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  • Immunocytochemistry  (223)
  • Development  (182)
  • Springer  (402)
  • Frontiers Media
  • National Academy of Sciences
  • 2020-2022
  • 1980-1984  (221)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 34 (1983), S. 174-178 
    ISSN: 1570-7458
    Keywords: Lepidoptera ; Pyralidae ; Maruca testulalis ; Pod borer ; Development ; Nutritional suitability ; Host plant ; Crotalaria ; Vigna unguiculata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les possibilités de développement larvaire de Maruca testulalis sur les fleurs de huit espèces végétales ont été examinées en laboratoire. La comparaison a porté sur Crotalaria retusa, C. juncea, C. saltiana, C. misereniensis, C. mucronata, C. amazonas, Cajanus cajan et l'hôte principal de cette chenille, Vigna unguiculata. En tenant compte de la mortalité larvaire et des indices de croissance (G.I.), ces plantes ont été divisées en trois catégories principales: 1 celles provoquant une mortalité larvaire de 0–30% et ayant des G.I. ≥60%, constituent les plantes hôtes convenables (Vigna unguiculata seule); 2 les plantes qui provoquent une mortalité larvaire de 30≤50% et ont des G.I. de 30 à 60% de la plante hôte principale (Cajanus cajan, Crotalaria amazonas, C. saltiana, C. mucronata; 3 les plantes qui causent 50–100% de mortalité larvaire et dont les G.I. sont inférieurs à 30% de la plante hôte principale (Crotalaria retusa, C. juncea, C. misereniensis). Les résultats déjà publiés sur les choix du lieu de ponte des femelles et l'utilisation de C. juncea comme plante piège, sont discutés à la lumière de ces données nouvelles.
    Notes: Abstract Flowers of eight plant species were evaluated under laboratory conditions for their suitability as larval growth media for the cowpea pod borer, Maruca testulalis. The plants tested were Crotalaria retusa, C. juncea, C. saltiana, C. misereniensis, C. amazonas, Cajanus cajan and the principal host of the borer, Vigna unguiculata (cowpea), was included for comparison. Based on the data obtained on larval mortality and growth indices (GI) the plants were divided into 3 categories namely: I: Those causing 0–30% mortality and having GI value ≥60% form suitable host plants. This group only included V. unguiculata. — II: Those plant species causing 30≤50% larval mortality and having GI value 30%≤60% of the principal host plant (Cajanus cajan, Crotalaria amazonas, C. saltiana, C. mucronata). This group of species is marginally suitable as hosts. — III: Plants causing 50–100% larval mortality and having GI value ≤30% of principal host plant (C. retusa, C. juncea and C. misereniensis). Previously published data on the oviposition preference of the adult moth are discussed in the light of the present findings and the use of C. juncea as a possible trap crop.
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  • 2
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    Entomologia experimentalis et applicata 34 (1983), S. 251-256 
    ISSN: 1570-7458
    Keywords: Cyromazine ; Musca domestica ; Housefly ; Development ; Sensitivity ; Penetration ; Insect growth regulator
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé La cyromazine (N-cyclopropyl-1,3,5-triazine-2,4,6-triamine or CGA-72662) est un puissant inhibiteur de développement chez Musca domestica Le traitement des adultes par voie orale n'altère pas l'éclosion des œufs, mais inhibe fortement le développement des larves. Incorporée au milieu larvaire, elle donne une DL50 de 0.11 ppm. La sensibilité des pupes, traitées par application topique, décroit rapidement avec l'âge et est dépendante du solvant utilisé. Une heure après pupaison et avec le tétrahydrofuran comme vecteur, la DL50 est de 3 μg/g, soit 0.2 μg/g pour la pupe sans puparium. Comparé au méthanol. le tétrahydrofuran facilite la pénétration de la cyromazine pendant ce stade critique. La pénétration est également un facteur de la résistance des pupes agées. La toxicité de la cyromazine apparait rait donc principalement dépendante de sa vitesse de pénétration et de son accumulation dans l'organisme plutôt que de son métabolisme. Juste après pupaison, la jeune pupe chez M. domestica s'avère être un matériel sensible et pratique pour l'étude du mode d'action de la cyromazine.
    Notes: Abstract Cyromazine is a potent inhibitor of housefly (Musca domestica L.) larval development when administered orally to adults or incorporated into larval media, and of pupal metamorphosis on topical application shortly before or after pupariation. Pupae are most sensitive to cyromazine within 1 hr after pupariation and with tetrahydrofuran as the carrier solvent, giving topical LD50 values of 3 μg/g for the total puparium plus pupa and 0.2 μg/g calculated for the pupa only. Tetrahydrofuran is more effective than methanol in facilitating rapid cyromazine penetration during this critical pupal stage. The rate of cyromazine penetration or accumulation at sensitive stages appears to be more critical than the extent of metabolism in limiting cyromazine toxicity. Houseflies shortly after pupariation provide a sensitive and convenient organism for studies on cyromazine mode of action.
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  • 3
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    Calcified tissue international 12 (1973), S. 259-279 
    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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  • 4
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    Calcified tissue international 12 (1973), S. 313-321 
    ISSN: 1432-0827
    Keywords: Cathepsin D ; Extracellular ; Ossification ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé De la cathepsine D extracellulaire d'origine principalement ostéoblastique a été démontrée par immunohistochimie dans le cartilage en voide de calcification de cultures d'os des membres d'embryons de poulet. L'intérêt de ce fait pour l'ossification est discuté.
    Abstract: Zusammenfassung Es wurde mit einer immunohistochemischen Methode gezeigt, daß extrazelluläres Kathepsin D, welches hauptsächlich aus Osteoblasten gewonnen wurde, Knorpel von kultivierten Knochen von Kükenembryonen mineralisiert. Die Bedeutung dieser Feststellung für den Mechanismus der Knochenbildung wird diskutiert.
    Notes: Abstract Extracellular cathepsin D derived mainly from osteoblasts has been demonstrated immunohistochemically in ossifying cartilage of cultured embryonic chick limb bones. The relevance of this observation to the mechanism of ossification is discussed.
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  • 5
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    Calcified tissue international 16 (1974), S. 209-217 
    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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  • 6
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    Journal of molecular evolution 3 (1974), S. 109-113 
    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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  • 7
    ISSN: 1432-1432
    Keywords: 5S RNA ; Drosophila ; Evolution ; Secondary structure ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The nucleotide sequence ofDrosophila melanogaster 5S RNA has been determined and appears to be homogeneous both in the KC cell line and in the insect at different developmental stages. Experimental evidence on the conformation of this molecule is in agreement with a general class of 5S RNA models.
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  • 8
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    Development genes and evolution 182 (1977), S. 107-116 
    ISSN: 1432-041X
    Keywords: Drosophila ; Salivary glands ; Ecdysone ; Transcriptional control ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Injection of α-ecdysone into the larval haemolymph of late third instar larvae ofD. virilis induces both the extrusion of secretory proteins and the inactivation of the enzyme glutamine-fructose-6-phosphate-aminotransferase (E.C. 2.6.16) in the salivary glands. In the presence of actinomycin D or cycloheximide the hormone is ineffective. If before adding these inhibitors RNA synthesis is allowed to proceed for 1.5h, or protein synthesis for 2h after ecdysone injection, however, the protein extrusion and the enzyme inactivation do occur. It is proposed that ecdysone controls these two cytoplasmic events at the transcriptional level by the activation of specific Correlations with puff activities are discussed.
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  • 9
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    Development genes and evolution 183 (1977), S. 325-335 
    ISSN: 1432-041X
    Keywords: Gangliosides ; Sialoglycoproteins ; Acetylcholinesterase ; Brain ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The developmental accretion of up to nine individual gangliosides in foetal brains, peri- and postnatal cortices, postnatal cerebelli and olfactory lobes and in the liver and the spleen were investigated in mice and compared with that of glycoprotein-bound sialic acid and the activity of the acetylcholinesterase. In foetal brain and in postnatal liver and spleen more sialic acid was found bound to glycoproteins than to gangliosides. In postnatal brain structures, however, ganglioside-NeuAc predominated and increased between the 7th and 21st d about 2-fold in the olfactory lobes and cerebellum and more than 3-fold in the cortex. During foetal development the relative quantities (mol %) as well as the absolute concentrations (compared with the fresh weight) of GM1, GM2 and GM3 in the brain decreased, whereas those of GD1a, GD1b and GQ increased. This pattern change continued perinatally in the cortex up to the end of the first week. Thereafter the pattern changed little, but the concentration of all gangliosides present increased much more rapidly, especially between the 10th and 13th d. The postnatal cerebellum and olfactory lobes contained higher concentrations of GM1 and GM3 than the cortex, both gangliosides decreasing in favour of their di-, tri- and tetrasialo-homologues during the third postnatal week. In all brains structures the accretion of GD1a and GT1 was proportional to the increase in the activity of the acetylcholinesterase. Unlike the brain structures, the ganglioside pattern in the liver and spleen, characterised by a predominance of monosialogangliosides and of GD3, did not change noticeably during the first three weeks after birth. The coincidence of the changes in ganglioside accretion observed in the different brain structures with successive periods of morphological differentiation further support the suggestion that gangliosides may play an important role in control of the growth and differentiation of developing nerve cells.
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  • 10
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    Development genes and evolution 188 (1980), S. 55-63 
    ISSN: 1432-041X
    Keywords: Drosophila ; Compound eye ; shibire ts ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have analysed the effect of temperature on both developing and adult eye cell clones homozygous forshi ST139, a temperature-sensitive mutant ofDrosophila melanogaster. The mutant gene, autonomous in its cellular expression, causes structural modifications of ommatidial cells when adult clones of cells are exposed to the restrictive temperature (29°C) for several days. However, the mutant phenotype reverses to normal within 4 days at the permissive temperature (20°C). The results of pulse, shift-up and shift-down experiments show that the temperaturesensitive period for developing compound eye cells is from the late second instar up to the early pupa. Cytodifferentiation of compound eye cells is blocked by restrictive temperature treatment during this period, whereas cell proliferation does not seem to be directly affected. These results are discussed with regard to the other known aspects of the phenotype observed in mutant individuals.
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  • 11
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    Development genes and evolution 184 (1978), S. 273-283 
    ISSN: 1432-041X
    Keywords: Nervous system ; Development ; Imaginal discs ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The pathway of adult sensory nerves has been analysed in three experimental situations: (i) in flies with grossly abnormal thoracic morphology resulting from X-irradiation early during development, (ii) in flies which had been subjected to surgical operations late in the larval period, (iii) in homoeotic mutants. The results provide experimental support for a simple mechanism in which developing adult axons join the nearest larval nerve and are guided by it up to the central nervous system. In particular, experimental interference with normal development can result in nerves from different segments, or from dorsal and ventral appendages, joining each other and entering the central nervous system together.
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  • 12
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    Development genes and evolution 184 (1978), S. 325-350 
    ISSN: 1432-041X
    Keywords: Optic lobes ; Compound eyes ; Development ; Odonata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Des résultats antérieurs ayant montré une certaine dépendance du lobe optique envers l'oeil composé au cours du développement post-embryonnaire, il importait de préciser le rôle joué par les fibres post-rétiniennes qui relient ces deux organes. On pouvait, en particulier, se demander si l'activité mitotique du massif d'accroissement commun aux deux ganglions optiques externes (la lamina et la medulla) est contrôlée par le nombre de fibres postrétiniennes néoformées, ou bien si le rôle régulateur des fibres post-rétiniennes s'exerce plus tard, au moment de la différenciation des cellules ganglionnaires. Afin de répondre à ces questions trois types d'opération impliquant l'activité des fibres post-rétiniennes ont été pratiquées: (1) Une déficience en fibres post-rétiniennes néoformées a été obtenue par ablation de la zone d'accroissement oculaire et son remplacement par du tégument banal. (2) Une surcharge en jeunes fibres post-rétiniennes a été réalisée par l'induction de zones d'accroissement oculaires supplémentaires à la suite de rotations antéro-postérieures de volets oculaires. (3) Des “témoins-opérés” ont subi l'ablation, puis la remise en place immédiate de volets oculaires identiques à ceux des séries précédentes. Les résultats obtenus ont permis de préciser les processus régulateurs qui contrôlent la croissance du lobe optique en la rendant dépendante de la croissance de l'oeil sus-jacent. Cette régulation, qui consiste en un ajustement exact du nombre des cellules ganglionnaires fonctionnelles à celui des fibres postrétiniennes, s'exercerait à trois niveaux: (1) Une première régulation de la croissance contrôlerait le nombre total de neuroblastes dans le massif d'accroissement externe, la quantité de ces cellules embryonnaires étant d'autant plus élevé que la densité de fibres post-rétiniennes serait plus forte. Par contre, le taux mitotique du massif d'accroissement, qui s'est révélé invariable, ne serait pas sous le contrôle des fibres post-rétiniennes. (2) Une seconde régulation, beaucoup plus précise, s'effectuant dans la lamina, consisterait en la différenciation des seules cellules ganglionnaires contactées par les fibres post-rétiniennes néoformées, les cellules surnuméraires dégénérant alors rapidement. L'action différenciatrice s'exercant au niveau des autres ganglions, medulla et lobula, nécessiterait la présence à la fois des fibres post-rétiniennes à orientation centripètes, et des fibres centrifuges. (3) Un ultime processus régulateur, qui implique l'intégrité des fibres postrétiniennes, assurerait le maintien des cellules ganglionnaires fonctionnelles.
