface until settlement and metamorphosis. A few days before metamorphosis, the hyaline layer lining the vestibular invagination of the competent pluteus larva is replaced by a three-layered cuticle resembling that of the adult sea urchin. The hyaline layer covering the rest of the larva is evidently lost at metamorphosis during the involution of the general epidermis.
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    URL: http://dx.doi.org/10.1007/BF00218028
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    Midbody sealing after cytokinesis in embryos of the sea urchin Arabacia punctulata (1985)
    Springer
    Cell & tissue research 240 (1985), S. 287-292 
    Details
    ISSN: 1432-0878
    Keywords: Cytokinesis ; Dye coupling ; Development ; Embryo ; Microinjection ; Sea urchin Arabacia punctulata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cytokinesis consists of a contractile phase followed by sealing of the connecting midbody to form two separated cells. To determine how soon the midbody sealed after cleavage furrow contraction, the fluorescent dye Lucifer Yellow CH(457.3 M.W.) was microinjected into cells at various intervals after cleavage had begun. Mitotic PtK2 cells were recorded with video-microscopy so that daughter cells in the epithelial sheet could be identified for several hours after cell division. One daughter cell of each pair followed was microinjected to determine whether the dye diffused into the other daughter cell. For intervals up to four hours after the beginning of cytokinesis, diffusion took place between daughter cells. After this time the dye did not spread between daughter cells. In sea urchin blastomeres of the first, second and third divisions, Lucifer Yellow passed between daughter blastomeres only during the first 15 min after cytokinesis. If one cell of a two-cell, four-cell or eight-cell embryo was microinjected more than 15 min after the last cleavage, the dye remained in the injected cell and was distributed to all progeny of that cell, resulting in blastulae that were either one-half, one-quarter or one-eighth fluorescent, respectively. Thus, although cleavage furrow contraction takes approximately the same amount of time in sea urchin blastomeres and PtK2 cells, the time of midbody sealing differs dramatically in the two cell types. Our results also indicate the importance of knowing the mitotic history of cells when injecting dyes into interphase cells for the purpose of detecting gap junctions.
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    Structure of tendon organs of the rat after neonatal de-efferentation (1985)
    Springer
    Cell & tissue research 241 (1985), S. 229-236 
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    ISSN: 1432-0878
    Keywords: Tendon organs, rat ; Neonatal de-efferentation ; Development ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The number, size and structure of tendon organs were examined in leg muscles of the rat 3–19 weeks after de-efferentation performed in newborn animals by removal of the lumbosacral spinal cord. After this operation, tendon organs differentiated and grew in disused muscles and were innervated by primary sensory neurons, the dorsal roots of which had been disrupted. Three weeks after de-efferentation extensor digitorum longus muscles contained 14.1±1.0 (mean±standard error) and soleus muscles had 14.2±1.6 tendon organs, which corresponds to the mean number of tendon organs in the respective control muscles. The mean size of tendon organs was, however, changed. Tendon organs became on the average by 53% longer and by 35% thinner in de-efferented extensor digitorum longus muscles that were prolonged due to immobilization, as compared with shorter and wider tendon organs in de-efferented soleus muscle that remained in the shortened position. The ultrastructural differentiation of tendon organs was completed after the operation as under normal conditions. Thus it can be concluded that elimination of muscle function during the period of postnatal development indirectly affects the mean size of these receptors, but does not otherwise interfere with their morphogenesis.
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    URL: http://dx.doi.org/10.1007/BF00214645
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    The development of the human spleen (1985)
    Springer
    Cell & tissue research 242 (1985), S. 579-592 
    Details
    ISSN: 1432-0878
    Keywords: Fetal human spleen ; Development ; Differentiation ; Red and white pulp ; T-cell regions ; B-cell regions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Splenic tissue of human fetuses from the 14th to the 24th week of gestation (menstrual age) were investigated by light- and electron microscopy to describe the development of the red and white pulp in close relationship to the differentiation of the vascular tree. Special interest is focussed on the differentiation of the T-cell- and the B-cell regions and their specific stationary cells. The preliminary stage, here called the “primary vascular reticulum,” lasts up to the 14th gestational week (gw). Numerous erythrocytes, normoblasts and macrophages are seen among a network of mesenchymal cells and argyrophilic fibers. Hematopoiesis, especially erythropoiesis, can be recognized. The characteristic organ structure becomes established during the subsequent transformation stage of the fetal spleen, beginning with the 15th gw. Splenic lobules begin to form during the 15th to 17th gw. They consist of a central artery, surrounded by a sheath of lightly stained stationary cells which resemble myofibroblasts. At the periphery of these lobules the red pulp forms. Initially mobile cells are distributed throughout the reticulum. Soon they begin to accumulate in the venous sinuses, which develop from lacunae among the reticular network and come into contact with the venous system. The endothelial wall of these sinuses remains discontinuous, confirming the theory of the “open” vascularization of the spleen. The development of the larger veins is correlated with the differentiation of the splenic trabeculae. The development of the white pulp is correlated with the stage of lymphoid colonization within the spleen, beginning around the 18th gw. An accumulation of lymphocytes around the central arteries can be recognized during the 19th and 20th gw. These lymphoid cells show morphological and immunohistochemical characteristics of T-precursor cells. Within the now assembling periarterial lymphoid sheath (PALS) a few precursors of interdigitating cells (IDC) are recognizable, giving evidence for the differentiation of the T-cell region. Around the 23rd gw the assemblage of primary follicles is discernible at the periphery of the PALS. Precursors of the follicular dendritic reticulum cell (FDRC), the specific stationary cell of the B-cell region, have been recognized. This observation leads to the conclusion that the small primary follicles represent the beginning formation of the B-cell region. The significance of the vascular system for the differentiation of the specific splenic organization is discussed.
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    URL: http://dx.doi.org/10.1007/BF00225424
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    The initiation, development and structure of root nodules inElaeagnus angustifolia L. (Elaeagnaceae) (1985)
    Springer
    Protoplasma 128 (1985), S. 107-119 
    Details
    ISSN: 1615-6102
    Keywords: Actinorhizal root nodules ; Development ; N2 fixation ; Elaeagnus ; Frankia ; Symbiosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A correlated light and electron microscopic study was undertaken of the initiation and development of root nodules of the actinorhizal tree species,Elaeagnus angustifolia L. (Elaeagnaceae). Two pure culturedFrankia strains were used for inoculation of plants in either standing water culture or axenic tube cultures. Unlike the well known root hair infection of other actinorhizal genera such asAlnus orMyrica the mode of infection ofElaeagnus in all cases was by direct intercellular penetration of the epidermis and apoplastic colonization of the root cortex. Root hairs were not involved in this process and were not observed to be deformed or curled in the presence of the actinomyceteFrankia. In response to the invasion of the root, host cells secreted a darkly staining material into the intercellular spaces. The colonizingFrankia grew through this material probably by enzymatic digestion as suggested by clear dissolution zones around the hyphal strands. A nodule primordium was initiated from the root pericycle, well in advance of the colonizingFrankia. No random division of root cortical cells, indicative of prenodule formation was observed inElaeagnus. As the nodule primordium grew in size it was surrounded by tanninised cells of a protoperiderm. The endophyte easily traversed this protoperiderm, and once inside the nodule primordium cortex ramified within the intercellular spaces at multiple cell junctions. Invasion of the nodule cortical cells occurred when a hyphal branch of the endophyte was initiated and grew through the plant cell wall, again by apparent enzymatic digestion. The plant cell plasmalemma of invaded cells always remained intact and numerous secretory vesicles fused with it to encapsulate the advancingFrankia within a fibrous cell wall-like material. Once within the host cell some endophyte cells began to differentiate into characteristic vesicles which are the presumed site of nitrogen fixation. This study clearly demonstrates that alternative developmental pathways exist for the development of actinorhizal nitrogen-fixing root symbioses.
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    Development in Japanese macaques (Macaca fuscata): Sexually dimorphic behavior during the first year of life (1985)
    Springer
    Primates 26 (1985), S. 238-247 
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    ISSN: 0032-8332
    Keywords: Sexual dimorphism ; Development ; Macaques
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have documented several sexually dimorphic patterns of behavior that develop during the first year of life in infant Japanese macaques and their mothers. Mothers treated their infants differently by sex—mothers of males broke contact with them and retrieved them more frequently than did mothers of females. And mothers of male infants moved more frequently than did mothers of female infants. Male infants played more, played in larger groups, and mounted more frequently; female infants groomed and spent more time close to other monkeys in larger social groups than did males. Female infants were also punished by other group members more frequently than were male infants. We conclude that male and female Japanese macaque infants receive differential treatment early in life by both their own mothers and other animals, and males and females in turn treat their mothers and other animals differently. There appears to be a reciprocal relationship between the behavior of infants, mothers and other social partners that contributes to the development of sexually dimorphic patterns of behavior.
