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  • Immunocytochemistry  (352)
  • Drosophila  (266)
  • Springer  (618)
  • Cell Press
  • 1985-1989  (353)
  • 1980-1984  (265)
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  • 1
    ISSN: 1432-1432
    Keywords: Drosophila ; Foldback element ; Transposable element
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Foldback elements are a family of transposable elements described inDrosophila melanogaster. The members of this dispersed repetitive family have terminal inverted repeats that sometimes flank a central region. The inverted repeats of all the family members are homologous. The study of the distribution and conservation of the foldback elements in differentDrosophila species shows that this distribution is different from that of the hybrid dysgenesis systems (PM and IR). Sequences homologous to foldback elements were observed by Southern blots and in situ hybridization in all species of themelanogaster subgroup and in some species of themontium andtakahashii subgroups. The element was probably already present before the radiation of these subgroups. No evidence of horizontal transmission of the foldback element could be observed.
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  • 2
    Electronic Resource
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    Springer
    Development genes and evolution 198 (1989), S. 227-232 
    ISSN: 1432-041X
    Keywords: Campaniform sensilla ; Drosophila ; Achaete-scute complex ; Cis regulatory sites
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have analysed the role of the achaete-scute gene complex in the development of the pattern of campaniform sensilla on the wing blade of Drosophila. We show that the complete pattern results from the superimposition of two independent subpatterns, one of which depends on the achaete gene and the other on scute. The scute subpattern comprises several clusters of sensilla, most of which seem to require the presence of control regions located upstream of the transcribed region. This is in contrast with the pattern of scute-dependent bristles, most of which depends on control elements located downstream of the transcribed region.
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  • 3
    Electronic Resource
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    Springer
    Development genes and evolution 198 (1989), S. 65-77 
    ISSN: 1432-041X
    Keywords: Cell communication ; Pattern formation ; Cell differentiation ; trans-regulatory genes ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The effects ofpolyhomeotic (ph) mutants in imaginal cells have been studied in a clonal analysis. Clones of cells, homozygous forph, sort-out after a few divisions, probably as a consequence of modified cell affinities. The dorso-ventral margin of the wing has special characteristics that retard this phenomenon. The formation and exclusion of a clone of 8–16 cells affect the polarity of the wild-type neighbour cells and can provoke pattern triplications. The results suggest that a defect in intercellular communication prevents the wild-type cells from maintaining coordinated positional information. The cells react by regenerative growth, and reorganize into a new pattern. The pleiotropic phenotypes ofph mutants are explained according to a common hypothesis aboutph + function.
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  • 4
    Electronic Resource
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    Springer
    Development genes and evolution 198 (1989), S. 157-169 
    ISSN: 1432-041X
    Keywords: Distal less ; Limb development ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The development of all of the adult limbs inDrosophila depends upon the activity of theDistal-less gene. We report here the phenotypic characterization of a number of hypomorphicDistal-less alleles which indicates that there is a graded requirement forDistal-less activity in the developing limbs. Previous analysis of genetically mosaic animals indicated that cells in the early primordia of the limb imaginal dises possess a graded proximal-distal positional information which depends on the presence of theDistal-less gene for its expression. Taken together these data suggest thatDistal-less may directly encode the graded positional information that is required to organise the proximal-distal axis of the developing limbs.
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  • 5
    Electronic Resource
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    Springer
    Development genes and evolution 198 (1989), S. 185-190 
    ISSN: 1432-041X
    Keywords: Drosophila ; Oogenesis ; Follicle cells ; Egg shell ; Ovarian tumor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The developmental potential of the cells of the somatic follicular epithelium (follicle cells) was studied in mutants in which the differentiation of the germ-line cells is blocked at different stages of oogenesis. In two mutants, sn 36a and kelch, nurse cell regression does not occur, yet the follicle cells around the small oocyte continue their normal developmental program and produce an egg shell with micropylar cone and often deformed operculum and respiratory appendages. Neither the influx of nurse cell cytoplasm into the oocyte nor the few follicle cells covering the nurse cells are apparently required for the formation of the egg shell. In the tumor mutant benign gonial cell neoplasm (bgcn) the follicle cells can also differentiate to some extent although the germ-line cells remain morphologically undifferentiated. Vitelline membrane material was synthesized by the follicle cells in some bgcn chambers and in rare cases a columnar epithelium, which resembled morphologically that of wild-type stage-9 follicles, formed around the follicle's posterior end. The normal polarity of the follicular epithelium that is characteristic for mid-vitellogenic stages may, therefore, be established in the absence of morphologically differentiating germ-line cells. However, the tumorous germ-line cells do not constitute a homogeneous cell population since in about 30% of the analyzed follicles a cell cluster at or near the posterior pole can be identified by virtue of its high number of concanavalin A binding sites. This molecular marker reveals an anteroposterior polarity of the tumorous chambers. In follicles mutant for both bgcn and the polarity gene dicephalic the cluster of concanavalin A-stained germ-line cells shifts to more anterior positions in the follicle.