    Notes: Summary Since to earlier results indicated a dependence of the optic lobe on the compound eye during post-embryonic development, it appeared essential to specify the part played by the post-retinal fibres connecting these two organs. Especially, we wondered if the mitotic activity in the outer optic anlage common to the two outer optic ganglia (lamina and medulla) was controlled by the number of newly-neoformed post-retinal fibres, or if the regulating influence from the post-retinal fibres takes place later, during the differentiation of the ganglion cells. In order to answer these questions, three kinds of operation were performed: (1) removal, in young larvae, of the zone producing new ommatidia. This operation deprives the optic of the arrival of new post-retinal fibres below the operated level. (2) overloading of post-retinal fibres, by inducing zones that produced supernumerary ommatidia. (3) removal of an ocular volet, followed by its immediate reinsertion, to provide a “surgery-control”. The following results were obtained: (1) A preliminary growth regulation controlled the total number of neuroblasts in the outer optic anlage. However, the permanent mitotic activity of these cells was not controlled by post-retinal fibres. (2) A second regulation, much more precise, occurring in the lamina, consisted in the differentiation of the ganglion cells being affected by the new post-retinal fibres. The supernumerary cells then rapidly degenerated. (3) A last regulatory process, implying the integrity of post-retinal fibres, maintained the ganglion cells.
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  • 13
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    Development genes and evolution 191 (1982), S. 281-284 
    ISSN: 1432-041X
    Keywords: Mammals ; Brain cortex ; Gangliosides ; Glycoproteins ; AChE ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Developmental profiles of 11 gangliosides, concentration of lipid- and glycoprotein-bound sialic acid, and activity of AChE of the rat and mouse cerebral cortex were followed from the 7th day of gestation to the 21st postnatal day. There are three main changes in ganglioside concentration, which are similar in both species. The first occurs from gestation day 10 until birth: parallel to decreased proliferation, cell migration, and neuroblast differentiation, GM3 and GD3 in mouse cortex and GD3 in the rat's decreases in favor of GQ1b, GT1b, and GD1a. The second occurs from birth until the first postnatal week: Parallel to increased growth and arborization of dendrites and axons as well as synaptogenesis in rats and mice, there is a two-fold rise of GD1a, whereas GQ1b and GT1b remain on a nearly constant level. Concomitantly, GM3 and GD3 decreases. The third period of ganglioside changes starts in the second postnatal week, parallel to onset of myelination, and is characterized by an increase of GM1 in parallel with a decrease of the polysialogangliosides GT1b and GQ1b.
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  • 14
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    Development genes and evolution 191 (1982), S. 341-347 
    ISSN: 1432-041X
    Keywords: Physarum ; Development ; RNA ; Sequence complexity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Poly(A) RNA from S phase, G2 phase and starved macroplasmodia of Physarum contain mRNA sequences which when translated in vitro, yield similar patterns of polypeptides after fluorography. Reassociation of nick-translated DNA (Cot) allows the isolation of highly labeled single copy DNA which, after saturation hybridization with poly(A) RNA, gives values of 23% for growth and 17% for starvation. Homologous cDNA/poly(A) RNA hybridization reactions (Rot) indicate that 22–28% of the genome is transcribed during growth and 12% during starvation and that about half of the cDNA reacts with 0.1% of the genome and could represent 50–80 RNA species, each present in about 1,000 copies per nucleus. Up to 25,000 different RNA species, 1–5 copies each per nucleus, are estimated to be present during growth, and about 15,000 during starvation. Heterologous cDNA/poly(A) RNA hybridization reactions (Rot) indicate that the RNA sequences in S and G2 phase of the cell cycle are similar, with RNA sequences being more abundant in G2 phase. During starvation about 25% of the sequences present during growth cannot be detected and those sequences present during growth have become diluted during starvation.
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  • 15
    ISSN: 1432-041X
    Keywords: Vitellin ; Yolk granule ; Yolk protein ; Silkworm ; Embryogenesis ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Vitellin was purified from eggs of the silkworm,Bombyx mori, by a new method in which vitellin was extracted from isolated yolk granules. The purified vitellin had a molecular weight of 540,000. An antibody against purified vitellin was prepared in rabbits. It reacted with the hemolymph vitellogenin as well as with purified vitellin, but not with other proteins in the hemolymph or in the extract from yolk granules. The anti-vitellin IgG was used to immunocytochemically locate vitellin in theBombyx non-diapause egg during early developmental stages. In the egg, just after oviposition, vitellin was located in internal yolk granules and in small yolk granules of the periplasm. During the early developmental stages studied, vitellin was not metabolized uniformly throughout the egg. The vitellin of the internal yolk granules located at the posterior-dorsal part and of the small peripheral yolk granules was utilized in 16 h and 2 days, respectively, after oviposition. A thin, very vitellin-poor layer was located between the periplasm and the vitellin-rich interior in the newly laid egg. it was always in close contact with the periphery where blastoderm and germ-band cells developed.
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  • 16
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    Development genes and evolution 187 (1979), S. 35-47 
    ISSN: 1432-041X
    Keywords: Ascidia ; Concanavalin A ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The early development ofPhallusia mammillata eggs, dechorionated with trypsin and treated with Concanavalin A, was studied. Vital staining with a very dilute solution of acridine orange (0.01 μg/ml) helped to visualize the mitochondrial ‘crescent’ by fluorescence. At high concentrations of Concanavalin A (20–200 μg/ml) fertilized eggs did not cleave, but went through early ooplasmic segregation movements (formation of the crescent) and multinuclear syncytia were formed. At lower concentrations of Concanavalin A (less than 10 μg/ml), cleavage occurred, but the blastomeres remained rounded, leading to a grapelike embryo. Eggs attached to Concanavalin A treated nylon surfaces either did not cleave or produced grapelike embryos. Attachment of the eggs did not affect ooplasmic segregation. Considering modern theories of membrane structure it was concluded that Concanavalin A prevented cleavage either by immobilizing surface structures connected with microfilaments or by indirectly modifying other membrane structures. These structures could not have been involved in ooplasmic segregation, but their mobility was necessary for further morphogenesis.
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  • 17
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    Development genes and evolution 179 (1976), S. 373-392 
    ISSN: 1432-041X
    Keywords: Compound Eye ; Development ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The development of the rhabdomeric pattern in the compound eye ofDrosophila has been studied using combined transplantation and electron microscope techniques. In a first series of experiments eye imaginal discs of increasing age were implanted into larvae ready to pupate, thus losing variable amounts of the normal time for development. A sequence of differentiative abilities was found in the metamorphosed test pieces. As far as the photoreceptor cells are concerned, the most prominent steps of this sequence are: ability to form groups with other similar elements, anatomical polarization of microvilli, establishment of the rhabdomeric pattern and formation of an equator line. The stability of determination of the equator line was tested in a second experimental series. Fragment of different topographical origin within the mature eye anlage were brought to metamorphosis by implantation into larvae ready to pupate. It was found that an equator line differentiates only in those pieces which according to the published anlage maps contain the prospective equator region prior to metamorphosis. The mitotic abilities of implanted eye imaginal discs were investigated by means of “in vitro”3H-thymidine pulse-labelling and light microscope autoradiography of the differentiated test pieces. During the third larval stage the eye anlage is traversed by two consecutive mitotic waves, each one of them producing different categories of receptor cells. The first, anterior wave predominantly produces cells oriented toward the poles of the eye within the ommatidia, while the second, posterior wave gives rise to elements exclusively in an equatorial position. The dynamics of this proliferation are discussed in relation to the findings in the implantation experiments. Silver-grain counts support the possibility that at least two successive cell divisions occur in the eye anlage between labeling with tritiated thymidine and beginning of morphological differentiation. The relevance of this finding for the understanding of the concept of acquisition of competence is discussed.
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    Development genes and evolution 191 (1982), S. 159-162 
    ISSN: 1432-041X
    Keywords: Vitellogenin ; Hemagglutinin properties ; Yolk formation ; Insects ; Development
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    Topics: Biology
    Notes: Summary The sugar binding properties of 2 important vitellogenic proteins in Colorado beetle hemolymph were demonstrated by hemagglutination and precipitation experiments. The agglutination of human red blood cells by the hemolymph of reproducing females was observed up to a hemolymph dilution of 1/256, irrespective of the blood-group. It increased significantly after trypsinization of the crythrocytes. Vitellogenin 1 was identified as the hemagglutinin. Hemagglutination and hemagglutination inhibition tests showed that this protein has a low affinity for hexosamines and a higher affinity for sulfated polysaccharides. Precipitation tests demonstrated that besides vitellogenin, another major yolk protein, chromoprotein 2, reacts with sulfated polysaccharides. The possibility that there is a specific reaction of the vitellogenic proteins with well defined saccharides on the oocyte surface is discussed. This lectintype reaction may explain the selectivity of yolk precursor endocytosis.
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  • 19
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    Development genes and evolution 186 (1979), S. 27-50 
    ISSN: 1432-041X
    Keywords: Compound eye ; Development ; Determination of R7 cells ; sevenless mutant analysis ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary sev LY3,the only existing allele at thesev locus (1–33,2±0,2), behaves as strongly hypomorph or even as amorph. Ommatidia in asev compound eye have only seven receptor cells, the position of the R7 pattern element being vacant. Various criteria showing that the missing cell is R7 have been verified. These include (i) anatomical characteristics ofsev ommatidia; (ii) behaviour of central R cells insev rdgB double mutants; (iii) medullary projection of central R cell axons; and (iv) mitotic pattern ofsev imaginal discs. The analysis of morphogeneticsev-sev + mosaics has shown thatsev is expressed autonomously by R7 cells, indicating that thesev phenotype is not due to asev genotype of ommatidial pattern elements other than R7. The study of third instarsev imaginal discs has not brought any direct evidence for death of clustered presumptive R7 cells; however, clonal analysis of the developingsev compound eye has given evidence of developmental parameters comparable to those ofsev +, therefore favouring the hypothesis that R7 cells die insev mutants. On the other hand,sev + seems to be required for the determination of the R7 cells, since thesev phenotype cannot be uncovered during the last mitoses of heterozygous mutant cells.
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  • 20
    ISSN: 1432-041X
    Keywords: Protein synthesis ; Development ; Antherea pernyi ; Follicles ; Specific ribonuclease
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    Topics: Biology
    Notes: Summary Crude, cell-free protein-synthesizing systems were prepared from follicles of two different stages of development in the ovariole of the silkmothAntherea pernyi. The efficiency of the translation of natural and synthetic mRNAs in these systems was compared with that in a cell-free wheat germ system. A postmitochondrial extract (S-30) from the follicles almost completely inhibited protein synthesis in a polyribosome-dependent, cell-free systems. A specific ribonuclease, obtained from the post mitochondrial extract by ammonium sulphate precipitation, heat denaturation and DEAE-cellulose chromatography, inhibited polyribosome-dependent protein synthesis. The effect of this specific ribonuclease on the structural integrity of radioactive RNAs and ribosomal subunits, which were isolated from Ehrlich ascites tumor cells, was also studied.
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    Development genes and evolution 182 (1977), S. 329-346 
    ISSN: 1432-041X
    Keywords: Porifera ; Spongillides ; Gemmula ; Development ; Cell differentiation
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    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die beschalten Dauerstadien (Gemmulae) des SüßwasserschwammesEphydatia fluviatilis enthalten uniforme, totipotente Statocyten (Thésocyten), aus denen sich im Keimungsverlauf Archaeocyten (ein- und zweikernige) und Histoblasten differenzieren. Letztere treten nach einem gewissen Inkubationszeitraum in der zapfenartigen Zone unter der Mikropyle auf, während sich die übrigen Zelltypen zu einem an der Schalenöffnung orientierten, dreidimensionalen Muster gefälleartig anordnen. Nach Ausbildung eines einschichtigen Pinacocyten-Epithels (primäres Pinacoderm) aus peripher gelegenen, einkernigen Zellen schlüpft das nunmehr im Kapselinneren entstandene Primordium durch die offene Mikropyle und nimmt mit dem Substrat Verbindung auf. Das Primordium entwickelt sich zum frühen Jungschwamm, in den die restlichen Archaeocyten, Histoblasten und auch vereinzelt Skleroblasten einwandern.