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    Mating behavior, egg deposition, incubation period, and hatching in the clearnose skate, Raja eglanteria (1985)
    Springer
    Environmental biology of fishes 13 (1985), S. 161-171 
    Details
    ISSN: 1573-5133
    Keywords: Chondrichthyes ; Elasmobranchii ; Batoidei ; Rajidae ; Reproduction ; Oviparity ; Egg case ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Adult clearnose skates, Raja eglanteria, were captured during the winters of 1981 and 1983, and observed to mate in captivity. Mating and egg depositions take place on the central west coast of Florida from December through mid-May. During copulation the male holds the trailing edge of the female's right or left pectoral fin firmly in his mouth, swings his tail beneath hers and inserts one clasper into the distal end of her reproductive tract. Copulation may last one to four hours during which time sperm pass from the urogenital papilla of the male along the clasper groove to the female. Sperm move cranially to the upper portion of the shell gland where they are stored and remain viable for at least three months. The ovum is fertilized in the shell gland. The egg case bears a prominent projection or ‘horn’ at each corner. The two posterior ones are shorter and bear tendrils which are covered with a sticky substance that insures attachment to the substrate when the egg is deposited. Fertilized eggs are laid in pairs at intervals ranging from 1 to 13 days (mean of 4.5 ± 2.2 days). As development proceeds within the egg case a plugged slit on the lateral side of each horn opens and permits seawater to wash the developing embryo. Incubation periods for eggs maintained between 20–22°C decrease in duration throughout the egg laying season, ranging from 94 days initially to 77 days for eggs laid later in the spring. At hatching, the anterior end of the egg case ruptures, and the skate emerges abruptly with its pectoral fins rolled dorsally.
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    Artificial spawning and rearing of lake sturgeon, Acipenser fulvescens, in Wild Rose State Fish Hatchery, Wisconsin, 1982–1983 (1985)
    Springer
    Environmental biology of fishes 14 (1985), S. 79-85 
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    ISSN: 1573-5133
    Keywords: Propagation ; Juveniles ; Larvae ; Embryos ; Eggs ; Survival ; Diet ; Insemination ; Hatching ; Development ; Stocking
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Attempts to culture lake sturgeon, Acipenser fulvescens, in the past have generally met with limited success. The Wisconsin Department of Natural Resources has been experimenting with artificial propagation of this species since 1979. The intent has been to develop egg collection and handling techniques, hatching regimes, larva and juvenile diet formulations, and to evaluate juvenile survival after stocking. Eggs were collected by caesarian section and fertilized with milt from ripe males taken during annual sturgeon spawning runs on the Fox and Wolf rivers in central Wisconsin. After insemination, the eggs were treated in a saturated solution of Bentonite clay and transported to the hatchery. Eggs were incubated at temperatures ranging from 13–16° C and embryos began hatching within 4 to 8 days. Hatching success ranged from 42 to 96%. Yolksac absorption was complete within 10 days of hatching. Larvae then became positively phototactic and swam actively as if searching for food. Successful larval diets consisted of live brine shrimp nauplii followed by larger zooplankton, primarily Daphnia sp. Juveniles grew best on diets of live Tubifex sp. and chopped earthworms. Liver, fish mash (ground up trout) and pelleted dry food were poorly accepted. Hatchery reared sturgeon grew more slowly than did wild fish.
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    Effects of CCC and GA on internodal development of barley (1985)
    Springer
    Plant and soil 86 (1985), S. 291-294 
    Details
    ISSN: 1573-5036
    Keywords: CCC ; GA ; Development ; Barley
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The effect of applying (2-chloroethyl)trimethylammonium chloride (CCC) or gibberellic acid (GA) as foliar sprays on internodal development of barley was studied. CCC applied to the whole plant at main tiller leaf stages 1, 2 or 3 decreased shoot elongation, and prevented elongation of internode 6 (internode 5 subtended the head). CCC at all stages delayed senescence of the lower leaves. CCC sprayed at all 6 leaf stages and GA sprayed at main tiller leaf stages 1, 2, 3 or 4 reduced plant height at maturity. GA treatment at leaf stages 2, 3 or 4 initially stimulated internodal elongation; elongation of later developed internodes was inhibited resulting in shorter plants at maturity. Only the treatment with GA at leaf stages 5 and 6 resulted in increased plant height.
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    Color polymorphism in siblingAmphiprion: is the reef-fish lottery rigged? (1985)
    Springer
    Environmental biology of fishes 12 (1985), S. 63-68 
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    ISSN: 1573-5133
    Keywords: Synonymy ; Biogeography ; Diversity ; Phenotypic variation ; Clownfish ; Anemonefish ; Temperature effects ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Captive-bred offspring from a single pair ofAmphiprion frenatus displayed two independent color polymorphisms, one for juvenile stripe pattern and one for adult color. The adult polymorphism encompassed color morphs representingA. frenatus, A. rubrocinctus andA. melanopus. Positive assortative mating occurred, with viable F2 offspring from one pairing. Hybridization has been achieved previously betweenA. melanopus, A. frenatus andA. ephippium, so these four species may be stable polymorphs of a single species, the different morphs selectively maintained in different geographic regions. The extent of polymorphism among marine fishes is poorly understood.
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    Neonatal interactions in pig-tailed macque (M. nemestrina) dyads: Influence on rearing success, infant weight change and behavioral response to reunion with mother (1985)
    Springer
    Primates 26 (1985), S. 45-56 
    Details
    ISSN: 0032-8332
    Keywords: Macaca nemestrina ; Mothe-infant ; Interaction ; Parity ; Attachment ; Failure-to-thrive ; Development ; Reproduction-risk
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This research assessed the significance of variation in dyadic neonatal interaction for subsequent infant development in pig-tailed macaques. Adult females were selected which differed in parity and reproductive risk. The 29 dyads were housed individually to reduce external environmental influences. Large variation was observed in maternal and neonatal behavior, but it was not significantly associated with maternal or infant risk variables and could not identify six unsuccessfully reared pairs. Among the 23 successfully reared dyads, variation in nutritional and behavioral measures hypothesized to be associated with infant growth were found to be independent of neonatal weight gain. These 23 infants were separated from their mothers after 30 days and their responses at reunion were observed. Some infants clung to the mother's ventrum (attached response) while others jumped away quickly (aloof response). Prior dyadic interactions were not significantly associated with this dichotomous response, nor were maternal and most infant variables. These results suggest that dyads at risk for neonate separation when living in captive groups are not necessarily at risk in individual housing conditions. Further, pig-tailed neonates appear unaffected by variations in mother-infant interactions that do not result in separation, but neonatal characteristics may show continuity across development.
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    URL: http://dx.doi.org/10.1007/BF02389046
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    Mucopolysaccharides and collagen in prenatal and postnatal human development (1974)
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    Calcified tissue international 16 (1974), S. 209-217 
    Details
    ISSN: 1432-0827
    Keywords: Mucopolysaccharides ; Collagen ; Calvarium ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Mucopolysaccharides (MPS) and collagen have been analyzed in different types of cartilage and some other tissues at various stages of prenatal and postnatal human development. The concentration of the chondroitin sulfate-type MPS increased from the 38th embryonal day, the 6-sulfate exceeding in amount the 4-sulfate. The increase in collagen concentration was accompanied by a decrease in the proportion of neutral salt-soluble collagen. There was no accumulation of chondroitin sulfates in the calvaria. A maximal concentration of MPS of a low molecular weight occurred in the skin and in the ear pinna after the 10th prenatal week. Postnatally, the MPS-concentration in the iliac crest and in the tibial articular cartilages decreased gradually, the highest values being reached in the newborn; the collagen-concentration showed an approximately reciprocal course.
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    The custom fitting problem and the evolution of developmental systems (1974)
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    Journal of molecular evolution 3 (1974), S. 109-113 
    Details
    ISSN: 1432-1432
    Keywords: “Custom Fitting” ; Development ; Evolution ; Antibody response ; Genetic Redundancy ; Perturbation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary When the complexity of a developmental system evolves to a certain point, appreciable variation must occur in the process. The problem the biologist faces is whether this point constitutes a limit to the evolution of complexity in developmental systems. If not, what mechanisms are employed to cope with the problem ? The problem—essentially one in “custom fitting” of parts, — and the possible solution(s) to it that have evolved are discussed. The antibody producing system appears to be one that “solves” the custom-fitting problem.
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    Growth regulation inCoprinus radiatus (1974)
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    Archives of microbiology 96 (1974), S. 353-364 
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    ISSN: 1432-072X
    Keywords: Coprinus ; Agaricaceae ; Mushroom ; Development ; Growth Regulator ; Stipe Growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Some of the morphological and physiological parameters of stipe growth or elongation inCoprinus radiatus were investigated. During the development of the fruit body the number of cells in a row in the growing portion of the stipe doubled during the development of the button, and again during the phase of rapid stipe elongation. Also during the stage of rapid elongation the cells in the upper 2/3 of the stipe increased 6–8 fold in length. The existence of a growth regulator synthesized in the cap and exerting control over the stipe was demonstrated through decapitation experiments. The cap appears to be required for normal stipe development until the stipe reaches about 1/4 of its final length. Through decapitation and cap-stipe exchanges it was found that the cap produced growth regulator up to the time of autodigestion; however, the stipe responded to the regulator only during a brief period at the onset of elongation.