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  • 6
    ISSN: 1432-1939
    Keywords: Drosophila ; Microbial associations ; Resource partitioning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The distributions of five Drosophila species and four components of the microflora have been compared across a total of 48 traps baited with four different fruit and vegetable substrates in two domestic compost heaps in Canberra (Australia). Large and consistent differences are found, both among the Drosophila and among the microbial classes, in their distributions across traps baited with different substrates. Moreover the distribution of each Drosophila species shows a unique set of strong associations with the microbial distributions. Thus the distributions of both D. simulans and D. melanogaster are found to be strongly negatively correlated with the abundance of bacteria while D. simulans is also strongly positively correlated with the titre of fermenter yeasts. D. immigrans is strongly positively correlated both with bacteria and with non-fermenter yeasts. D. hydei is positively correlated with nonfermentery yeasts and D. busckii is negatively correlated with fermenter yeasts. Moulds are the only microbial class not consistently associated with the distribution of any of the Drosophila species. The correlations with the other microbial classes are sufficient to explain the majority of the abundance differences of the Drosophila species among the trap types. It is therefore proposed that the clear partitioning of the fruit resources by the Drosophila is due to their differing primary interactions with the microflora.
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  • 7
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    Journal of comparative physiology 166 (1989), S. 179-187 
    ISSN: 1432-1351
    Keywords: Blowfly ; Drosophila ; Photoreceptor ; Lanthanum ; trp mutant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of lanthanum on the light response of blowfly (Calliphora erythrocephala) photoreceptors was studied. The electrophysiological behaviour of the photoreceptors in the presence of La can be summarized as follows: 1. Upon long stimulation the photoreceptors responded with a ‘transient receptor potential’, i.e. the cells depolarized at the onset of the stimulus and then repolarized to (or below) the resting potential. This effect was dependent on stimulus intensity and occurred only at high intensities. During illumination membrane noise was reduced. 2. The light-induced changes in membrane potential were paralleled by changes in membrane resistance. 3. The time course of the receptor response was slowed down. 4. Light adaptation led to an increase in response latency. 5. The recovery of the receptor response after light adaptation was slowed down. 6. The sensitivity of the receptor cells measured by the response to short light stimuli was reduced. In summary, the electrophysiological behaviour of Calliphora photoreceptors in the presence of La was very similar to that of the photoreceptors of the trp (transient receptor potential) mutant of Drosophila melanogaster. This result suggests that La and trp mutation affect the same cellular processes in the photoreceptors.
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  • 8
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    Ecological research 4 (1989), S. 209-218 
    ISSN: 1440-1703
    Keywords: Annual life cycle ; Drosophila ; Fungus preference ; Nematode parasitism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Food preferences and nematode parasitism were studied in natural populations of mycophagousDrosophila in and near Sapporo, northern Japan. Species which preferred fresh mushrooms showed species-specific responses toPleurotus mushrooms:D. pirka bred only onPleurotus cornucopiae, D. trivitata onP. cornucopiae andP. ostreatus, D. trilineata on these twoPleurotus mushrooms and some other mushrooms, whileD. sexvittata bred on a wide variety of mushrooms but seldom onPleurotus mushrooms. Species which preferred decayed mushrooms (D. quadrivittata, D. histrioides, D. testacea and species of thequinaria species-group) showed host preferences different from those of the above species. The rate of parasitism by nematodes was generally higher in species which prefer decayed mushrooms than in species which prefer fresh mushrooms. Among species which prefer fresh mushrooms, onlyD. trilineata was parasitized frequently by nematodes. It was not clear what factors determine the rate of parasitism in these mycophagousDrosophila. D. pirka, D. trivittata andD. trilineata passed through three or four generations per year and entered reproductive diapause in early September in and near Sapporo.