    Notes: Summary The dormant shelled gemmulae of the fresh water spongeEphydatia fluviatilis contain uniform, totipotent statocytes (thésocytes), which can differentiate either into archaeocytes (mono- and binucleated) or into histoblasts. The histoblasts accumulate at the villus near the micropyle. The other cell types orientate in a three-dimensional pattern at the micropyle, according to a developing gradient. After the primary pinacoderm is formed, the sponge primordium is released through the open micropyle. The primordium develops into a new sponge, into which archaeocytes, histoblasts and scleroblasts migrate.
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    Development genes and evolution 184 (1978), S. 1-13 
    ISSN: 1432-041X
    Keywords: Cell division ; Development ; Cryptobiosis ; Nauplius larva
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    Topics: Biology
    Notes: Summary Cell division during embryonic development of the brine shrimp,Artemia salina has been studied by counting nuclei and mitotic figures. No cell division was observed during development of the encysted gastrula until about an hour before emergence of the embryo (a pre-nauplius) from the cyst, and even then only a few mitotic figures were observed. Following emergence, and during further development up to the stage II nauplius larva an increase of about 25% in the number of cells occurs. However, when the newly hatched larva is exposed to FUdR (10 μg/ml) cell division is largely inhibited, but observable development nevertheless proceeds normally. Evidently all processes involved with the development of the gastrula into a stage II nauplius larva can occur with far fewer cells than normally are present.
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  • 23
    ISSN: 1432-041X
    Keywords: Major haemolymph proteins ; Development ; Cuticle ; Immunocytochemistry ; Ceratitis capitata
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    Notes: Summary The developmental profile of the major haemolymph proteins (ceratitins) inCeratitis capitata was studied. Ceratitin concentration in the haemolymph decreases dramatically during the last days of pupal life, while the amounts of ceratitins in whole organism extracts remain unchanged. By electrophoretic, immunological and immunofluorescence techniques it was revealed that ceratitins are reabsorbed by the fat body and a fraction of them is deposited in the cuticle. The possible role of ceratitins is discussed.
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  • 24
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    Development genes and evolution 181 (1977), S. 227-245 
    ISSN: 1432-041X
    Keywords: Compound eye ; Development ; Cell lineages ; Genetic mosaics ; Drosophila
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    Topics: Biology
    Notes: Summary The generalogical relationships of photoreceptor cells within the compound eye ofDrosophila have been studied using cell labelling, with either3H-thymidine or recessive mutations, during the third larval stage. It has been found that photoreceptor and secondary pigment cells arise from different precursor cells. Under the present experimental conditions, precursors of receptor cells give rise to about 8 elements which differentiate as R cells of two different groups. One of the cells differentiates as R7 and the remaining as any one of the R1 to R6. The last cells behave initially as equivalent, and can differentiate within the same or within different, but neighbouring, ommatidia. The class of R1 to R6 cell in which each one of these elements differentiates, seems to depend on the time of its origin. The implications of these findings for the formation of the ommatidial pattern are discussed.
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    Development genes and evolution 188 (1980), S. 205-213 
    ISSN: 1432-041X
    Keywords: Gangliosides ; Development ; Brain ; Chicken
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    Topics: Biology
    Notes: Summary The developmental profiles of 15 different gangliosides of the optic lobes and cerebrum of the chicken were followed from the 6 th day of incubation to hatching and correlated to morphological development. Five of these gangliosides appearing in both structures between the sixth and tenth day, have not been reported previously in higher vertebrates. Three chromatographed on TLC-plates similarly to GT3, GT2, and GT1c gangliosides, which have been demonstrated in fish brain. One fraction moved just below GQ1b and is suggested, to contain GQ1c. These “novel” gangliosides, which are possibly related to a recently proposed separate and probably phylogenetically older biosynthetic pathway, contained up to 20% of total ganglioside sialic acid. The fifth “novel” fraction, containing up to 16% of total ganglioside-sialic acid, moved below the penta-sialoganglioside GP1 and is suggested to contain hexa-sialogangliosides. There were two main changes in ganglioside synthesis, which were identical in both structures. The first occurred from the sixth to the eleventh day, parallel to decreased proliferation, maximal cell migration and neuroblast differentiation, GD3 and GD2 decreased rapidly in favour of GQ1b, GP1, and to the “novel” fractions, described above. The second occurred from the eleventh to the eighteenth day, parallel to increased growth and arborization of dendrites and axons as well as functional establishment of synaptic contacts, there was a sharp rise in the amount of GD1b, GT1b, and GD1a. Concomitantly the “novel” gangliosides decreased. At hatching GD1a was the predominant ganglioside. GM3, GM2, and GM1 were always minor fractions, each accounting for less than 4% of total ganglioside-sialic acid. GM4 was never detected, indicating neglegible myelinisation until hatching.
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    Development genes and evolution 189 (1980), S. 171-180 
    ISSN: 1432-041X
    Keywords: Amino acyl-tRNA synthetases ; Development ; Nuclear-mitochondrial interactions ; Neurospora
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    Topics: Biology
    Notes: Summary The specific activities of the branched chain amino acyl-tRNA synthetases from the cytosolic and mitochondrial fractions ofN. crassa were low in dormant conidia and increased during germination, reaching a maximum 8 h after inoculation. This stage of development is characterised by high rates of many other cellular activities. The increases in activity of synthetases of both cytosol and mitochondria are inhibited by cycloheximide indicating that they are synthesized on cytoplasmic ribosomes. The mitochondrial synthetases show a stimulation of their specific activity when mitochondrial RNA and protein synthesis are inhibited by either ethidium bromide or chloramphenicol suggesting that a mitochondrial translation product regulates the synthesis of the mitochondrial synthetases. The activities of amino acyl-tRNA synthetases are dependent on energy production. When respiration is uncoupled from oxidative phosphorylation, synthetase specific activities decrease although the activities of other mitochondrial enzymes like NADH-dehydrogenase increase. This phenomenon suggests that more than one mechanism regulates the synthesis of mitochondrial proteins which are formed on cytoplasmic ribosomes. The synthesis of branched chain amino acyl-tRNA synthetases ofNeurospora is neither repressed by their cognate amino acids, nor is there inhibition by the precursors of these amino acids, as has been observed in other amino acyl-tRNA synthetases of various organism includingNeurospora.
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  • 27
    ISSN: 1432-041X
    Keywords: Mollusca ; Cleavage ; Junctions ; Interaction ; Development
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    Notes: Summary In early cleavage stages ofLymnaea stagnalis, three kinds of intercellular junctions could be distinguished up to the sixth cleavage: intermediate, septate and gap junctions. The first two form “junctional belts” located on the cell border at the periphery of the embryo. For the purpose of our study we were most interested in gap junctions as they are alleged to be structures that allow cell-to-cell communication. Gap junctions first appear at the four cell stage. Up to the sixth cleavage no difference in the distribution pattern could be found between and within each of the four quadrants of the embryo. Some of the cell tiers along the animal-vegetal axis lack gap junctions either between the blastomeres within the tier or between the blastomeres from adjacent tiers. All gap junctions observed in freeze fracture replicas show plaques with an irregular IMP pattern. The average IMP diameter measures 12 nm (SD±2 nm). In stages fixed after the fifth cleavage, gap junctions are found between micromeres at the animal pole and the central 3D macromere. This is in agreement with the presumed interaction between these cells at this stage. The possibility of a transition of non-functional into functional gap junctions after the fifth cleavage is discussed.
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    Development genes and evolution 191 (1982), S. 143-148 
    ISSN: 1432-041X
    Keywords: Amphibia ; Junctions ; Interaction ; Development ; Freeze fracture
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    Topics: Biology
    Notes: Summary Using freeze-fracture electron microscopy and fluorescent dye injection we have analysed the contacts between cells of the deeper endoderm taken from neurulae ofXenopus laevis. Endodermal cells in situ have large 1.5 μm diameter gap junctions composed of 8 nm P-face particles and corresponding E-face pits. Beside gap junctions, particle aggregates typical of desmosomal plaques are present but there are no tight junctions. The dissociation of endoderm into single cells involves profound structural alterations in the surface membrane including the complete disappearance of junctional structures among them gap junctions. The reaggregation of endoderm cells leads to the restoration of the surface membrane IMP (Intra Membrane Particle) pattern and, after ca. 30 min, to the establishment of functional pathways allowing for the intercellular transfer of fluorescent dye. Concomitantly gap junctions reappear. The observation that the dissociation and reaggregation of endodermal cells involves IMP alterations which go beyond the cell junctions themselves is discussed as an adaptation of the plasma membrane to changing environmental conditions.
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  • 29
    ISSN: 1432-041X
    Keywords: Mollusca ; Interaction ; Development ; Dye-coupling ; Gap junctions
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    Notes: Summary During the early development of the molluscPatella, the dorsoventral axis is established after the fifth cleavage due to direct interaction between the animal micromeres and one of the vegetal macromeres. This vegetal macromere is thereby induced to become the mesentoblast mother cell (3D). In this study we have examined intercellular communication in earlyPatella embryos by monitoring the transfer of the fluorescent dye, Lucifer Yellow, upon iontophoretic injection into blastomeres between the second and sixth cleavage. Up to the fifth cleavage dye transfer is detectable neither inin toto embryos nor in serial sections. Shortly after the fifth cleavage dye-coupling between blastomeres becomes apparent. This occurs approximately 40 min before the interaction between animal micromeres and the future mesentoblast mother cell. Inspection of serially sectioned embryos after dye-iontophoresis in either animal micromeres or in the central macromere 3D showed the absence of direct dye-transfer between these cells at the stage of interaction. The reduced rate of dye-transfer from the 3D macromere to its dorsal neighbour 2d2 suggests a bilateral symmetrical transfer pattern, the axis of which corresponds with the dorsoventral axis at the sixth cleavage. Cell deletion experiments demonstrated that the establishment of dye-coupling between the vegetal macromeres occurs independently of the interaction between animal and vegetal blastomeres.
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    Development genes and evolution 190 (1981), S. 33-39 
    ISSN: 1432-041X
    Keywords: Ceratitis capitata ; Major haemolymph proteins ; Development ; Fat body ; Secretion
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    Topics: Biology
    Notes: Summary The accumulation of major haemolymph proteins (a group of proteins immunologically related to Calliphorin) their biosynthesis in vivo and in organ culture as well as their secretion, has been studied during the late larval stages and white pupae of the Mediterranean fruit flyCeratitis capitata. The accumulation of major haemolymph proteins in the haemolymph, shows a twenty fold increase from the 4-day old larvae to the white pupae stage, while in the fat body there is only a seven fold increase. It is evident from the in vivo and organ culture studies, that the major haemolymph proteins are synthesized during the late larval stage and their synthesis declines abruptly during the stage of white pupae. It seems also that each polypeptide has its own characteristic developmental kinetics of synthesis. The major haemolymph proteins are synthesized in the fat body and are very quickly secreted into the haemolymph.
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    Calcified tissue international 7 (1971), S. 267-276 
    ISSN: 1432-0827
    Keywords: Tech ; Development ; Enamel ; Enzyme ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé L'activité en naphtylamidase est étudiéc au niveau des incisives et molaires de rat, à divers stades de développement. Du L-leucyl-4-methoxy-2-naphtylamide, du L-alanyl-4-methoxy-2-naphtylamide, du L-leucyl-2-naphthylamide et du DL-alanyl-2-naphtylamide sont utilisés comme substrats: du bleu rapide B et du grenat rapide GBC sont employés comme sels de diazonium. Le naphtylamidase n'est pas visible au niveau de dents, en voie de dévelopment, au cours de la formation matricielle de l'émail. A la fin de ce stade, le naphtylamidase est présent au niveau de l'extrémité distale des améloblastes, près de la surface de l'émail. L'activité enzymatique reste identique jusqu'au moment de la fusion de l'épithélium dentaire et de l'épithélium buccal, au moment de l'éruption de la dent dans la cavité buccale. On ne rencontre pas de naphtylamidase au niveau d'autres tissues dentaires; cependant une activité marquée est observée dans les ostéoclastes au niveau des surfaces de résorption de l'os alvéolaire, entourant les dents, en voie de développement et d'éruption, et dans certaines régions du tissu conjonctif.