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    A study of sporophore development in the myxomyceteProtophysarum phloiogenum (1974)
    Springer
    Archives of microbiology 99 (1974), S. 331-344 
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    ISSN: 1432-072X
    Keywords: Myxomycetes ; Ultrastructure ; Development ; Systematics ; Food Vacuoles ; Stalk Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Observations of sporophore development in fresh and glutaraldehydeosmium sequentially-fixed material ofProtophysarum phloiogenum show the following sequence. Small plasmodia cease streaming and round up. Food vacuoles collect in the lower center of the cytoplasmic mass. As the cytoplasm rises the food vacuolar contents are excluded from the plasmalemma and become the stalk core. A continuous, fibrous peridium and stalk tube enclose cytoplasm and stalk core respectively. Capillitial formation just precedes spore cleavage. Sporophore development is marked by autophagic activity and calcium deposition. Stalks of dried herbarium specimens of seven additional species have been examined. A mature stalk morphology very similar toProtophysarum with recognizable remnants of microorganismal food material is seen in all of them. It is thought that this marker is indicative of non-stemonitaceous stalk development.
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    Die Bedeutung von Adenosin-3′,5′-monophosphat für die entwicklung vonAcanthamoeba castellanii (1974)
    Springer
    Archives of microbiology 99 (1974), S. 155-166 
    Details
    ISSN: 1432-072X
    Keywords: cAMP ; Acanthamoeba ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Durch drei verschiedene Methoden wurde in Kulturen vonAcanthamoeba castellanii die stationäre Wachstumsphase, in deren Verlauf sich Trophozoiten zu Cysten entwickeln, induziert: Durch Nahrungsmangel, indem Amöben der logarithmischen Wachstumsphase in ein nährstofffreies Medium überführt wurden, durch Sauerstoffmangel, indem Kulturen zu großer Zelldichte heranwuchsen, und durch Hemmung der mitochondrialen DNS-Synthese, indem Kulturen der logarithmischen Phase mit Äthidiumbromid versetzt wurden. Unabhängig von den Encystierungsbedingungen nimmt die intracelluläre Konzentration von Adenosin-3′,5′-monophosphat (cAMP) bei Verminderung der Zellteilungsrate bis zu Beginn der stationären Wachstumsphase um das 2–3 fache zu. Die Ergebnisse deuten an, daß der Anstieg von intracellulärem cAMP auf eine Erhöhung der Adenylat-Cyclase- und nicht auf eine Verminderung der Phosphodiesterase-Aktivität zurückzuführen ist. Extracelluläres cAMP konnte weder in Kulturen der logarithmischen noch in Kulturen der stationären Phase nachgewiesen werden. Dies ist vermutlich auf die extracellulär vorhandene cAMP-Phosphodiesterase zurückzuführen. Die Tatsache, daß auch durch Theophyllin die stationäre Wachstumsphase und Encystierung induziert werden kann, läßt auf eine Beteiligung von cAMP an den Entwicklungsprozessen, speziell an dem Abbau von Glykogen, schließen.
    Notes: Abstract In cultures ofacanthamoeba castellanii the stationary growth phase in which trophozoites develop to cysts, was induced in three ways: by transferring cells from a logarithmic growing culture into a nutrient-free medium, by growth in nutrient medium to high cell density and by inhibition of the mitochondrial DNA synthesis with ethidium bromide. In all cases, the intracellular concentration of adenosine-3′,5′-monophosphate (cAMP) rises by a factor of two to three from the end of the logarithmic phase to the beginning of the stationary phase. The results show that this rise may be more a consequence of an increased adenylate cyclase activity than of a diminished cAMP phosphodiesterase activity. No extracellular cAMP could be measured in cultures of the logarithmic and stationary growth phase, perhaps because of the extracellular cAMP phosphodiesterase. Because theophylline also induces the stationary phase and encystation, cAMP seems to be of importance for the development ofAcanthamoeba castellanii, especially for the degradation of glycogen.
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    Das Adenosinphosphat-System während Wachstum und Entwicklung von Acanthamoeba castellanii (1974)
    Springer
    Archives of microbiology 101 (1974), S. 391-399 
    Details
    ISSN: 1432-072X
    Keywords: Adenosinephosphate System ; Energy Charge ; Acanthamoeba ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Konzentration von Adenosintri-, Adenosindi- und Adenosinmonophosphat wurde in Acanthamoeba castellanii währed der logarithmischen Wachstumsphase und der stationären Wachstumsphase, in deren Verlauf sich Trophozoiten zu Cysten entwickeln, bestimmt. Der Entwicklungsprozess wurde durch drei verschiedene Methoden hervorgerufen: Durch Wachstum im Nährmedium zu großer Zelldichte, durch Überführen von Amöben der logarithmischen Wachstumsphase in ein nährstoffreies Salzmedium und durch Versetzen logarithmisch wachsender Amöben mit Äthidiumbromid. In allen Fällen wird der Adenosinphosphat-Gehalt in den Zellen im Laufe der Entwicklung um etwa 85% reduziert, wozu besonders die Abnahme des ATP-Gehaltes beiträgt. Die Adenosinphosphat-“energy charge” beträgt in logarithmisch wachsenden Amöben 0,83. Im Laufe der Entwicklung wird sie je nach Encystierungsbedingungen auf unterschiedlichen Werten stabilisiert (zwischen 0,58 und 0,81). Die Möglichkeit eines Zusammenhanges von Konzentrationsveränderungen der Adenosinphosphate und entwicklungsspezifischen Prozessen wird diskutiert.
    Notes: Abstract The concentration of adenosine tri-, adenosine di-, and adenosine monophosphate in cells of Acanthamoeba castellanii was measured during the logarithmic growth phase and the stationary growth phase in which trophozoites were transformed into cysts. This developmental process was induced in three ways: by growth in nutrient medium to high cell density, by transferring cells in the logarithmic phase into a nutrient-free medium, and by mixing logarithmically growing cells with ethidium bromide. In all cases, encystment is accompanied with a reduction of total adenosine phosphate content to about 85%, mainly because of a depletion of cellular ATP. The value of the adenosine phosphate energy charge in logarithmically growing amoebae is 0.83. During development the energy charge becomes stabilized at different values (between 0.58 and 0.81), characteristic to the mode of encystation. A possible functional relationship between changes of the adenosine phosphate concentration and developmental processes of the amoeba is discussed.
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    Structure and development of the tracheal organ in the mesothoracic leg of the cricket Teleogryllus commodus (Walker) (1974)
    Springer
    Cell & tissue research 147 (1974), S. 325-334 
    Details
    ISSN: 1432-0878
    Keywords: Chordotonal (Tracheal) organ ; Teleogryllus commodus (Orthoptera) ; Hearing ; Development ; Structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The tracheal organ of the mesothoracic tibia of Teleogryllus is located in a corresponding position to the tympanal organ of the prothoracic tibia. The mesothoracic organ contains an average of only 12 scolopidia, the location of which corresponds to that of the proximal group A and proximal main group in the prothoracid tympanal organ. There are no scolopidia corresponding to the distal group of the tympanal organ. The variability in number of scolopidia is much greater in the mesothoracic organ than in the prothoracic organ. The adult tracheal system of the mesothoracic leg resembles the early nymphal tracheal system in both pro- and meso-thoracic legs. The development of the tracheal organ is usually complete by the sixth instar. The mesothoracic tracheal organ of the adult is broadly equivalent to the prothoracic tympanal organ of a fifth instar animal.
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    Ultrastructure of synaptosomes from one-day old and adult rat brain stem (1974)
    Springer
    Cell & tissue research 148 (1974), S. 535-550 
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    ISSN: 1432-0878
    Keywords: Synaptosomes ; Rat brain stem ; Synaptogenesis ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure and protein content of the five subfractions of the crude mitochondrial fraction from the brain stem of the 1-day old and adult rat was examined. The morphological composition of the subfractions after fixation in glutaraldehyde and osmiumtetroxide in the adult rat brain stem resembled that previously reported for the whole brain; synaptosomes sedimented in a sucrose gradient in subfractions C and D. In the 1-day old rat, mature synaptosomes were found in subfractions A, B, C and D; E contained mainly free mitochondria. 80–95% of the processes in the adult and 10–30% in the 1-day old rat contained synaptic vesicles which were of four types: (1) small agranular vesicles (2) large dense core vesicles (3) large agranular vesicles (4) coated vesicles. Pre- and postsynaptic membrane thickenings were demonstrated in many nerve-ending particles. In the subfractions of the 1-day old rat the protein content was one half and the distribution resembled that in the adult. Evidently nerve endings develop faster in the brain stem than in cortical areas; a serotoninor adrenergic origin of the early synaptosomes is suggested.