    Abstract: Zusammenfassung Die Aktivität der Naphthylamidase wurde in den Backen- und Schneidezähnen von Ratten in verschiedenen Entwicklungsstufen studiert. Als Substrate wurden L-leucyl-4-methoxy-2-naphthylamid, L-alanyl-4-methoxy-2-naphthylamid, L-leucyl-2-naphthylamid und DL-alanyl-2-naphthylamid verwendet; als Diazoniumsalze dienten Echtblau B und Echt-Granat GBC. Naphthylamidase konnte während der Schmelzmatrixbildung im Zahn nicht nachgewiesen werden. Nach Abschluß dieser Phase erschien Naphthylamidase in den distalen Enden der Ameloblasten, nahe bei der Schmelzoberfläche. Die Enzymtätigkeit blieb am selben Ort lokalisiert, bis das Zahnepithel, im Augenblick wo der Zahn in die Mundhöhle durchstößt, in das Mundepithel überging. Naphthylamidase wurde in anderen Zahngeweben nicht gefunden, aber eine deutliche Aktivität konnte in gewissen Bezirken des Bindegewebes sowie in den Osteoklasten der resorbierenden Oberflächen vom alveolären Knochen festgestellt werden, welcher die sich bildenden und die hervorstoßenden Zähne umgibt.
    Notes: Abstract Naphthylamidase activity was studied in rat molar and incisor teeth at different stages of development. L-leucyl-4-methoxy-2-naphthylamide, L-alanyl-4-methoxy-2-naphthylamide, L-leucyl-2-naphthylamide and DL-alanyl-2-naphthylamide were used as substrates and Fast blue B and Fast Garnet GBC as diazonium salts. Naphthylamidase was not demonstrable in the teeth during enamel matrix formation. After the termination of this stage, naphthylamidase was present in the ameloblasts in their distal ends close to the enamel surface. The enzyme activity retained this localization until the dental epithelium fused with the oral epithelium at the time of tooth eruption into the oral cavity. Naphthylamidase was not found in other dental tissues, but marked activity was found in osteoclasts at the resorbing surfaces of alveolar bone surrounding the developing and erupting teeth and in certain areas of the connective tissue.
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    Calcified tissue international 9 (1972), S. 122-130 
    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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    Calcified tissue international 24 (1977), S. 223-229 
    ISSN: 1432-0827
    Keywords: Enamel-cementum-morphology ; Immunocytochemistry ; Biochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The continuously erupting rabbit incisor tooth is normally thought of as having an enamel covered “crown” on its labial surface and a cementum covered “root” on its lingual surface. We have examined both surfaces of continuously erupting rabbit incisor teeth taken from near term embryos by a variety of means, including transmission and scanning electron microscopy, biochemical fractionation, and immunohistochemistry. In all cases, we could detect no qualitative difference in the early extracellular matrices taken from the labial and lingual surfaces of the teeth. Both matrices were shown to be composed of dentin and enamel, although the thickness and geometry of the enamel matrix on the lingual surface was somewhat different from that on the labial surface.
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    Calcified tissue international 9 (1972), S. 173-178 
    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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  • 35
    ISSN: 1432-2048
    Keywords: Immunocytochemistry ; Lectin (localization) ; Phaseolus (lectin) ; Phytohemagglutinin ; Seed (lectin)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have examined the properties and subcellular localization of phytohemagglutinin (PHA), the major lectin of the common bean (Phaseolus vulgaris.), in the axis cells of nearly mature and imbibed mature seeds. On a protein basis the axis contained about 15% as much PHA as the cotyledons. Localization of PHA was done with an indirect immunolabeling method (rabbit antibodies against PHA, followed by colloidal gold particles coated with goat antibodies against rabbit immunoglobulins) on ultra-thin cryosections which were embedded in plastic on the grids after the immunolabeling procedure. The embedding greatly improved the visualization of the subcellular structures. The small (4 nm) collodial gold particles, localized with the electron microscope, were found exclusively over small vacuoles or protein bodies in all the cell types examined (cortical parenchyma cells, vascular-bundle cells, epidermal cells). The matrix of these vacuoles-protein bodies appears considerably less dense than that of the protein bodies in the cotyledons, but the results confirm that in all parts of the embryo PHA is localized in similar structures.
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  • 36
    ISSN: 1432-2048
    Keywords: Avena ; Immunocytochemistry ; Phytochrome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phytochrome of oat (Avena sativa L., cv. Garry) coleoptile cells in the red-light-absorbing form, Pr, is diffusely distributed while after conversion to the far-red-light-absorbing form, Pfr, it is observed only in very small areas within the cell. Comparison of phytochrome photoversibility measurements to the distribution of the pigment within the cell indicates that the spectral assay is not influenced by the observed compartmentalization of the chromoprotein. However, the observed compartmentalization of phytochrome is correlated with a loss in spectrophotometrically detectable Pr.
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  • 37
    ISSN: 1432-2048
    Keywords: Cotyledons ; Endoplasmic reticulum ; Ferritin labeling ; Immunocytochemistry ; Phaseolus ; Protein (reserve) ; Reserve protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The ultrastructure of the storage parenchyma cells of the cotyledons of developing bean (Phaseolus vulgaris L.) seeds was examined in ultrathin frozen sections of specimens fixed in a mixture of glutaraldehyde, formaldehyde and acrolein, infused with 1 M sucrose, and sectioned at-80° C. Ultrastructural preservation was excellent and the various subcellular organelles could readily be identified in sections which had been stained with uranyl acetate and embedded in Carbowax and methylcellulose. The cells contained large protein bodies, numerous long endoplasmic reticulum cisternae, mitochondria, dictyosomes, and electron-dense vesicles ranging in size from 0.2 to 1.0 μm. Indirect immunolabelling using rabbit immunoglobulin G against purified phaseolin (7S reserve protein), and ferritin-conjugated goat immunoglobulin G against rabbit immunoglobulin G was used to localize phaseolin. With a concentration of 0.1 mg/ml of anti-phaseolin immunoglobin G, heavy labeling with ferritin particles was observed ober the protein bodies, the cisternae of the endoplasmic reticulum, and the vesicles. The same structures were lightly labeled when the concentration of the primary antigen was 0.02 mg/ml. Ferritin particles were also found over the Golgi bodies. The absence of ferritin particles from other organelles such as mitochondria and from areas of cytoplasm devoid of organelles indicated the specificity of the staining, especially at the lower concentration of anti-phaseolin immunoglobulin G.
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  • 38
    ISSN: 1432-2048
    Keywords: Immunocytochemistry ; (PEP carboxylase) ; PEP carboxylase ; Sorghum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The localization of phosphoenol pyruvate carboxylase (EC 4.1.1.3.1.) in the leaf cells of Sorghum vulgare was investigated by using three techniques: the conventional aqueous and non aqueous methods gave conflicting results; the immunocytochemical techniques clearly showed that the enzyme is predominantly located in the cytoplasm of mesophyll cells.
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  • 39
    ISSN: 1432-2048
    Keywords: Cotyledons ; Brassica ; Development ; Intracellular localization ; Lipase ; Microsomal membrane fraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In homogenates of resting rapeseeds no lipase activity (glycerolester hydrolase, EC 3.1.1.3) could be detected using a titrimetric assay procedure. Following a 30-h lag-phase after imbibition, lipase activity increased sharply, reaching its maximum at day 4 after sowing. Simultaneously triglyceride content of the cotyledons decreased sharply. At any time during the 11-day period of seedling growth examined, only an alkaline lipase activity with a pH optimum around 9 was present. White light had essentially no effect on the development of lipase activity. However, the disappearance of lipase activity from the cotyledons after fat utilization was found to depend on nitrogen nutrition of the seedlings. The activities of the glyoxysomal enzymes catalase and malate synthetase showed the usual rise and fall patterns with peak activities at day 4 after sowing, independently of the mineral nutrition of the seedlings. About 90% of the lipase activity was associated with a microsomal membrane fraction. Resolution of this fraction by sucrose density gradient centrifugation (62,000 g for 14 h) yielded three distinct membrane fractions. Maximum activities of membrane marker enzymes were recovered from the gradients at following densities: The major portion of microsomal protein and lipase activity at 1.085 kg/l; microsomal malate synthetase and phosphorylcholineglyceride transferase at 1.116 kg/l; NADH-cytochrome c reductase and phosphorylcholinecytidyl transferase at 1.133 kg/l. Evidently in rapeseed cotyledons lipase activity is associated only with a discrete microsomal membrane fraction which sediments differently from membrane fractions of the endoplasmic reticulum.
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  • 40
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    Archives of microbiology 96 (1974), S. 353-364 
    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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  • 41
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    Archives of microbiology 99 (1974), S. 331-344 
    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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  • 42
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    Archives of microbiology 99 (1974), S. 155-166 
    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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  • 43
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    Environmental management 6 (1982), S. 1-7 
    ISSN: 1432-1009
    Keywords: Natural resource planning ; Development ; Policy analysis ; Industrial siting ; Environmental impact assessment
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    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The problem of management of industrial residuals can be reduced through a rational system for siting and planning major industrial facilities. In the United States, Wyoming has moved in the direction of establishing a one-stop permitting system that provides important information for air and water quality planning and solid waste management with a minimum of regulatory overlap. This paper describes Wyoming's Industrial Development Information and Siting Act of 1975 and suggests ways in which the Wyoming permitting system can be improved and applied elsewhere.
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  • 44
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    Environmental management 4 (1980), S. 13-20 
    ISSN: 1432-1009
    Keywords: Planning ; Management ; Natural resource planning ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Since October 1977, the East-West Environment and Policy Institute in Honolulu has been conducting a multinational collaborative project to enhance the preparation and utilization of natural systems assessments in developing countries. This paper presents some of the findings to date: 1. Channels are developing rapidly for transferring ecological knowledge into political and administrative decision making. 2. The systematic approach of ecology is replacing “environmental quality” as the organizing concept for information about natural resources and the environment. 3. Benefit-cost analysis is a promising method for integrating ecological knowledge into economic development decision making. 4. The lack of baseline information, inventories, and predictive capability will not be remedied soon or easily; thus priorities for ecological research are essential.
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  • 45
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    Archives of microbiology 129 (1981), S. 349-352 
    ISSN: 1432-072X
    Keywords: Rhizobium ; Bacteroids ; Viability ; Development
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    Topics: Biology
    Notes: Abstract Viability of Rhizobium leguminosarum bacteroids isolated from Pisum sativum was determined after sucrose gradient centrifugation of the bacteroids resulting in separation according to developmental stage. The results suggest that past a critical stage of development bacteroids lose viability. Similar experiments with R. japonicum bacteroids having a lower degree of morphological differentiation showed an appreciably higher viability in all gradient fractions. The results support the hypothesis that bacteroid morphology and viability is dependent on the nature of—and length of exposure to—the host plant cytoplasm.
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  • 46
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    Archives of microbiology 103 (1975), S. 231-236 
    ISSN: 1432-072X
    Keywords: Chamaesiphonosira cymbellicola ; Budding Bacteria ; Development ; Epiphytism ; Cyanophycaea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Chamaesiphonosira cymbellicola n. gen., n. sp., entwickelt lang-kegelige, farblose Zellen, die mit der breiteren Basis festsitzen und an der Spitze bis zu 30 eine später zerfallende Kette bildende Knospenzellen abschnüren. Es ergibt sich daraus eine äußerliche ähnlichkeit mit der Cyanophycee Chamaesiphon, doch besteht keine cytologische Übereinstimmung. Die Art kommt ausschließlich auf lebenden Zellen der Diatomee Cymbella cesati vor, trotz reichlichem Angebot vieler anderer ähnlicher Diatomeen und anderer Algen; es handelt sich also um einen sehr spezialisierten Epiphytismus. Außerdem werden bestimmte Stellen der “Wirts” pflanze bevorzugt. Eine Schädigung tritt nicht ein; es erfolgt Übertragung auf die Epitheken der Tochterzellen. Systematisch läßt sich die Gattung am besten in den Caulobacterales sensu Henrici u. Johnson (1935) unterbringen. Als zweite Art ist offenbar Chamaesiphon hyalinus Scherffel (1907) zu ihr zu stellen.
    Notes: Abstract The organism shows long-conical, colourless cells of bacterial size, affixed with the broader basis and cutting off buds from the free apex in numbers as high as 30, which form a chain and later separate. Multiplication is entirely by budding. Some resemblance to Cyanophycean cells, in particular to the exosporangia of Chamaesiphon, seems to be cytologically not verified. The organism grows exclusively on living cells of the diatom Cymbella cesati, and is fixed to them principally on the edges of the valvae. In spite of the presence of many other similar diatom species, the organism represents a remarkable case of extremely specialized epiphytism. There are no signs of damage of the “host” cell, in cell division the epiphyte is taken over by the epithecae of the daughter cells. Systematically the species because of practical reasons can be included into the Caulobacterales sensu Henrici and Johnson (1935). A second species, obviously belonging in here, is represented by Chamaesiphon hyalinus Scherffel (1907).