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    Acinar ultrastructure of the submandibular gland of Mus musculus during embryonic development (1974)
    Springer
    Cell & tissue research 150 (1974), S. 425-442 
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    ISSN: 1432-0878
    Keywords: Glandula submandibularis (Mouse) ; Acinar ultrastructure ; Cell types ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the submandibular gland of the mouse was studied by means of electron microscopy, from the 14th day of gestation up to birth. In the first two days the acini are solid and their cells contain polyribosomes and a few lamellae of endoplasmic reticulum. Beginning with the 16th day secretory granules appear and rapidly fill an increasing number of cells. The different electron density of the granules makes it possible to distinguish 1. two types of granules, dense and pale, and sometimes intermediate ones, 2. “polymorphic” granules. The latter consists of electron dense and electron pale parts combined in different configurations. The possible significance of the various types of granules is discussed.
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    Studies on the juxtaglomerular apparatus (1974)
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    Cell & tissue research 151 (1974), S. 433-456 
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    ISSN: 1432-0878
    Keywords: Juxtaglomerular apparatus (Rat) ; Development ; Renin ; Pools ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die perinatale Entwicklung des juxtaglomerulären Apparates, insbesondere das Verhalten der epitheloiden Zellen wurde an 18 trächtigen Ratten and 65 Embryonen bzw. Jungtieren elektronenmikroskopisch untersucht. Parallel dazu wurde die Reninkonzentration bzw. der Reningehalt bestimmt. Spezifische Sekretgranula finden sich erstmals am 18. Tag der Fetalzeit, und zwar in den epitheloiden Zellen des juxtaglomerulären Apparates juxtamedullärer Nephrone. Die Granula machen einen Struktur- und wahrscheinlich auch Funktionswandel durch, der eine Einteilung in drei verschiedene Granulatypen nahelegt. Diesen drei Typen spezifischer (reninhaltiger) Sekretgranula werden die Lysosomen als unspezifische Einschlüsse der epitheloiden Zellen gegenübergestellt. Im einzelnen kommt es während der perinatalen Phase in den fetalen Epitheloidzellen zuerst, d.h. pränatal, zu einer Hypertrophie des rauhwandigen endoplasmatischen Retikulums und des Golgi-Apparates. Hierin sehen die Autoren einen Hinweis auf eine erhöhte Proteinsynthese mit entsprechender Zunahme der Transport- und Konzentrationsvorgänge. Nach der Geburt findet sich dann auch eine deutliche Zunahme der Sekretgranula vom Typ III, die als reife Reningranula (mature granules) angesehen werden. Die bisher noch nicht beschriebenen kleinen Sekretgranula vom Typ I dagegen kommen in weniger entwickelten Epitheloidzellen häufiger vor. Bestimmungen der Reninverteilung zwischen Zytoplasma und den durch Differential-zentrifugation gewonnenen Granula-Fraktionen ergeben auffallende Parallelen zu den morphologischen Befunden. Diese sprechen im allgemeinen dafür, daß “freies Renin” im Ergasto-plasma und “gebundenes Renin” in den Sekretgranula vorliegt. Mit zunehmendem Alter scheint es außerdem — parallel zur relativen Abnahme des Ergastoplasmas und Zunahme der reifen Reningranula — zu einer Verminderung des extragranulären zugunsten des granulär gebundenen Renins zu kommen.
    Notes: Summary The perinatal development of the Juxtaglomerular apparatus (JGA), with particular reference to the epithelioid cells, was studied. Electron microscopic studies were carried out on 18 gravid rats and 65 embryos with corresponding determinations of renin concentration and the renin contents by bio-assay. Specific secretory granules of the epithelioid cells of the JGA of juxtamedullary nephrons are first observed on the 18th day of gestation. The classification into three types of secretory granules suggests that they undergo a structural and probably also a functional transformation. All three types of secretory granule may be regarded as specific, renin-containing, cytoplasmic organelles. During the last days of gestation, the rough-surfaced endoplasmic reticulum and the Golgi apparatus become hypertrophied in epithelioid cells, indicating an increased protein synthesis as well as transport and concentration processes. After birth, there is a definite increase in the number of Type III secretory granules-which may be regarded as mature granules. The small Type I secretory granulesnot previously described-are found more frequently in the immature epithelioid cells. Determinations of the renin distribution in the plasma and in fractions of cytoplasmic constituents (total homogenate, secretory granules) prepared by differential centrifugation showed striking congruence with the morphological findings. It is generally assumed that “soluble renin” occurs in the endoplasmic reticulum and “bound renin” in secretory granules. A shift from extragranular to granular (bound) renin, occurs with increasing age, having its morphological equivalent in the relative decrease of the endoplasmic reticulum and increase in mature secretory granules.
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    The differentiation of intrafusal fibre types in rat muscle spindles after motor denervation (1974)
    Springer
    Cell & tissue research 153 (1974), S. 115-136 
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    ISSN: 1432-0878
    Keywords: Muscle spindles ; Intrafusal fibre types ; Development ; De-efferentation ; Utrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Hind limb muscles were de-efferented in 19 new-born rats by removal of the lumbosacral spinal cord, with preservation of spinal ganglia and their peripheral branches. The juxtaequatorial and polar zones of muscle spindles were studied in different leg muscles 3 to 9 weeks after the operation in order to establish whether intrafusal fibre types would become differentiated after permanent motor denervation. De-efferented intrafusal fibres developed into distinct ultrastructural fibre types similar to those found in control muscles. The nuclear bag type had confluent myofibrils with ill-defined M lines and relatively few mitochondria. The nuclear chain type had discrete myofibrils with prominent M lines, numerous large mitochondria and a more developed sarcotubular system. The fibre type characteristics were sometimes blurred by disarranged cross striation, but they were clearly discernible in 59 out of 69 de-efferented fibres of 31 spindles investigated in the electron microscope. A sample of 220 de-efferented spindles from leg muscles of 6 rats was examined in the light microscope on transverse sections stained for ATPase activity. The difference in the ATPase activity among intrafusal fibre types was marked in about 70% spindles; in contrast to this, no distinct fibre types could be discerned in the population of extrafusal fibres which were stained rather uniformly. In de—efferented spindles-as in normal control spindlesnuclear chain fibres always exhibited high ATPase activity, whereas one of the nuclear bag fibres had low ATPase and the other either low or medium to high ATPase activity. However, the ATPase activity of de-efferented muscles was generally lower than that of normal muscles. It can be concluded that intrafusal fibres do acquire their fibre type characteristics after fusimotor denervation despite complete deprivation of nerve impulse activity during the postnatal period when intrafusal fibre types differentiate in normal spindles.
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    Structure, development and function of the protonephridia in trochophores of Pomatoceros triqueter (Annelida, Polychaeta, Sedentaria) (1974)
    Springer
    Cell & tissue research 156 (1974), S. 21-33 
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    ISSN: 1432-0878
    Keywords: Protonephridium ; Pomatoceros triqueter (Annelida, Polychaeta, Sedenta-ria) ; Terminal cell ; Channel cell ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary During the development of the intermediate and late gastrula of Pomatoceros triqueter, the terminal and channel cells grow towards each other and form the protonephridium. They interdigitate through lateral microvilli. The junctions between the cells form filtration clefts, which are bridged by fibrils.
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    Ultrastructure of the lamina propria in the ovine seminiferous tubule (1974)
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    Cell & tissue research 150 (1974), S. 481-492 
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    ISSN: 1432-0878
    Keywords: Seminiferous tubule, ovine ; Lamina propria ; Development ; Endocrine factors ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the lamina propria in the ovine seminiferous tubule was studied from 54 days (postcoitum) fetuses up to sexual maturity. In young animals (aged about two months) the effect of hypophysectomy and/or hormones was also analyzed. Initially, large areas of the lamina propria already show signs of morphological differentiation. The non cellular component is a single or sometimes double lamella. Outwardly, the cellular component is represented by rounded connective tissue cells or by elongated cells, exhibiting 80 Å filaments in the cytoplasm and arranged in 3 to 4 layers. By the first week after birth, the non cellular component is formed by 8 to 10 lamellae and the cellular component shows typical contractile cells, the fibroblasts being now located only in the periphery. Basically, the same aspect is found in the adult ram, thus differing from the more extensively studied prototypes of lamina propria architecture of rodents or primates. In as much as the sheep lamina propria differentiates precociously, probably induced by fetal testicular hormones, it is relatively insensitive to hypophysectomy or hormonal substitution. Hypophysectomy and cyproterone acetate administration cause intracytoplasmic lipid deposition in the contractile cells, the other components being not changed. Some questions are raised concerning the role of this peculiar lamina propria in the function of the blood-testis barrier.
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    Development of secondary lamellae of the gills of the trout, Salmo gairdneri (Richardson) (1974)
    Springer
    Cell & tissue research 151 (1974), S. 509-523 
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    ISSN: 1432-0878
    Keywords: Gill ; Trout ; Secondary lamellae ; Development ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A light and electron microscope study of secondary lamellae of trout developing at 10° C is described. Collagen is secreted by mesenchyme cells in the connective tissue of the developing gill filament. This becomes enclosed in infoldings around the peripheries of mesenchyme cells. These cells become aligned in a single plane within folds of basement membrane and epithelium. The basement membrane of opposite sides of the fold becomes connected by a thick layer of collagen. Blood spaces form around the margin of the fold, connecting afferent and efferent filament blood vessels. Endothelial granules form in cells lining the outer border of the marginal channel when blood flow begins. Rows of pillar cells separate from the proximal layer of mesenchyme cells as the secondary lamellae develops further. New secondary lamellae are added at the filament tips. At 28 days, the basement membrane consists of 2 layers, a fine fibrous layer and 5–15 orthogonally arranged layers of collagen fibres. By 31 days, the collagen is arranged at random and the layer is thinner. A clear layer is also present by 67 days. A multilayered epithelium containing mucous and chloride cells is present at 28 days. By 102 days, the secondary lamellae are covered by 2 layers of epithelial cells only. Chloride cells are present in much greater numbers in developing gills than in the adult.
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    The ultrastructure of the human fetal pineal gland (1974)
    Springer
    Cell & tissue research 152 (1974), S. 13-30 
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    ISSN: 1432-0878
    Keywords: Human fetal pineal gland ; Development ; Secretion ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the pineal gland of 18 human fetuses (crown-rump lengths 30–178 mm) was investigated. The pineal gland exhibits a pyramidal shape and consists of an anterior and posterior lobe. Only one parenchymal cell type, the pinealocyte, was observed. Few neuroblasts were seen between the pinealocytes and in the extended perivascular space. The pinealocytes possess all the organelles necessary for hormone synthesis. No specific secretory granule could be observed. The organ is abundantly vascularized and richly innervated. The morphology of the capillaries indicates the existence of a blood-brain barrier. The ultrastructure of the human fetal pineal gland suggests that the gland has a secretory function in early intrauterine life.
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    URL: http://dx.doi.org/10.1007/BF00224208
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    Structure and development of the auditory system in the prothoracic leg of the cricket Teleogryllus commodus (walker) (1974)
    Springer
    Cell & tissue research 147 (1974), S. 313-324 
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    ISSN: 1432-0878
    Keywords: Chordotonal organ ; Teleogryllus commodus ; Hearing ; Structure ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The anatomical development of the tympanal organ, the tracheal system and the tympana of Teleogryllus commodus is described. The tympanal organ is undifferentiated until instar 3 when the first scolopales appear. The organ develops in a proximo-distal direction but the more distal groups begin to form before the proximal groups are complete. All groups of scolopidia are represented in instar 7 but numbers of scolopidia continue to increase until the adult stage. Scolopales and scolopale cells are first formed at less than adult size and increase in size during subsequent instars. The subgenual organ is present in instar 1 and is complete in instar 4. The posterior and anterior tympanal trachease develop respectively from the tracheal trunk and tracheal branch, which are present from instar 2. These remain as simple, unconnected tubes until instar 7 and begin to show the adult form during instars 8 and 9, finally enlarging in conjunction with the tympana at the last two moults. The tympana first appear as hairless areas of cuticle in the larval stages: the posterior tympanum in instar 8 and anterior tympanum in instar 10, but the translucent appearance of the adult tympana is not present before the final moult.
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    Osteocyte types in the developing mouse calvarium (1973)
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    Calcified tissue international 12 (1973), S. 259-279 
    Details
    ISSN: 1432-0827
    Keywords: Osteocyte ; Calvarium ; Histology ; Development ; Calcium ; Phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Des cartes tissulaires ainsi que les caractéristiques et propriétés cellularires ont été relevées au cours d'une étude de microscopie optique du développement de la calotte cranienne de souris, avant la naissance, jusqu'au 26ème jour. Les population d'ostéocytes de moitiés droite et gauche de ces calottes sont semblables, mais décroissent avec le temps dans un volume donné. De petites plages limitées de matrice osseuse se colorent pour le phosphate (ou carbonate) de façon plus nette que la matrice environnante, qui se colore légèrement après coupe. Les divers types ostéocytaires se distinguent par les réactions histochimiques du calcium et du phosphate, qui sont associés dans les cellules osseuses de façon complexe, variant dans le temps et la localisation. Ces deux constituants ne sont pas toujours présent dans les cellules des diverses régions, ou dans la même localisation dans un type cellulaire donné. En tenant compte des changements visible dans les divers types cellulaires avec le temps, dans des régions données, une hypothèse de “charge” et “décharge” cellulaire est émise.
    Abstract: Zusammenfassung Anläßlich einer mikroskopischen Studie über die Entwicklung des Mäuse-Calvariums von der Pränatalperiode bis zu 26 Tagen nach der Geburt wurden auch die Gewebetopographie sowie die Charakteristica und Eigenschaften der Zellen aufgezeichnet. Die Osteocyten-populationen in der linken und rechten Hälfte des Calvariums waren sich gleich, nahmen jedoch bei einem gegebenen Volumen mit der Zeit ab. Kleine isolierte Stellen von Knochen-matrix konnten leichter auf Ph sphat (oder Carbonat) angefärbt werden, als die umgebende Matrix, welche sich wohl am Schnitt, nicht aber am ganzen Stück färben ließ. Die verschiedenen Typen von Osteocyten wurden aufgrund histochemischer Calcium- und Phosphat-reaktionen bestimmt. Calcium und Phosphat waren innerhalb der Knochenzellen auf komplexe Art miteinander verbunden, die je nach Zeit und Lagerung unterschiedlich war. Zellen in abgetrennten Bereichen enthielten nicht immer Calcium und Phosphat und beide waren bei einer bestimmten Zellenart auch nicht immer am gleichen Ort abgelagert. Aufgrund der an ausgewählten Stellen beobachteten, zeitlich bedingten Veränderungen innerhalb der verschiedenen Zelltypen wird vorgeschlagen, daß es sich dabei um eine Sequenz von “Ladung” und “Entladung” der Zellen handelt.
    Notes: Abstract Tissue maps, and cell characteristics and properties were recorded in a study under the optical microscope of the development of the mouse calvarium from pre-natal to 26 days. Osteocyte populations in left and right halves of the calvarium were similar, but decreased with time for a given volume. Small isolated areas of bone matrix stained for phosphate (or carbonate) in a more readily available form from that in the surrounding matrix, which could be stained after sectioning but failed to stain in bulk. Osteocyte types were defined on the basis of histochemical methods for calcium and phosphate, which were associated inside bone cells in a complex manner, varying with time and position. The calcium and phosphate were not always present within the cell in discrete regions and were not always present in the same place in a given cell type. On the basis of a study of changes in cell types with time in selected sites a sequence of “loading” and “unloading” is proposed.
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    A comparison of the fine structure of thoracic and abdominal interganglionic connectives in the newly hatched and adult stick insect, Carausius morosus Br. (1973)
    Springer
    Cell & tissue research 145 (1973), S. 299-309 
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    ISSN: 1432-0878
    Keywords: Nervous system ; Stick insect ; Blood-brain barrier ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fat body sheath which surrounds the ventral nerve cord of the adult stick insect, Carausius morosus, is absent in the hatchling. Since the haemolymph sodium ion compositions of the two stages are similar, it is suggested that the fat body sheath is not a site of a blood-brain barrier dealing with extra-axonal regulation of sodium. Similarities of ultrastructure in connectives of adults and hatchlings are demonstrated, and tight junctions are shown to occur in perineural cells of both stages. The possible significance of this to the blood-brain barrier of this insect is discussed.
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    Studies on the effect of denervation in developing muscle (1973)
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    Cell & tissue research 147 (1973), S. 75-85 
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    ISSN: 1432-0878
    Keywords: Skeletal muscle ; Denervation ; Development ; Fiber types, myofibrils ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural diversification of muscle fibers, with regard particularly to myofibrillar changes, has been investigated in the fast-twitch extensor digitorum longus (EDL) and the slow-twitch soleus muscles of the rat during fetal and postnatal development in the presence and in the absence of motor innervation. The band pattern and the shape of the myofibrils were uniform in fetal and neonatal muscle fibers and underwent differential changes during the first weeks after birth, concomitantly with fiber type specialization. The most evident variations in myofibrillar structure arising in this period concern the thickness of the Z band and the arrangement of the myofibrils. Myofibril formation was at first not impaired by denervation of rat muscles performed in utero and, although focal disintegration of myofibrils and detachment and loss of orientation of filaments became apparent by one week, atrophic muscle fibers with well-organized myofibrils could be seen as late as 2 months after birth. However, denervated muscle fibers of EDL and soleus did not display any significant and consistent difference in myofibrillar band pattern and shape. No variation in mitochondrial content and sarcoplasmic reticulum development was likewise seen in muscle fibers of EDL and soleus after fetal denervation. The findings emphasize the importance of neuromuscular interactions in muscle differentiation.