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  • 47
    ISSN: 1432-072X
    Keywords: Achlya ; Ribonuclease ; Development ; Sporangium ; Lysogome ; Inhibitors poly(A)+RNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The present paper describes intracellular changes in ribonuclease specific activity during Ca2+-induced sporangium formation in the water mold Achlya bisexualis. The enzymes undergo a decrease in activity prior to crosswall formation followed by an increase in activity during spore cleavage. As spore discharge occurs the RNase activity again decreases. A large percentage of the nuclease activity is associated with a lysosomal-like fraction of the cell, but there is also considerably activity associated with nuclear and microsomal fractions. Addition of cycloheximide or actinomycin D at various times during development prevents further decrease or increase in the enzyme activity. Mixing of cell extracts from different developmental stages provides evidence that inhibitors or activators of the enzyme activity are not responsible for the activity levels evident at the different stages. There is a change in the total levels of presumptive mRNA during Ca2+-induced sporangial formation which appears to be associated with the patterns of RNase activity. Utilizing total cellular RNA and Poly(A)+ RNA with the crude ribonuclease preparations, no substrate specificity could be ascertained.
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  • 48
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    Archives of microbiology 117 (1978), S. 221-226 
    ISSN: 1432-072X
    Keywords: Nematophagous fungus ; Giant functional traps ; Mutation ; Development
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    Topics: Biology
    Notes: Abstract Mutagenesis with nitrosoguanidine yielded two classes of ring trap mutants in the predacious HyphomyceteDactylella brochopaga: strains which could make no traps and those with a proportion of giant, functional traps. A third strain, derived from a trapless strain made abnormally small functional traps. The giant traps are described, together with developmental abnormalities they sometimes display. The characteristics of the chief mutant strains are discussed.
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  • 49
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    Archives of microbiology 101 (1974), S. 391-399 
    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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  • 50
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    Archives of microbiology 104 (1975), S. 285-288 
    ISSN: 1432-072X
    Keywords: Vibrio alginolyticus ; Flagella ; Development
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    Topics: Biology
    Notes: Abstract The development of peritrichous flagella and, consequently, swarming of Vibrio alginolyticus depend on a complex relationship between temperature, salt concentrations and pH. At temperatures above 28°C V. alginolyticus did not develop peritrichous flagella unless certain minimal concentrations of NaCl are present: the higher the temperature, the higher the NaCl concentrations required for peritrichous flagella synthesis. This requirement for NaCl at high temperatures is much more pronounced at pH 9 than at pH 6. High temperatures and low concentrations of NaCl also inhibited swarming of cells already armed with peritrichous flagella. Other cations, such as Li+, K+ and Mg2+, replaced NaCl only at temperatures below 28°C.
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  • 51
    ISSN: 1432-072X
    Keywords: Claviceps purpurea ; Ultrastructure ; Development ; Sclerotium ; Oleosomes
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    Topics: Biology
    Notes: Abstract The development of sclerotia of Claviceps purpurea was investigated by light and electron microscopy. During the first days after infection sterigma and conidiospores are formed. The spores show a moderately developed vacuolar system, they are thick walled and contain about 20% lipid (related to the cell volume) embedded in glycogen. The sterigma are cylindrical unicellular hyphae with electron dense cytoplasm and isolated strongly contrasted lipid droplets. In maturing sclerotia the hyphae become septated with increasingly thick cell walls and a large lipid content. The lipid forms small droplets in young cells, while in the mature sclerotium it occurs in the form of very large drops, occupying the major part of the cell. Simultaneously the composition of the lipid is changed. The mature cells have several nuclei. They are partially connected by osmiophilic substances, forming a network of intercellular spaces.
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  • 52
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    Archives of microbiology 113 (1977), S. 309-313 
    ISSN: 1432-072X
    Keywords: Cellulose enzyme system ; Development ; Acanthamoeba
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    Topics: Biology
    Description / Table of Contents: Zusammenfassung In Extrakten wachsender Kulturen von Acanthamoeba castellanii konnte ein cellulose-abbauendes Enzymsystem nachgewiesen werden. Es besteht aus einer reduzierende Zucker abspaltenden Komponente mit einem pH-Optimum bei 4, einer viscositätsverändernden Komponente mit einem pH-Optimum bei 6 und einer β-Glucosidase mit einem pH-Optimum von 3,5. Bei pH 4 sind die Celluloseabbauprodukte Cellobiose und Glucose, bei pH 6 höhermolekulare Oligosaccharide. Während der Entwicklung in einem nährstofffreien Salzmedium nehmen die Cellulaseaktivitäten ab: Vor dem Start der Cellulosesynthese sind noch etwa 30% der ursprünglich vorhandenen Celluloseaktivität nachzuweisen, fertige Cysten besitzen noch etwa 10% der Aktivität. Die Bedeutung des Cellulassenzymsystems wird ausgehend von der Tatsache diskutiert, daß die Excystierung ohne Abbau der Cystenwand, in die die Cellulose eingelagert ist, stattfindet.
    Notes: Abstract It could be shown that extracts of growing cultures of Acanthamoeba castellanii contained a cellulose degrading system. Reducing sugars are split off by one component of this system at an optimum of pH 4, another enzyme changes the viscosity at an optimum of pH 6, and a third component is a β-glucosidase with an optimum at pH 3.5. At pH 4 the cellulose degradation products are cellobiose and glucose; at pH 6 higher molecular weight oligosaccharides are produced. During the development from trophozoites to cysts in a nutrient-free medium, the activities of both cellulases decline: Prior to the start of cellulose synthesis only 30%, and in cysts only 10% of the original existing activities are detectable. The biological function of the cellulase enzyme system is discussed together with a consideration of the fact that excystment takes place without digestion of the cyst wall in which the cellulose is deposited.
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  • 53
    ISSN: 1432-072X
    Keywords: Physarum polycephalum ; Amoebae ; Aminopeptidases ; Acid proteases ; Regulation ; Development ; Differential gene activity
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    Topics: Biology
    Notes: Abstract The cultivation of Physarum polycephalum amoebae in two media with different protein contents revealed a regulation of aminopeptidases and proteases depending on the albumin content of the medium: in growing amoebae and plasmodia the aminopeptidases have similar isoenzyme patterns and relative activities against nitroanilides. One alanine and four leucine aminopeptidase isoenzymes were found within the slightly acid pH range. During growth amoebae secrete—different from plasmodia—leucine aminopeptidase into the medium with low protein content. In an albumin-rich medium additional alanine aminopeptidase activity was found. Out of nine plasmodial proteases four were found in amoebae too. Only one band (pI 3.6) was present in the protein-poor medium. No protease activity could be detected in the proteinrich medium.
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  • 54
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    Archives of microbiology 114 (1977), S. 123-136 
    ISSN: 1432-072X
    Keywords: Fungus ; Cytochemistry ; Microbodies ; Development ; Entophlyctis
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    Topics: Biology
    Notes: Abstract Ultrastructural localization of peroxidatic activity was investigated in the chytrid Entophlyctis variabilis with the 3,3′-diaminobenzidine (DAB) cytochemical prodedure. The subcellular distribution of reaction product varied with changes in pH of the DAB medium and with the developmental stage of the fungus. Incubations in the DAB reaction medium at pH 9.2 produced an electron dense reaction product within single membrane bounded organelles which resembled microbodies but which varied in shapes from elongate to oval. At this pH the cell wall also stained darkly. When the pH of the DAB medium was lowered to pH 8.2 or 7.0, DAB oxidation product was localized within mitochondrial cristae as well as in microbodies and zoosporangial walls. As soon as zoospores were completely cleaved out of the zoosporangial cytoplasm, endoplasmic reticulum (ER) also stained. When the wall appeared around the encysted zoospore, ER staining was no longer found. The influence of the catalase inhibitor, aminotriazole, and the inhibitors of heme enzymes, sodium azide and sodium cyanide, on the staining patterns within cells incubated in the DAB media indicates that microbody staining is due to both catalase and peroxidase, mitochondrial staining is due to cytochrome c, and ER staining is due to peroxidase.
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    Archives of microbiology 134 (1983), S. 314-319 
    ISSN: 1432-072X
    Keywords: Antheridiol ; RNA Polymerase II ; Development ; ELISA ; Achlya ; Transcriptional regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The fungus, Achlya, is one of the most primitive eukaryotes known to secrete and respond to diffusible steroid sex hormones (pheromones). Antheridiol, which is produced by female strains of Achlya induces male strains to differentiate male sex organs. Induction of male strains with antheridiol elicits several changes in macromolecular synthesis including a quantitative enhancement in the synthesis of poly adenylated messenger RNA. We have examined whether this quantitative change is due to the regulation of RNA polymerase II. The level of polymerase increases as a response to the pheromone. This was examined using two different approaches, one of which included an extremely sensitive enzyme-linked immunosorbant assay (ELISA). Furthermore, the specific activities of polymerase II preparations isolated from pheromone-stimulated cultures was significantly higher than the specific activities of enzyme preparations isolated from control. A comparison of the polypeptide subunit composition of polymerase II preparations isolated from both pheromone-treated and control cultures on SDS polyacrylamide gels indicated no qualitative differences. Apparent differences in the stoichiometry of two specific subunits were reproducibly observed. The subunits of 140,000 and of 69,000 stained much more intensely in RNA polymerase II preparations isolated from 4h antheridiol-treated cultures.
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  • 56
    ISSN: 1432-072X
    Keywords: Rhodopseudomonas sphaeroides ; Continuous culture ; Control ; Bacteriochlorophyll ; Pigment protein complexes ; 5-Aminolevulinic acid ; Development ; Light
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Rhodopseudomonas sphaeroides mutant H5 lacking 5-aminolevulinic acid synthase was employed to study the control of the formation of total bacteriochlorophyll as well as of the B875- and B850-bacteriochlorophyll protein complexes. The organisms were grown phototrophically in a chemostat where cell protein formation was limited by iron ions and bacteriochlorophyll by 5-aminolevulinic acid. 0.07 mol of bacteriochlorophyll was formed per mol of 5-aminolevulinic acid consumed. This stoichiometric relationship was not influenced by a twelve-fold variation in light energy flux. However, cell protein levels increased and, consequently, cellular specific bacteriochlorophyll contents decreased with increases in light energy flux. The ratio of B875- to B850-pigment protein complexes was inversely proportional to the velocity of 5-aminolevulinic acid supply (mol per cell protein and time) which in this system equals the velocity of 5-aminolevulinic acid consumption and the velocity of bacteriochlorophyll formation. Light had no direct effect on the ratio of B875- per B850-pigment complexes but an indirect effect via its control of protein formation. Changes in the ratio of the two pigment complexes resulted from the fact that significantly lower amounts of 5-aminolevulinic acid supplied per protein and time were required to saturate the system assembling the B875-complexes than that assembling the B850-complexes. The data suggest lack of light-dependent control in the formation of bacteriochlorophyll and its complexes subsequent to the 5-aminolevulinic acid pool.
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  • 57
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    Planta 156 (1982), S. 496-504 
    ISSN: 1432-2048
    Keywords: Development ; Glandular scale ; Origanum dictamnus ; Secretion
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    Topics: Biology
    Notes: Abstract Glandular scales of Origanum dictamnus L. originate from a single protodermal cell. They are composed of a 12-celled head and an unicellular stalk and foot. During the early stages of gland differentiation, the head cells possess a small number of plastids which contain globular inclusions. Similar inclusions are also observed in the plastids of the stalk and the foot cell. The lateral walls of the stalk cell progressively undergo cutinization which does not extend to the upper and lower periclinal walls. At the onset of secretion the electron density of the plasmalemma region lining the apical walls of the head cells remarkably increases. These walls are impregnated with an osmiophilic substance identical in appearance to the content of the subcuticular space. In a following stage of the secretory process osmiophilic droplets of various size arise in the cytoplasm of the secretory cells which undergoes simultaneously a reduction of its initial density. After secretion has been concluded the protoplast of the head cells becomes gradually degenerated. The chlorenchyma cells of the mesophyll possess numerous microbodies closely associated with various organelles. In the cytoplasm of these cells crystalloids occasionally occur.
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    Theoretical and applied genetics 52 (1978), S. 269-271 
    ISSN: 1432-2242
    Keywords: Daphnia Pulex ; Development ; Sex Determination ; Ecological factors ; Identical Chromosome Sets
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Sex-dependent differences in the state of the nuclear chromatin of somatic cells were found in Daphnia pulex. It is suggested that the genome of Daphnia pulex has two developmental programmes based on identical chromosome sets. The female programme consistently functions under a wide range of ecological conditions, whereas the male programme is turned on by specific ecological stimuli. The genes controlling the activation and function of the male programme may be phenotypically latent for many parthenogenetic generations.
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  • 59
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    Cell & tissue research 108 (1970), S. 380-396 
    ISSN: 1432-0878
    Keywords: Epicuticle ; Insects ; Tenebrio molitor ; Development ; Structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'épicuticule de l'adulte de Tenebrio molitor est composée de deux couches distinctes dénommées épicuticule externe et épicuticule interne. L'épicuticule externe est la première couche cuticulaire sécrétée sous forme de petites plaques s'agrandissant par leurs bords pour recouvrir toute la surface cellulaire. Au moment de sa sécrétion, cette couche est formée de quatre lames denses A, B, C1 et C2. La lame B, très fine, disparaît par la suite et les lames C1 et C2 deviennent très nettes. L'épicuticule externe de l'adulte est donc formée de trois lames denses séparées par deux lames claires. L'épicuticule interne est formée de lames superposées denses et claires de structure complexe, qui sont masquées pendant la sécrétion des premières couches de cuticule lamellée (procuticule). Cette structure correspond à un arrangement moléculaire hautement organisé. La forme de la surface cuticulaire des sternites est déterminée par la forme de la surface cellulaire avant le dépôt de l'épicuticule.
    Notes: Summary The epicuticle of adult Tenebrio consists of two distinct layers named outer and inner epicuticle. The outer epicuticle is the first cuticular layer to be deposited in form of small patches on top of the microvilli. These initial patches are composed of four dense laminae (A, B, C1 and C2) separated by three light spaces. The outer epicuticle grows by densification of diffuse material at the edges of the patches until the entire area is covered. The thickness of outer epicuticle remains constant (175 Å) during the development of the pharate adult, lamina B however rapidly disappears. Thus, the adult outer epicuticle is fivelayered (three dense laminae: A, C1 and C2). After being deposited, the inner epicuticle shows a complex laminar structure interpreted to represent a highly organized molecular system. The laminae are masked during the formation of the first procuticle lamellae. During the deposition of the epicuticle, lamina A is covered by a component of the moulting fluid, forming an irregular dense layer which disappears after the resorption of this fluid. Perhaps this layer protects the new epicuticle from lytic enzymes of the moulting fluid. In adult animals, there is an additional superficial layer, the signification of which is not clear. The possibility of remains of cement or wax is discussed. The development of the surface patterns of the sternal and pleural cuticle is determined before the epicuticle formation by the shape of the epidermal surface. The rate of outer epicuticle deposition appears to depend on the size of the microvilli: epicuticle deposition seems to proceed faster over high microvilli.
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    Cell & tissue research 109 (1970), S. 1-14 
    ISSN: 1432-0878
    Keywords: Seminal vesicle ; Prostate ; Fetal rat ; Ultrastructure ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the seminal vesicle from the Wolffian duct and of the prostate from the urogenital sinus has been studied in rat fetuses from day 14 of gestation to birth with the use of the electron microscope. Prior to the onset of androgen secretion, the cells of the urogenital sinus and the caudal part of the Wolffian duct have a simple undifferentiated appearance. After the onset of androgen secretion by the fetal testes at day 15, “intracytoplasmic confronting cisternae” of the granular reticulum appear in both urogenital sinus and Wolffian duct. Portions of the granular endoplasmic reticulum of the urogenital sinus become distended with a finely granular, moderately dense material. In the urogenital sinus, many hemidesmosomes are formed at the basal surface of the epithelium. Specializations of the extracellular materials are present opposite the hemidesmosomes. The formation of the seminal vesicles and the prostate begins at day 18–19 of gestation. The cells of the seminal vesicle are taller than the Wolffian duct cells from which they arise, the granular endoplasmic reticulum increases moderately in amount, and a patent lumen is formed. The cells of the fetal prostate do not differ greatly from those of the urogenital sinus from which they arise except that the prostatic cells initially lack hemidesmosomes. The fine structural changes are discussed in relation to the onset of fetal androgen secretion, the formation of the organs, and the functions of the cells in adult life.
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    Cell & tissue research 111 (1970), S. 346-363 
    ISSN: 1432-0878
    Keywords: Kidney ; Glomerulus ; Development ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Differenzierung der Podocyten wurde an Nieren 10 Tage alter Ratten raster-elektronenmikroskopisch untersucht und mit durchstrahlungs-elektronenmikroskopischen Befunden verglichen. Die Podocytenfortsätze können danach auf dreierlei Wegen gebildet werden: 1. Spalten innerhalb des Cytoplasmas lassen bandartige Cytoplasmabrücken entstehen. Diese gliedern sich weiter auf, bis zahlreiche miteinander verzahnte Fortsätze derselben Zelle entstanden sind. 2. Vom Zellrand her werden dicke Fortsätze weit vorgeschoben, die kleinere Fortsätze bilden. Durch sie können Verzahnungen mit entfernten Deckzellen entstehen. Die kleinen Fortsätze können sich jedoch auch mit anderen Fortsätzen der eigenen Zelle verzahnen. 3. Fingerförmige Fortsätze benachbarter Zellen verzahnen sich während ihrer Entstehung miteinander. Trotz zahlreicher desmosomenartiger Haftstellen zwischen benachbarten Podocyten entwickeln sich ihre Fortsätze und deren Verzahnungen anscheinend weitgehend autonom und nur selten nach den vermuteten Regeln epithelialer Nachbarschaft (Typ 3). Die Befunde sprechen vielmehr dafür, daß durchflutete und wachsende Glomerulumkapillaren die Podocytendifferenzierung induzieren und die Orientierung der Fortsätze beeinflussen.
    Notes: Summary The differentiation of the podocytes was studied by scanning electron microscopy on kidneys of 10 days old rats. The results were compared with transmission electron microscopic pictures from the same kidneys. There are three ways of forming processes by the podocytes: 1. Slits within the cytoplasm give rise to cytoplasmic bridges which further divide themselves and finally build up a meshwork of processes within a cell. 2. Thick and sometimes very long processes originate from the cell border. Their smaller branches may interdigitate with those of distant podocytes or with other processes out of the same cell. 3. Finger-like processes of neighbouring cells interdigitate as soon as they develop. In spite of numerous desmosomal structures between neighbouring podocytes the cell processes and their interdigitations develop mostly independently from each other and only seldom after the expected rules of epithelial vicinity (type 3). These findings are interpreted as indication that flooded and growing capillaries induce the differentiation of podocytes and that they influence the orientation of their processes.
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  • 62
    ISSN: 1432-0878
    Keywords: Chemoreceptor ; Locusta ; Fine structure ; Development ; Moulting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The basic structure of the terminal sensilla of Locusta migratoria resembles that of Schistocerca gregaria. There are commonly six or ten neurons whose dendrites extend almost to the opening of the peg. Proximally the dendrites are clothed by a neurilemma cell which also encloses a basal cavity through which their ciliary region passes. The tormogen cell encloses the receptor-lymph cavity and actively secretes material into it. The receptor-lymph cavity and the basal cavity are quite separate. The development of new pegs at a moult is described. After apolysis the scolopale extends across the subcuticular space and protects the dendrites, which remain in a functional condition until shortly before ecdysis. As the trichogen cell grows out to form a new peg the tip is surrounded by a mass of electron-dense material, probably derived from the receptorlymph cavity. The function of this material is unknown. Regeneration of the dendrites is considered. The possible mechanism by which the tip of the peg opens and closes is considered and the general structure of the organule is discussed in relation to functioning.
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    Cell & tissue research 200 (1979), S. 223-227 
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Lacertilian reptiles ; Vasotocin neurons ; Mesotocin neurons ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The hypothalamic magnocellular neurosecretory system of lizards was studied with the unlabeled antibody peroxidase-antiperoxidase complex (PAP) technique at the light microscopic level. It was shown that vasotocin and mesotocin are synthesized in separate neurons. The vasotocinergic as well as the mesotocinergic perikarya are of different sizes. Both cell types occur in close juxtaposition, but without a distinct pattern of distribution. The external zone of the lacertilian median eminence contains numerous immunoreactive vasotocinergic fibers and only few immunoreactive mesotocinergic fibers. The general organization of the hypothalamic magnocellular neurosecretory system of lizards, as revealed by immunocytochemistry, is essentially similar to that revealed with unspecific staining methods.
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  • 64
    ISSN: 1432-0878
    Keywords: Immunocytochemistry ; Ecdysteroids ; Prothoracic gland ; Insect hormones ; Galleria mellonella
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    Topics: Biology , Medicine
    Notes: Summary Fixation of prothoracic glands of Galleria mellonella with a solution containing saponin permits immunocytochemical staining of the entire gland. By this means ecdysteroids were demonstrated electron microscopically to be present in the hyaloplasm and microtubules.
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  • 65
    ISSN: 1432-0878
    Keywords: Nervous system ; Stick insect ; Blood-brain barrier ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
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    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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    Cell & tissue research 106 (1970), S. 348-370 
    ISSN: 1432-0878
    Keywords: Ovary ; Insect ; Chironomus ; Development ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Im Ovar von Chironomus sind in Phase 1 des 4. Larvenstadiums polygonal abgeflachte „Innenzellen“ von kleineren „Außenzellen“ umgeben, die Bakteroide und Phagosomen enthalten; zwischen den Innenzellen liegen unregelmäßige Zelltrümmer („keimbahnbegleitende Substanzen“). Zu Beginn der Ovariolenbildung werden in Phase 3 durch Spalträume zwei Schichten der Außenzellen voneinander getrennt, von denen die innere (Follikel- und Eikanalepithel) regelmäßige Buchten bildet. In diese Buchten wandern von innen Zellpaare ein, die an „synaptischen Komplexen“ bzw. multiplen Chromatinstrukturen als Ei- und Nährzellen kenntlich sind. Zwischen beiden Zellen sind „Fusome“ häufig, die später in eigentümlicher Weise geschlossen werden. Zwischen den Eikanalzellen entsteht in Phase 5 durch Spaltbildung der Eikanal; in Phase 7 sind die Eikanalzellen auffallend glykogenreich. Kurz vor der Vitellogenese treten im Bereich der Oocyte Membransysteme und „annulated lamellae“ auf; akzessorische Kerne werden als Ausstülpungen des Oocytenkernes gebildet und später abgeschnürt. In Phase 9 sind an der Peripherie der Eizelle Mikrovillisäume und Pinocytosebläschen sichtbar. Die distalen Zellen der Ovariole haben Eioder Nährzellcharakter, sind aber bei Ch. melanotus nicht von Follikelzellen umgeben und werden beim weiteren Ovariolenwachstum reduziert. Trotz extrem geringer Nährzellzahl der Follikel scheint das Chironomus-Ovar funktionell nicht von anderen polytroph meroistischen Insektenovarien unterschieden.
    Notes: Summary In the ovary of Chironomus during phase 1 of the fourth larval instar, polygonally flattened “inner cells” are surrounded by smaller “outer cells” which contain bacteroids and phagosomes. Irregular cell remnants (“germ line accompanying substances”) lie among the inner cells. At the beginning of ovariole formation in phase 3, two layers of outer cells are separated by the formation of fissures. The inner layer of these cells (follicle- and egg-passage epithelium) forms regular invaginations. Cell pairs, identified as oocytes and nurse cells by “synaptic complexes” or multiple chromatin structures, wander from inside into the invaginations. Frequently between the two cells are fusomes, which later close in a characteristic manner. During phase 5, an egg passage is formed as a fissure among the egg-passage cells. During phase 7, the egg passage cells are conspicuously full of glycogen. Shortly before vitellogenesis membrane systems and annulated lamellae appear in the region of the oocyte. Accessory nuclei are formed by a “tieing-off” of projections of the the oocyte nucleus. During phase 9, microvilli and pinocytotic vesicles can be seen at the periphery of the oocyte. The distal cells of the ovariole are of oocyte or nurse cell nature, but in Ch. melanotus they are not surrounded by follicle cells and are reduced during further ovariole growth. In spite of the extremely small number of nurse cells in the follicle, the Chironomus ovary apparently does not differ functionally from other polytrophic meroistic insect ovaries.
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    Cell & tissue research 147 (1973), S. 75-85 
    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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    Cell & tissue research 147 (1974), S. 325-334 
    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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    Cell & tissue research 148 (1974), S. 535-550 
    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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    Cell & tissue research 144 (1973), S. 435-452 
    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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    Cell & tissue research 150 (1974), S. 425-442 
    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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    Cell & tissue research 151 (1974), S. 433-456 
    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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  • 73
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    Cell & tissue research 153 (1974), S. 115-136 
    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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  • 74
    ISSN: 1432-0878
    Keywords: Luteinizing hormone-releasing hormone ; Hypothalamus ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Utilizing the unlabeled antibody enzyme method, we report the distribution of hypothalamic elements immunoreactive with antibodies to luteinizing hormone-releasing hormone (LH-RH) in the rat. Immunostained elements, resembling neural processes, were distributed along a pathway corresponding to the tuberoinfundibular tract which appeared to terminate near vascular elements in the external layer of the preand post-infundibular median eminence. No cell bodies stained specifically for LH-RH. Similar topographic arrangements were noted (in coronal and sagittal sections) in diestrous females, ovariectomized females and a hypophysectomized male. The same results were obtained with three different preparations of antisera to LH-RH. Our studies agree with those of other investigators using immunohistochemical techniques as well as with localization studies of LH-RH in the hypothalamus using bioassay and radioimmunoassay. Our results suggest that the unlabeled antibody enzyme technique will have unique value for identifying and tracing fiber systems related to specific functions within the hypothalamus.