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    Development of muscle spindles deprived of fusimotor innervation (1973)
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    Cell & tissue research 144 (1973), S. 435-452 
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    ISSN: 1432-0878
    Keywords: Muscle spindles ; Intrafusal fibre types ; Development ; Deefferentation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Muscle spindles of limb muscles were deefferented in neonatal rats by sectioning ventral roots or by removal of the lumbosacral spinal cord. Ten to 56 days after the operation, muscle spindles were examined in the medial gastrocnemius, extensor digitorum longus and soleus muscles. The differentiation of muscle spindles was not affected by deefferentation. The number of spindles in the investigated muscles was not reduced. Intrafusal fibres increased in number from two at birth to four per spindle on the average, as in normal muscles. The characteristic ultrastructural distinctions of nuclear bag and nuclear chain fibres developed as under normal conditions. However, intrafusal fibres atrophied slowly after fusimotor denervation, their polar zones becoming reduced in diameter by about 25% in comparison with control fibre diameters. Spindle capsules, on the other hand, increased in size and attained diameters comparable with normal spindles, appearing even somewhat distended. As intrafusal fibres degenerate after complete denervation at birth (Zelená, 1957), but differentiate in the absence of fusimotor innervation, it can be concluded that sensory nerve terminals induce and support their development. It is assumed that the morphogenetic influence of sensory terminals is mediated by release and uptake of a trophic substance at the synaptic junction. The occurrence of light and dense core vesicles in the sensory terminals and of coated invaginations and vesicles at both the axonal and plasma membrane speak in favour of such a possibility.
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    Synaptic junction development in the spinal cord of an amphibian embryo: An electron microscope study (1973)
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    Cell & tissue research 137 (1973), S. 251-269 
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    ISSN: 1432-0878
    Keywords: Synapse ; Development ; Spinal cord ; Amphibian
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An electron microscopical study has been made of the cervical spinal cord of Xenopus laevis embryos, from the time that the neural tube closes until the larvae were hatched and could swim. Sections of the whole cord were searched for intercellular junctions during this period. Two nonsynaptic types were found, the first were widely distributed puncta adherentia, the second were rare and similar to “gap” junctions. Membrane specializations with synaptic vesicles were first found when the neural folds had fused; “membrane-vesicle clusters” which looked like the presynaptic half of a synaptic junction were present, together with synaptic junctions lacking any postsynaptic membrane thickening or cytoplasm density. About four hours later, mature synaptic junctions with full thickening of the postsynaptic membrane, dense cytoplasm and striated or dense material in the synaptic cleft were present. Presynaptic mitochondria, dense-cored and flattened vesicles, fibre to fibre and fibre to cell body synapses were present from the first, as were synapses onto very fine dendrites which might be filopodia from dendritic growth cones. Synaptogenesis may start with the accumulation of vesicles in dense cytoplasm near a thickened cell membrane; the postsynaptic element becomes associated with this “membrane-vesicle cluster” and matures by increasing cleft and cytoplasmic density, and by membrane thickening.
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    The development of a hypothalamic monoaminergic system for the regulation of the pars intermedia activity in Xenopus laevis (1973)
    Springer
    Cell & tissue research 143 (1973), S. 229-238 
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    ISSN: 1432-0878
    Keywords: Hypothalamo-hypophysial system ; Development ; Monoamines ; Colour change ; Fluorescence microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In Xenopus laevis the development of hypothalamic monoaminergic cells was studied in relation to adaptation to background colour. The first melanophores appear at stage 33/34 (normal table of Nieuwkoop and Faber, 1956), gradually increasing in number. The melanine granules are dispersed throughout the cell, irrespective of the background colour. The dispersion apparently is caused by MSH released by the developing pars intermedia cells. Between stage 39 and stage 41, larvae placed on a white background changed colour from black to white due to aggregation of the melanine granules within the melanophores. With Falck's method for demonstrating monoamines, a small number of fluorescent cells was observed in the hypothalamus simultaneously with the first background-dependent colour change. These cells were arranged in a paired nucleus, bordering the third ventricle. Initially, the nucleus extends from 50 microns behind the optic chiasma to the lateral dilatations of the third ventricle; 8–10 hours later, similar cells were also found at the lateral dilatations and in the dorso-lateral part of the infundibular lobe. The cells have apical processes protruding in the ventricular lumen. Fluorescent axons, originating from the cells, were occasionally observed. Considering the above-mentioned results in combination with the electron microscopical data of Nyholm (1972), it is concluded that the MSH producing cells are under monoaminergic nervous control from the beginning of background colour adaptation.
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    Détection par immunofluorescence des cellules corticotropes et mélanotropes dans l'hypophyse de la grenouille, Rana temporaria L., au cours du développément (1973)
    Springer
    Cell & tissue research 142 (1973), S. 571-580 
    Details
    ISSN: 1432-0878
    Keywords: Hypophysis ; Rana temporaria ; Development ; Corticotropin cells, melanotropin cells ; Immunofluorescence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary During the embryonic and larval developmental stages of the frog, Rana temporaria L, anti-β 1–24, α 17–39 corticotropine, α and β MSH antibodies were used to define, with immunofluorescence technique, the appearence of corticotropic and melanotropic cells. A very small number of fluorescent corticotropic cells appears for the first time during the embryonic stage (10 mm), just before the differentiation of the pars intermedia. The cells are small, their large nucleus is surrounded by a fine rim of fluorescent cytoplasm. During premetamorphic stage, the anti-ACTH antibodies (anti-β 1–24 and anti-α 17–39 corticotropine) reveal more fluorescent cells in the whole pars distalis. The pars intermedia cells can also be visualized by both antisera. At the end of prometamorphosis and during climax the corticotropic cells show a more precise localization. As in adult frog pars distalis, they are concentrated in the rostral half of the lobe. With the same technique anti-α and β MSH antibodies reveal only the cells of the pars intermedia. No other cell type of the pars distalis reacts with these antibodies. This technique has the advantage to show that the ACTH and the MSH cells appear very early during the embryonic life.
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    Effect of hydrocortisone on the extra-adrenal intensely fluorescent chromaffin and non-chromaffin cells in stretch preparations of the newborn rat (1973)
    Springer
    Cell & tissue research 146 (1973), S. 565-578 
    Details
    ISSN: 1432-0878
    Keywords: Sympathetic neurons ; Chromaffin cells ; SIP cells (Newborn rat) ; Development ; Administration of hydrocortisone ; Stretch preparations ; Fluorescence microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Air-dried stretch preparations were used to study adrenergic nerve fibres and catecholamine-containing cells with the formaldehyde-induced fluorescence method in the abdominal tissue block containing the para-aortic paraganglia, in the neurovascular structures of the cervical region including the carotid body, in the bladder, in the ileum, in the mesentery, in the vagus nerve and in the sympathetic ganglia of 5- or 15-day-old rats. The adrenergic nerves and the catecholamine-containing cells were well preserved and showed little or no diffusion of amines. While most intensely fluorescent cells of the main para-aortic body disappeared during the first two postnatal weeks, some such cells survived and they showed long, slender fluorescent processes. Administration of 20 mg/kg of hydrocortisone acetate daily for 5 days after birth caused a striking increase in the number and size of the clusters of the intensely fluorescent cells in the organ of Zuckerkandl, in the sympathetic ganglia and in the bladder, as well as an increase in the fluorescence intensity of the carotid body. In rats treated with hydrocortisone for 5 days and left to recover for 10 days an increased fluorescence was still observed. However, in the organ of Zuckerkandl the intensely fluorescent cells of hydrocortisone-treated 15-day-old rats showed less processes than those of the control rats of the same age.
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    URL: http://dx.doi.org/10.1007/BF02347184
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  • 90
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    Unique sensory endings in rat muscle spindles (1973)
    Springer
    Cell & tissue research 136 (1973), S. 511-520 
    Details
    ISSN: 1432-0878
    Keywords: Muscle spindle ; Sensory ending ; Rat ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A fine structural study of sternothyroid muscle spindles of young adult rat demonstrates the rare occurrence of unique nerve endings. These endings are situated in the juxta-equatorial region of nuclear-bag fibers, adjacent to the annulo-spiral sensory endings. They consist of a bundle of terminal axons less than 0.3 μ in diameter and appear to be disposed nearly longitudinally to the axis of the intrafusal fibers. Whereas, the annulo-spiral endings consist of a single axon, coiling around the intrafusal fibers. Transverse sections of these muscle spindles reveal these unique endings scattered around the muscle fibers, fitting into depressions on their surface. The innermost axons directly face the muscle surface and are separated by a narrow gap less than 200 Å in width. No Schwann cell process appears to be associated with these endings. From their unique multi-axonal composition, these endings are termed “bundled endings”. Investigations of developing muscle spindles show the occasional presence of a similar multi-axonal composition of sensory endings in perinatal rats. It is suggested that “bundled endings” are sensory in nature, carrying an immature feature over to adult life.
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    URL: http://dx.doi.org/10.1007/BF00307367
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  • 91
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    An electron microscopic study of macroglia and microglia in the lateral funiculus of the developing spinal cord in the fetal monkey (1973)
    Springer
    Cell & tissue research 140 (1973), S. 145-167 
    Details
    ISSN: 1432-0878
    Keywords: Macroglia ; Microglia ; Spinal Cord ; Monkey ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An electron-microscopic study has been made of the glial cells in the developing lateral funiculus of the cervical spinal cord in fetal rhesus monkeys. The various macroglial cell types, their precursor cells, and microglia are discussed in detail. An astrocytic lineage is proposed in which glioblasts present in the lateral funiculus give rise to astroblasts that then develop into mature astrocytes. Oligoblasts apparently migrate into the lateral funiculus as such and develop into active oligocytes. The active oligocytes become most predominant during the initial stages of myelinogenesis and are in direct continuity with developing myelin. The active oligocytes develop into mature oligocytes after myelination is completed. Microglia cells are present throughout development as three forms; resting microglia, globose microglia, and active microglia. The globose and active microglia predominates at specific times early in development when degeneration of apparent neuronal processes is taking place. The microglia cells are characterized by dense nuclear chromatin clumps, lipid inclusion bodies, dense vesicles, and, often, intracellular debris.
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    URL: http://dx.doi.org/10.1007/BF00306691
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  • 92
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    The development of synapses in vitro between previously dissociated chick spinal cord neurons (1973)
    Springer
    Cell & tissue research 140 (1973), S. 203-216 
    Details
    ISSN: 1432-0878
    Keywords: Synapses ; Development ; Chick embryo ; Cell culture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The formation and development of synaptic contacts between dissociated chick spinal cord neurons has been investigated. By the 6th day in vitro “immature” profiles with few vesicles were observed. By 14–18 days “mature” types with numerous vesicles were found, indistinguishable from those of newly hatched chick spinal cord. After this period degeneration occurred, and was especially marked in the post-synaptic element. Such degeneration could be postponed by the addition of small numbers of somatic muscle cells. The Kanaseki and Kadota (1969) technique was applied to the study of coated vesicles at various stages of synaptic development.
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    URL: http://dx.doi.org/10.1007/BF00306695
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    Effects of colchicine and vinblastine on neurotubules of the sciatic nerve and cholinesterases in the developing myoneural junction of the rat (1973)
    Springer
    Cell & tissue research 142 (1973), S. 193-204 
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    ISSN: 1432-0878
    Keywords: Neuromuscular junction ; Development ; Cholinesterases ; Axonal transport, Neurotubules, Colchicine, Vinblastine ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Colchicine (0.1 M) or vinblastine (0.01 M) was locally applied on the sciatic nerves of newborn rats. Both colchicine and vinblastine caused reversible disappearance of axonal neurotubules and appearance of increased amounts of neurofilaments at the site of application. Subsequent morphogenesis of myoneural junctions in the tibialis anterior muscle was studied after histochemical demonstration of acetylcholinesterase (AChE; E.C. 3.1.1.7) and non-specific cholinesterase (Ns. ChE; E.C. 3.1.1.8) activity in the myoneural area. Development of the postsynaptic muscle plasma membrane of the myoneural junction was arrested in the ipsilateral, but not in the contralateral control side, for a period of about three weeks following treatment with the test substances. After this delay the myoneural morphogenesis continued normally and neurotubules were seen in the axoplasm. Since disruption of neurotubules is likely to cause blockage of the intratubular axoplasmic transport system, it seems possible that the neurotrophic influence responsible for the development of the postsynaptic muscle membrane is mediated through a secretory product transported along axons intratubularly to the nerve endings.
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    URL: http://dx.doi.org/10.1007/BF00307032
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    A light and electron microscopic study of the pre- and postnatal development and secretory differentiation of the pars tuberalis of the rat hypophysis (1973)
    Springer
    Cell & tissue research 142 (1973), S. 347-365 
    Details
    ISSN: 1432-0878
    Keywords: Pars tuberalis ; Rat ; Development ; Secretion ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the pars tuberalis was studied in the rat fetus from 13 days of gestation to 6 weeks after birth. After the closure of Rathke's pouch, the pars tuberalis anlage is clearly distinguishable from the anlagen of the partes intermedia and distalis. It comprises the entire basal portion of the adenohypophysial anlage; the limit between the anlagen of the pars tuberalis and the pars distalis is defined by Atwell's recess, i.e. the pathway taken by the hypophysial vessels coming from the vascular plexus of the median eminence. At 14 days the pars tuberalis cells are characterized by the presence of glycogen which persists in the adult. Their secretory differentiation (elaboration of granules with a diameter of 100–120 nm) is obvious at 15 days of gestation. It therefore, clearly precedes that of the other hypophysial cell types. Its functional differentiation takes place well before its adhesion to the primary vascular plexus of the portal system. Cystic formations appear just before birth in the pars tuberalis, much later than those of the pars distalis. These observations on the development of the pars tuberalis, together with previous observations on the adult PT in various species, showing that the specific glandular cells of the pars tuberalis are cytologically different from all known adenohypophysial cell types, seem to indicate a specific endocrine function of this lobe.
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    URL: http://dx.doi.org/10.1007/BF00307357
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    Tetracycline effects on statolith and nematocyst differentiation inAurelia (1972)
    Springer
    Calcified tissue international 9 (1972), S. 122-130 
    Details
    ISSN: 1432-0827
    Keywords: Tetracycline ; Development ; Calcification ; Statolith ; Nematocysts ; Aurelia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé L'effet de la tétracycline HCl sur la synthèse de statolithes de sulfate de calcium chezAurelia a été étudié. La tétracycline inhibe la synthèse de statolithes et nématocystes à un stade précoce de strobilation. La tétracycline, cependant, n'est pas incorporée dans les statolithes ou nématocystes en formation. Comme la tétracycline ne se combine pas avec le calcium des statolithes de sulfate de calcium dihydraté d'Aurelia, l'explication des effets d'inhibition sur la différenciation de statolithes et nématocystes ne semble pas liée avec un facteur en rapport avec l'incorporation. Des étudesin vitro de quatre systèmes inorganiques de calcium et de tétracycline montrent que le sulfate de calcium dihydraté (gypse) n'incorpore pas la tétracycline: il en est de même de son équivalent isostructural, le phosphate de calcium hydrogéné dihydraté (brushite). Le carbonate de calcium et le phosphate de calcium (apatite) incorpore la tétracycline. L'explication des différences de comportement du calcium peut être liée à la structure cristalline des composés respectifs, et, en particulier, au fait que l'ion Ca est prêt ou non à réagir avec la tétracycline.
    Abstract: Zusammenfassung Es wird über die Wirkung von Tetracyclinchlorhydrat auf die Synthese von Calciumsulfat-Statolithen beiAurelia berichtet. Wird das Tetracyclin in einem Frühstadium der Strobilation verabreicht, so hemmt es die Synthese der Statolithen und der Nematocysten. Das Tetracyclin wird jedoch nicht in die sich bildenden Statolithen oder Nematocysten eingebaut. Da sich das Tetracyclin nicht mit dem Calcium der Calciumsulfatdihydrat-Statolithen derAurelia verbindet, so kann dessen Hemmwirkung auf die Statolithen und die sich differenzierenden Nematocysten offenbar nicht mit einem einbaubedingten Faktor erklärt werden. Untersuchunge, die in vitro mit vier verschiedenen anorganischen Calciumsalzen und Tetracyclin ausgeführt wurden, zeigten, daß weder Calciumsulfatdihydrat (Gips), noch dessen isotrukturelles Aequivalent Calciumhydrogenphosphatdihydrat (Bruschit) Tetracyclin einbauen. Dagegen inkorporieren Calciumcarbonat und Calciumphosphat (Apatit) das Tetracyclin. Die Erklärung für dieses unterschiedliche Verhalten der Calciumsalze findet sich in der Kristallstruktur der betreffenden Verbindungen, d.h. es hängt davon ab, ob das Calciumion ür die Reaktion mit Tetracyclin leicht verfügbar ist.