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  • 75
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    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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  • 76
    ISSN: 1432-0878
    Keywords: Submandibular gland (mice) ; Sex-dimorphism ; Amylase ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The submandibular glands of developing and mature Strong A mice were studied by light and electron microscopy. The glands of both sexes show the same cell types during development, but during maturation the glands display a degree of sex-dimorphism. Striated ducts, which differentiate from the larger intralobular ducts present in the neonatal gland, first appear by 5 days of age and reach their mature condition by 20 days of age. Granular convoluted tubule cells, which differentiate from striated duct cells, are first seen at 15 days of age in both sexes. Subsequently, they show a more rapid development in males than in females, and are dimorphically represented by 20 days of age. Intercalated ducts in the neonatal gland contain nongranular and granular cells. With maturation the number of granular cells decreases, apparently due to their conversion into the nongranular type, with their eventual disappearance from the glands of adult males. Their retention in adult females further defines the sexual dimorphism shown by these glands. Amylase activity in gland homogenates is first detectable at 20 days of age in both sexes. During development the male glands show a rapid rise in levels of amylase activity, whereas female glands show a more gradual rise. In mature animals, male glands have higher levels of amylase activity than female glands. The developmental and adult status of amylase activity parallels that of the granular convoluted tubules.
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  • 77
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    Cell & tissue research 159 (1975), S. 195-204 
    ISSN: 1432-0878
    Keywords: Subcommissural organ ; Neurons ; Development ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neurons which initially lie in the basal region of the subcommissural organ (SCO) were investigated in 20 rabbit fetuses from day 15 to 30 of gestation, and in eight neonatal, 4 and 8 day old rabbits. These SCO-associated neurons, first observed on day 17 of gestation, develop into (1) a rostral mesodiencephalic nerve cell group situated in an area dorsal to the rostral-most part of the SCO and (2) a more caudal layer of single neurons extending throughout the length of the SCO. The present findings are discussed in relation to recent histochemical studies that demonstrated AChE-positive neurons in the pineal complex and subcommissural area of frogs and to recent fluorescence microscopic studies in fetal and adult rats in which a 5-HT system is known to extend from the nucleus raphe dorsalis (B7) along the SCO to the pineal stalk and habenular region. The term “SCO-associated neurons” is a purely morphological way of describing the neurons in question as the neural interconnections of these neurons are still a matter of speculation.
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  • 78
    ISSN: 1432-0878
    Keywords: Neuromuscular junctions ; Rete synapticum ; Development ; Antheraea ; (Lepidoptera) ; Trophic action ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of neuromuscular connections on developing dorsolongitudinal flight muscles was studied in the moth Antheraea polyphemus, Undifferentiated membrane contacts between axon terminals and muscle-fiber anlagen are present in the diapause pupa. They persist during the period of nerve outgrowth, which probably provides a pathway of contact guidance. By the 4th day of adult development some of these contact areas have differentiated into structures similar to neuromuscular junctions although differentiation of muscle structure does not start earlier than the eighth day. Dense-cored vesicles are abundant in many axon terminals at the beginning of development. They later decrease in number quite rapidly. The significance of the above-mentioned early junctions, their possible mode of action and the role of the dense-cored vesicles are discussed. It is proposed that they exercise a stimulating (trophic) influence on the growth of the undifferentiated muscular tissue. The imaginai neuromuscular junctions are formed during the second half of adult development. Clusters of vesicles and electron-dense depositions along the inner face of the axolemma seem to initiate junction formation. Glial processes then grow between axoand sarcolemma and divide the large contact area into several small segments. Mutual invaginations and protrusions of the sarcolemma and the glial cell membrane subsequently form an extensive “rete synapticum.” Six days before eclosion the glial and sarcoplasmic parts of the rete synapticum are similar in size. Up to eclosion, all glial processes shrink and increase in electron density. Most of the observations are discussed also in relation to findings in vertebrates.
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  • 79
    ISSN: 1432-0878
    Keywords: Ovary, dog ; Corpus luteum ; Development ; High voltage electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The transition from ovarian granulosa to lutein cell during the estrus cycle of 60 pregnant and non-pregnant beagle bitches was analyzed by light and electron microscopy (both 100 and 1000 KV). Early proestrus was characterized by a gradual rise in serum estrogen levels, hyperplasia of the granulosa cells, the accumulation of follicular fluid, and the development of tortuous intercellular channels. During the second half of proestrus, serum estrogen levels continued to rise, but growth, division, and differentiation of the granulosa cells was minimal. Estrus was marked by the first acceptance of the male and a well-defined LH peak In the subsequent 24 hour period, the granulosa-lutein cells hypertrophy rapidly and develop a large Golgi apparatus, small profiles of granular endoplasmic reticulum, numerous microfilaments, and large gap junctions between the cells. Mitochondria also proliferate, enlarge, and elongate, but retain lamelliform cristae. Luteinization of the cells and progesterone secretion begin just after ovulation which in turn occurs about 24 hours after the LH peak. On the third and fourth day of estrus, numerous small vesicles of agranular endoplasmic reticulum fill the cytoplasm and the mitochondria swell up and round off. The vesicles rapidly fuse into whorled and flattened cisternae or anastomosing tubules of agranular endoplasmic reticulum, while the mitochondria develop tubulovesicular cristae. These structures gradually become organized with respect to the basal lamina. The Golgi apparatus is centered over the pole of the nucleus that faces the pericapillary space. Stacked and whorled cisternae of agranular ER develop in the lateral margins and avascular end of the cell while mitochondria and tubular elements of agranular ER predominate in the central medial and most basal portions of the cytoplasm. Microfilaments are ubiquitous and appear to be instrumental in this orientation process. The cell surface develops three distinct regional specializations that coincide with the underlying cellular compartment: interconnecting pleomorphic folds fill the pericapillary space; long tenous microvilli project from the lateral cell surface and form tortuous intercellular channels and canaliculi; and large gap junctions form along the margins of the cell furthest removed from the basal lamina. By the sixth day of estrus, the granulosa-luteal cell transition is nearly complete and serum progesterone levels are on the rise.
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  • 80
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    Cell & tissue research 176 (1977), S. 167-178 
    ISSN: 1432-0878
    Keywords: Intestine (rat) ; Development ; Isolated cells ; Enzymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A modification of Weiser's (1973) cell isolation method was used in order to study the developmental pattern of various intestinal enzyme activities in villus and crypt cells of normal rats from 5 days after birth until 8 weeks. Alkaline phosphatase and enterokinase activities were always located in the upper villus zone during postnatal development. Enterokinase activity was higher in the upper villus cells during the third week of life than after this period. Aminopeptidase activity was located in the crypt cells during the first week, its maximum activity remained in this area until the third week. At this time, sucrase activity appeared in the crypt cells, then aminopeptidase and sucrase activities rose to the villus zone during the fourth week. Amylase activity was detected along the entire crypt-villus axis 5 days after birth, reaching maximum activity in crypt cells at the end of the first week and in the upper villus cells after the fourth week. In contrast with the other enzymes studied almost all amylase activity was soluble in the youngest animals whereas at weaning most of the activity appeared in a particulate form in the villus cells. But in the crypt cells the ratio between particulate and soluble form remained unchanged until the adult stage. Various hypotheses are advanced to explain the patterns of evolution of the different enzymes.
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  • 81
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    Cell & tissue research 167 (1976), S. 265-288 
    ISSN: 1432-0878
    Keywords: Myelinated fibres ; Visual cortex ; Stereology ; Development ; Electron microscopy ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary With the aid of stereological procedures the development of myelinated nerve fibres (MF) was quantitatively investigated in electron micrographs of the visual cortex from animals of different ages: 36 days-old, the age at which fibres first appear, through adulthood. A short description of tissue treatment, methods and qualitative results is given. The following quantitative results are presented: 1. Myelinization begins at about the 36th day postpartum and is not completed by the 164th day. At this time a lack of about 20% MF can be observed. 2. The average diameter of MF decreases from 1.3 μm to 0.8 μm from day 36 to adulthood. 3. The first MF appear near the border of the album. 4. Beginning with the 55th day, small MF arise in layer I, showing two periods of growth. 5. The maximum MF density in the region of layer IV corresponds to the strip of Baillarger. Other aspects of visual cortex development are dealt with in the Discussion. The following conclusions can be drawn: a) The growing of inand output-MF is completed first. b) The development of the internal connecting systems in layers I and IV begins a little later and is completed by the 5th month. c) The MF in layers II and III appear after the 4th month. Kaes (1907) has also described a continuation of MF growth in man lasting into the twenties.
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  • 82
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    Cell & tissue research 137 (1973), S. 251-269 
    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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  • 83
    ISSN: 1432-0878
    Keywords: Enkephalin neurons ; Vasotocin neurons ; Isotocin neurons ; Immunocytochemistry ; Goldfish (Carassius)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Our immunocytochemical investigation of the magnocellular neuroendocrine system in the goldfish hypothalamus reveals enkephalin (ENK)-containing neurons interspersed among the vasotocin (VT)- and isotocin (IT)-containing neurons of the preoptic nucleus. The perikarya of the ENK, VT, and IT neurons do not show distinct morphological differences at the level of light microscopy and are not located preferentially within the nucleus. Separate ENK, VT and IT fibers course laterally and ventrally through the hypothalamus as they descend toward the pituitary gland. All three fiber types form terminals around blood vessels in the neurohypophysis.
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  • 84
    ISSN: 1432-0878
    Keywords: Pancreatic polypeptide (PP) ; Neurones ; Central nervous system ; Peripheral nervous system, gut ; Immunocytochemistry ; Mammals ; Birds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pancreatic polypeptide (PP) is a candidate hormone of unknown physiological significance. It is produced by a population of endocrine cells in the pancreas. In the present study a PP-like peptide was found to occur in the mammalian and avian central and peripheral nervous systems. Immunoreactive nerve fibres and nerve cell bodies were widely distributed in the brain. Dense accumulations of nerve fibres occurred in the following areas: nucleus accumbens, interstitial nucleus of the stria terminalis, para- and periventricular hypothalamic nuclei, and medial preoptic area. In addition, nerve fibres were regularly seen in cortical areas. Immunoreactive perikarya were observed in the following regions: cortex, nucleus accumbens, neostriatum and septum. In the gut, immunoreactive nerve fibers were distributed in the myenteric plexus, in smooth muscle, around blood vessels, and in the core of the villi. Immunoreactive perikarya occurred in the submucosal and myenteric plexus, suggesting that PP immunoreactive nerves are intrinsic to the gut. In the species examined, the neuronal PP-like peptide could be demonstrated with an antiserum raised against avian PP, but not with those raised against bovine or human PP. Thus, neuronal PP is distinct from the PP that occurs in pancreatic endocrine cells.
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  • 85
    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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  • 86
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    Cell & tissue research 150 (1974), S. 481-492 
    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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  • 87
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    Cell & tissue research 151 (1974), S. 509-523 
    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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    Cell & tissue research 152 (1974), S. 13-30 
    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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  • 89
    ISSN: 1432-0878
    Keywords: Pituitary ; Dexamethasone ; ACTH ; Autoradiography ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 3H-Dexamethasone (10 μg/kg) was injected intravenously in adrenalectomized rats and after survival times of 5, 30, 60, and 180 min its uptake within the pituitary was studied by autoradiography. Radioactivity was concentrated in cell nuclei in the pars nervosa and pars distalis. Within the pars intermedia, only cells of the marginal zone were labeled. In the pars distalis, some cells showed a weak nuclear accumulation of radioactivity as early as 5 min after injection. The tissue radioactivity was nearly maximal at 5 min, and the proportion of radioactivity in nuclei reached a maximum of 60–70% by 30 min. In competition experiments, non-radioactive steroids (1 mg/kg) were injected 5 min before 3H-dexamethasone and sacrifice was 30 min later. Dexamethasone markedly diminished the nuclear accumulation in the pars distalis, but corticosterone and progesterone did not. In the pars nervosa, corticosterone and progesterone competed for nuclear uptake of 3H-dexamethasone, although less effectively than dexamethasone itself. Different cell types in the pars distalis were characterized by treating autoradiograms with an immuno-peroxidase bridge procedure. Cells treated with anti-ACTH 17–39 had the greatest nuclear concentration of radioactivity, and those stained with anti-TSH were least heavily labeled. Cells treated with antisera to GH, PRL, and hCG were moderately labeled.