    Notes: Abstract The effect of tetracycline HCl on synthesis of calcium sulphate statoliths inAurelia is reported. Tetracycline inhibits synthesis of statoliths and nematocysts when administered at an early stage of strobilation. The tetracycline, however, is not incorporated into the developing statoliths or nematocysts. As the tetracycline does not combine with the calcium of the calcium sulfate dihydrate statoliths ofAurelia, an explanation for its inhibitory effects on statoliths and nematocyst differentiation apparently does not rest with an incorporation-related factor. In vitro studies of four inorganic calcium systems and tetracycline revealed that calcium sulfate dihydrate (gypsum) did not incorporate tetracycline nor did its isostructural equivalent, calcium hydrogen phosphate dihydrate (brushite). Calcium carbonate and calcium phosphate (apatite) did incorporate tetracycline. The explanation for these different behaviors of calcium can be found in the crystal structure of the respective compounds, namely, whether or not the Ca ion is readily available to react with tetracycline.
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    Alkaline and acid phosphatase activities during growth of long bones and mandibles (1972)
    Springer
    Calcified tissue international 9 (1972), S. 173-178 
    Details
    ISSN: 1432-0827
    Keywords: Phosphatase ; Development ; Bone ; Growth ; Rhythm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Une étude longitudinale, par séries, est effectuée pour déterminer les activités en phosphatases acide et alcaline dans les os longs et la mandibule. Le pH optimum des deux enzymes se situe respectivement à 10.2 et 5.4 pour les phosphatases alcaline et acide. Des portées synchronisées de rats sont sacrifiées, à raison d'une portée par jour, en commençant au premier jour jusqu'au 25ème jour post-partum. Les spécimens sont analysés en ce qui concerne leur concentration en protéine et leur activité en phosphatases. Une activité de types élevée et faible est observée au niveau du tissu osseux, ainsi qu'un type d'activité faible en phosphatase alcaline, au cours des pics d'activité en phosphatase acide, et vice-versa. Les pics observés suggèrent une concordance entre l'activité en phosphatase et les autres changements biochimiques de la croissance osseuse, au niveau de la matrice organique et la formation minérale. Une étude séparée, tenant compte de la possibilité d'une activité enzymatique rythmique, suggère l'existence d'un rythme diurne court chez les animaux jeunes.
    Abstract: Zusammenfassung Eine serienmäßige Longitudinaluntersuchung wurde unternommen, um die Aktivitäten der alkalischen und sauren Phosphatase in den Röhrenknochen und den Mandibulae von Ratten zu bestimmen. Das pH-Optimum der beiden Enzyme wurde für die alkalische Phosphatase bei 10,2 und für die saure Phosphatase bei 5,4 ermittelt. Synchronisierte und randomisierte Würfe wurden getötet, 1 Wurf pro Tag vom 1.–25. Tag post partum. Die Proben wurden auf ihren Proteingehalt und ihre Phosphatasenaktivität untersucht. Ein Muster niedriger und hoher Aktivität konnte in beiden Knochengeweben beobachtet werden, sowie ein Muster von niedriger Aktivität der alkalischen Phosphatase bei Spitzenwerten der sauren Phosphatase und umgekehrt. Die beobachteten Spitzenwerte lassen einen Zusammenhang vermuten zwischen der Phosphatasenaktivität und den anderen biochemischen Veränderungen, die im wachsenden Knochen auftreten, d. h. Bildung der organischen Matrix und des Minerals. Eine getrennte Untersuchung, welche sich mit der Möglichkeit rhythmischer Merkmale der Enzymaktivität befaßte, läßt vermuten, daß in den ersten Tagen ein schwacher Tagersrhythmus bestehen könnte.
    Notes: Abstract A serial longitudinal study was undertaken to determine the activities of the alkaline and acid phosphatases in the long bones and mandibles. The optimum pH of the two enzymes was recorded at 10.2 and 5.4 for alkaline and acid phosphatase, respectively. Synchronized and randomized litters of rats were killed, 1 litter daily, starting at day 1 to day 25 post partum. Samples were analyzed for protein concentration and activity of the phosphatases. A pattern of low and high activity was observed in both bony tissues, as well as a pattern of low alkaline phosphatase activity during acid phosphatase activity peaks, and vice versa. The observed peaks suggest a correspondence between phosphatase activity and the other biochemical changes occurring in the growing bone, i.e., organic matrix and mineral formation. A separate study, considering the possibility of rhythmic features of the enzyme activity suggests that there may be a small diurnal rhythm at an early age.
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    Ultrastructure of sympathetic ganglion cells and granule-containing cells in the paracervical (Frankenhäuser) ganglion of the newborn rat (1972)
    Springer
    Cell & tissue research 126 (1972), S. 25-40 
    Details
    ISSN: 1432-0878
    Keywords: SIF-cells ; Short adrenergic neurons ; Biogenic amines ; Osmiophilic granules ; Innervation of uterus ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A study was made of the ultrastructure of the paracervical (Frankenhäuser) ganglion of the newborn rat, using immersion fixation by glutaraldehyde (2.5%) followed by OsO4 (1%), or KMnO4 (3%) fixation. The cells containing dense—core vesicles were divided into three groups: (1) primitive sympathetic cells, (2) cells containing some dense-core vesicles 700–1100 Å in size and structurally resembling sympathetic neurons, called principal neurons, and (3) cells containing many dense-core vesicles with a larger, darker dense core, 800–2000 Å in diameter, called granule-containing cells. Using glutaraldehyde-osmium fixation, the principal neurons were further divided into dark and light cells on the basis of electron opacity of the cytoplasmic matrix. The granule-containing cells were believed to correspond to the small, intensely fluorescent cells (SIF-cells) previously described using the formaldehyde-induced fluorescence technique. On the basis of the amount of granules, the granulecontaining cells were classified as mature or maturing SIF-cells and as more primitive SIF-cells, and developing sympathicoblasts. The development of synapses in autonomic ganglia was discussed.
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    Ultrastructure of the developing thymus of the leopard frog (Rana pipiens) (1972)
    Springer
    Cell & tissue research 127 (1972), S. 323-346 
    Details
    ISSN: 1432-0878
    Keywords: Thymus ; Frog ; Development ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A study of the ultrastructure of the developing thymus of the leopard frog (Rana pipiens) revealed that the thymus had undergone all of the major changes which would persist through larval life and metamorphosis by the time that the animals had reached larval stage IV of Taylor and Kollros (1946). These changes included development of an outer, lymphoid cortical region and an inner, essentially nonlymphoid medulla; mitotic activity among lymphoid cell precursors and the formation of the first small lymphocytes; development of complex cysts containing PAS-positive material and the appearance of other signs of secretory activity among epithelial cells of the medulla; and differentiation of large myoid cells containing bundles of striated muscle fibrils. The changes are particularly noteworthy because they first appear during a period in which the animals are known to be developing the capacity to respond immunologically to allografts.
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    URL: http://dx.doi.org/10.1007/BF00306877
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    The development of glio-vascular relationships in the rat spinal cord (1972)
    Springer
    Cell & tissue research 128 (1972), S. 555-563 
    Details
    ISSN: 1432-0878
    Keywords: Astrocytes ; Capillaries ; Spinal cord ; Blood brain barrrier ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Glio-vascular relationships were studied in the developing rat cervical spinal cord with electron microscopy. Capillaries were first evident on the eleventh prenatal day and were surrounded by undifferentiated cells and neuroblasts separated from the capillary wall by a perivascular space. This space persisted until day thirteen, when basement membranes began to appear. Small cellular processes containing glycogen were visible adjacent to the capillary basement membrane beginning at day fifteen and became more prominent as development proceeded. The origin of these cellular processes was not apparent, but they were most likely collaterals of epithelial elements. In prenatal animals neuroblasts or neurons were in direct contact with the capillary basement membrane. Cells resembling adult astrocytes were first observed during the nineteenth day. Astrocytic processes completely invested the capillaries, separating them from neurons in the spinal cord of all postnatal animals.
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    URL: http://dx.doi.org/10.1007/BF00306988
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    Ultrastructural changes in developing midgut epithelium of Calliphora erythrocephala meigen (1972)
    Springer
    Cell & tissue research 129 (1972), S. 278-289 
    Details
    ISSN: 1432-0878
    Keywords: Midgut epithelium ; Insects ; Development ; Metamorphosis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructural alterations in the anterior midgut epithelium of the fly Calliphora were investigated by electron microscopy. Nine developmental stages, from late larval to late adult, were studied. During metamorphosis, a tube is formed by proliferation of undifferentiated cells residing in cell nests in the basal part of the larval epithelium. The process of microvillus formation is described and compared with that in the embryonic stage. Differences between larval and imaginal cells were found in the rate of microvillus formation and in the occurrence of dense vesicles. The formation of a basal labyrinth coincides roughly with microvillus formation. Glycogen deposits occur mainly in the pupal stage and are almost always absent after emergence. Epithelial crypts are formed in late pupae by modification of the existing layer of cells together with a localized development of muscle fibres. In the adult stage changes may take place in the form of the cell apex, which generally assumes a more pointed shape, and in the amount of osmiophilic material, aggregating almost exclusively in the supranuclear part of the cell.
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    URL: http://dx.doi.org/10.1007/BF00306941
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