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  • 90
    ISSN: 1432-0878
    Keywords: Rat posterior pituitary ; Neurophysin-vasopressinergic and neurophysin-oxytocinergic fibres ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By means of the unlabeled antibody peroxidase-antiperoxidase (PAP) technique at the electron microscopic level, it was demonstrated that the hormones of the neural lobe of the rat hypophysis are located in separate neurophysin-vasopressinergic and neurophysin-oxytocinergic nerve fibres. These observations confirm the results of our previous immunocytochemical studies at the light microscopic level.
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  • 91
    ISSN: 1432-0878
    Keywords: Growth hormone-release inhibiting hormone ; Somatostatin ; Hypothalamus ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary Utilizing the unlabeled antibody enzyme method, we investigated the distribution of hypothalamic elements immunoreactive with antibodies to growth hormonerelease inhibiting hormone (GH-RIH). Immunostained elements, resembling neural processes, are distributed along a pathway corresponding to a portion of the tuberoinfundibular tract. However, GH-RIH fibers are caudal, dorsal and medial to LH-RH fibers detected by the same technique. Similar topographic arrangements are noted in coronal and sagittal sections. Comparable results were obtained with two different preparations of antisera to GH-RIH. No cell bodies specifically stained by anti-GH-RIH were detected. Our data agree with those of other investigators using immunohistochemical techniques.
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  • 92
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Cell types ; Estrogen ; Autoradiography ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dry-mount autoradiography was combined with peroxidase immunocytochemistry to examine estrogen uptake in four pituitary cell types. Quantification by silver grain counts was used to compare 3H-estradiol uptake in nuclei of pituitary cells 60 min after i.v. injection into short-term (control) and long-term ovariectomized and in long-term thyroidectomized rats. Under all three hormonal states, the order of labeling intensity was: gonadotropes 〉 somatotropes 〉 lactotropes 〉 thyrotropes. Long-term ovariectomy caused a significant increase in estrogen uptake of gonadotropes, somatotropes and lactotropes, while uptake in thyrotropes decreased. Long-term thyroidectomy decreased uptake in somatotropes, lactotropes and thyrotropes while gonadotropes remained unchanged.
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  • 93
    ISSN: 1432-0878
    Keywords: Nerve growth factor ; Submandibular gland mice ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Nerve growth factor (NGF) was localized in the submandibular gland of adult male mice by a direct immunocytochemical method using highly purified antibodies against NGF coupled to horseradish peroxidase. In light microscopic sections the reaction product was entirely confined to the cells of the secretory tubules. The acinar part of the gland was free of reaction product. This finding was confirmed by electron microscopy. Within the cells NGF was localized exclusively in the apical secretory granules. No reaction was observed in the rough endoplasmic reticulum, the Golgi region or in the granules of the basal part of the cells. This observation favours the assumption that NGF is derived from a precursor molecule and that the precursor is transformed into immunologically active NGF within the secretory granules during their transport from the basal to the apical part of the tubular cells. Stimulation of the submandibular gland with carbachol (2 mg/kg) led to a massive release of the content of the secretory granules, including NGF, into the salivary duct.
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  • 94
    ISSN: 1432-0878
    Keywords: Luteinizing hormone-releasing hormone ; Median eminence ; Electron microscopy ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary LH-RH was localized at the ultrastructural level in axons and nerve terminals of the median eminence of the male guinea pig. LH-RH positive neuronal profiles were most concentrated in the medial-dorsal aspect of the infundibular stalk and in the post-infundibular median eminence at the level immediately following separation of the stalk from the base of the brain. LH-RH containing axon profiles were most abundant in the palisade zone; nerve terminals in contact with the hypophysial portal vasculature were relatively rare. The hormone was present within granules that measured 900–1,200 Å in axons of the palisade zone and 400–800 Å in nerve terminals abutting on the portal plexus. The differently sized granules represent heterogeneous populations.
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  • 95
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    Cell & tissue research 109 (1970), S. 138-146 
    ISSN: 1432-0878
    Keywords: Insect muscles ; Development ; Microtubuli ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung In der indirekten Flugmuskulatur von Phormia terrae-novae kann die Entwicklung der Myofibrillen deutlich in eine Anlage- und eine Wachstums-Phase unterteilt werden. Zu Beginn der Wachstumsphase wurde Puppen eine Lösung von Colchicin in die rechte Metathoraxhälfte injiziert. Als Folge dieser Behandlung lösten sich zunächst die Mikrotubuli in der Flugmuskulatur auf. In späteren Entwicklungsstadien bildeten sich atypische Verzweigungen der Myofibrillen, die zu einer partiellen Desorientierung der kontraktilen Strukturen führten. Ein Mechanismus, der solche Störungen des Orientierungmusters in der Normalentwicklung möglicherweise verhindert, wird diskutiert.
    Notes: Summary In the blowfly Phormia terrae-novae the development of myofibrils of indirect flight muscles can be divided into periods of predisposition (anlage) and of growth. At the beginning of the growth period microtubules are disrupted by injection of colchicine. This disruption is followed by the formation of atypical ramifications of myofibrils at Z-discs leading to numerous disoriented myofibrils in late developmental stages. A possible mechanism preventing these alterations during normal development is discussed.
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  • 96
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    Cell & tissue research 110 (1970), S. 72-84 
    ISSN: 1432-0878
    Keywords: Lung cells ; Chick embryo ; Lamellar inclusions ; Ultrastructure ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Les pneumocytes granuleux, qui constituent l'un des principaux types cellulaires de l'épithélium pulmonaire, sont caractérisés par la présence de volumineuses inclusions osmiophiles lamellaires. Nous avons étudié l'apparition et l'origine de ces inclusions dans l'épithélium du poumon embryonnaire de Poulet, en l'examinant à différents stades du développement. Les premières inclusions lamellaires apparaissent dans le poumon de l'embryon de 16 jours. A ce stade, quelques lamelles concentriques entourent une zône centrale amorphe étendue; la périphérie des inclusions contient toujours de petites structures granulaires. Les jours suivants le nombre de cellules contenant des inclusions lamellaires augmente rapidement; en même temps, les lamelles deviennent plus nombreuses. A 19 jours, les inclusions lamellaires ont un aspect semblable à celui qu'elles ont dans les poumons d'animaux adultes. Dès l'apparition des ébauches pulmonaires, à 2 1/2 jours d'incubation, les cellules épithéliales contiennent des inclusions typiques: les inclusions granulaires. Ces organites sont caractérisés par un centre granulaire, qu'entouré un système membranaire. Ce système, simple chez le jeune embryon, évolue ensuite en se compliquant; chez l'embryon de 16 jours, il s'enroule en plusieurs couches autour de la masse centrale. Au moment où les premières inclusions lamellaires apparaissent, le nombre des inclusions granulaires augmente rapidement; on les trouve souvent étroitement associées à des vacuoles lipidiques. L'analyse des relations entre inclusions lamellaires, inclusions granulaires et vacuoles lipidiques suggère que l'inclusion lamellaire résulte de la collaboration entre une vacuole lipidique et plusieurs inclusions granulaires.
    Notes: Summary The granular pneumocytes, one of the main cellular types of the lung epithelium, are characterized by the presence of large osmiophilic lamellar inclusions. The appearance and origin of these inclusions has been studied in the epithelium of chick embryonic lung at different developmental stages. Lamellar inclusions are first seen in the lung of 16 day old embryos. At this stage, few concentric lamellae surround a large amorphous center; the periphery of the inclusions always contains small granular structures. In the following days, the number of cells containing these lamellar inclusions increases rapidly, while their lamellae progressively become more numerous. In 19 day old embryos, the lamellar inclusions are similar to those in the lungs of adult animals. From the earliest formation of the bronchial primordia, their epithelial cells contain a number of typical “granular” inclusions. These organelles are characterized by a granular center, enclosed in a membranous system. This structure becomes more complex as the embryo develops; in the 16 day old embryo, the multilayered membranous system coils around the granular center. At the time when lamellar inclusions first appear, granular inclusions increase rapidly in number and are often found in close association with lipidic vacuoles. The relationships between lamellar inclusions, granular inclusions and lipidic vacuoles are discussed. The evidence suggests that a lamellar inclusion arises from the cooperation of several granular inclusions and a lipidic vacuole.
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  • 97
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    Cell & tissue research 113 (1971), S. 558-563 
    ISSN: 1432-0878
    Keywords: Pterin layer ; Pigmentation ; Dermis ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the pterin layer was investigated in both wild type Rana pipiens and Rana pipiens homozygous for the speckle mutant gene. No difference in morphology of the layer was noted between the wild type and mutant. The layer lines the outer surface of the stratum compactum of the dermis and separates this stratum from the stratum spongiosum. The pterin layer consists of extra-cellular material and contains membrane-bounded granules filled with fine spicules. Many of the spicules are somewhat similar in appearance to the initial calcification loci present in developing membrane bone. The layer first appears in the tadpole at approximately stage 14 (Taylor and Kollros, 1946); subsequent developmental stages are described.
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  • 98
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    Cell & tissue research 113 (1971), S. 157-173 
    ISSN: 1432-0878
    Keywords: Prostate ; Development ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The postnatal development of the rat prostate has been studied with the electron microscope. Major developmental changes begin during the second week after birth and involve organelles associated with the formation of secretions. The amount of granular endoplasmic reticulum and the size of the Golgi complex increase greatly. Large vacuoles that probably contain secretory material are formed, and the lumen of the prostatic acini appears to contain secreted material. Large lysosomes with polymorphic interiors are present as early as 10 days after birth, and they become numerous by the end of the third week. Differences in fine structure between the different lobes of the prostate are detectable in 10–14 day old rats. The subsequent differentiation of the granular endoplasmic reticulum into the forms characteristic of the different prostatic lobes is described. The initial changes in the prostate occur in advance of sexual maturity of the animal, and the adult appearance of the gland is attained by 4–5 weeks after birth.
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  • 99
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    Cell & tissue research 114 (1971), S. 546-556 
    ISSN: 1432-0878
    Keywords: Microvilli ; Small intestine ; Brush border ; Development ; Golgi apparatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Frage, auf welche Weise die Enterocyten des fetalen Rattendünndarms das für die Mikrovillibildung benötigte Membranmaterial liefern, wurde elektronenmikroskopisch untersucht. Es wird angenommen, daß hufeisenförmige Strukturen, die aus mit elektronendichtem Material bedeckten Elementarmembranen bestehen und möglicherweise Längsschnitten durch kappenförmige Gebilde entsprechen, in das apicale Plasmalemm eingebaut werden und für die Bildung der Mikrovillispitzen verantwortlich sind. Diese Annahme gründet sich in erster Linie auf die Feststellung eines nahezu identischen Durchmessers von „Hufeisen“ und Mikrovilli, auf die Lokalisation der „Hufeisen“ im Terminalgespinst und ihr zahlenmäßiges Verhalten während der Mikrovillibildung. Die „Hufeisen“ entstehen im Golgi-Apparat.
    Notes: Summary The origin of membranes required for the formation of microvilli has been investigated electronmicroscopically in enterocytes of fetal rat small intestine. It is assumed that horseshoe-like structures consisting of unit membranes covered with electron-dense material, which probably represent longitudinal sections through cap-like structures, are incorporated into the apical cell membrane and give rise to the tips of microvilli. This assumption is based chiefly on the almost identical diameters of “horseshoes” and microvilli, the localization of “horseshoes” in the terminal web, and the time of appearance and disappearance of “horseshoes” with regard to development of microvilli. There are indications that the “horseshoes” originate in the Golgi apparatus.
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  • 100
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    Cell & tissue research 115 (1971), S. 396-415 
    ISSN: 1432-0878
    Keywords: Human pineal organ ; Development ; Innervation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This investigation is concerned with pineal organs of human embryos 60 to 150 days old. At every stage central nerve fibres enter the pineal organ by way of the habenular commissure, but are restricted to the pineal's proximal part. On about the 60th day of the development the sympathetic nervus conarii grows into the distal pole of the pineal organ from a dorso-caudal direction and plays the predominant part in the innervation of the pineal organ. After penetrating, it soon branches out and forms a network in the pineal tissue. Much later, not until the 5th embryonic month, sympathetic nerves appear accompanying the supplying vessels in the perivascular spaces. After a short time these nerves pierce the outer limiting basement membrane and penetrate the parenchyma. Towards the end of the 5th embryonic month the axons of the sympathetic nerves form varicosities containing clear and dense core vesicles. At this point large amounts of laminated granules appear primarily in cell processes, probably of pinealocytes. Isolated granules also occur in the varicosities of axons. The granules encountered here are most likely secretory granules.
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