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  • 9
    Electronic Resource
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    Springer
    Molecular and cellular biochemistry 90 (1989), S. 27-35 
    ISSN: 1573-4919
    Keywords: zerknullt gene ; homeobox protein ; Drosophila ; filter binding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Summary The region upstream from the zerknullt (zen) gene contains three sites that specifically bind the zen protein product of the gene. Evidence for these binding sites was obtained by the filter binding technique and the DNase footprinting technique. The filter binding technique was used to scan various segments of DNA for the presence of possible specific binding sites. Segments that were selectively retained by the filter binding technique invariably contained one or more specific binding sites according to the DNase footprinting technique. Two of the zen protein binding sites were spaced only 30 base pairs apart. These sites could be separated without any loss in their specific binding properties. It is concluded that these two sites function independently in the binding of zen protein.
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  • 10
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    Biochemical genetics 27 (1989), S. 507-520 
    ISSN: 1573-4927
    Keywords: Drosophila ; sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) ; glue proteins ; glycosylation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The patterns of protein fractions from total salivary glands and from glue plugs were compared in seven members of theDrosophila nasuta subgroup by the use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The glue protein patterns are member specific concerning the numbers and the electrophoretic mobilities of major and minor glue protein fractions. However, the major fractions of all subgroup members could be grouped into five SDS-PAGE domains according to the homologies of their electrophoretic mobilities, prominence of Coomassie blue staining, and PAS reaction. In all subgroup members, major fractions are involved in posttranslational modifications into larger protein molecules of the final glue. Quantitative estimations of the glue proteins inD. n. nasuta andD. n. albomicans reveal that they constitute between 55 and 60% of the total salivary gland proteins, whereas inD. melanogaster and inD. hydei the fraction is only 32 and 35%, respectively.
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  • 11
    Electronic Resource
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    Biochemical genetics 27 (1989), S. 507-520 
    ISSN: 1573-4927
    Keywords: Drosophila ; sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) ; glue proteins ; glycosylation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The patterns of protein fractions from total salivary glands and from glue plugs were compared in seven members of theDrosophila nasuta subgroup by the use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The glue protein patterns are member specific concerning the numbers and the electrophoretic mobilities of major and minor glue protein fractions. However, the major fractions of all subgroup members could be grouped into five SDS-PAGE domains according to the homologies of their electrophoretic mobilities, prominence of Coomassie blue staining, and PAS reaction. In all subgroup members, major fractions are involved in posttranslational modifications into larger protein molecules of the final glue. Quantitative estimations of the glue proteins inD. n. nasuta andD. n. albomicans reveal that they constitute between 55 and 60% of the total salivary gland proteins, whereas inD. melanogaster and inD. hydei the fraction is only 32 and 35%, respectively.
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  • 12
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    Springer
    Biochemical genetics 27 (1989), S. 263-277 
    ISSN: 1573-4927
    Keywords: Drosophila ; kinetic plate reader ; enzyme polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Techniques for performing numerous enzyme kinetic assays with minimum time and effort would be valuable to studies of the evolutionary genetics of metabolic control and the quantitative genetics of determinants of kinetic parameters. Microtiter plate readers have been used for a variety of repetitious analytical techniques, and instruments are available that can take repetitive readings with sufficient speed to perform kinetic assays. The ability of these instruments to assay rapidly the kinetic properties of small samples makes them potentially useful for a number of problems in population genetics. While the ability to handle large numbers of samples is very attractive, the small sample volumes and optical imprecision of microtiter plates result in some sacrifice in accuracy. This paper presents methods for performing kinetic assays on individual field-caughtDrosophila, quantifies the precision of these methods, and characterizes differences amongDrosophila melanogaster andD. simulans from samples caught in California and Pennsylvania. Comparisons between field-caught and laboratory rearedD. melanogaster show that most of the characters are very similar, with the exception of αGPDH, which has a threefold higher mean activity among field-caught flies. The phenotypic correlations are presented with a brief discussion of their relevance to assessing the evolution of metabolic control of these enzymes.
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  • 13
    ISSN: 1573-4927
    Keywords: Drosophila ; aldox-2 ; molybdoenzymes ; sulfite oxidase ; molybdenum ; tungsten
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Mutation at thealdox-2 locus inDrosophila melanogaster affects the specific activities of four molybdoenzymes differentially during development. Sulfite oxidase activity is normal during late larval and pupal stages but is reduced during early adult stages inaldox-2 organisms. There was complete concordance among the effects ofaldox-2 on sulfite oxidase, aldehyde oxidase, xanthine dehydrogenase, and pyridoxal oxidase, when 38 stocks were analyzed which were derived from single recombination events betweenc andpx, markers which flankaldox-2. Several different biochemical analyses indicate that the active molybdoenzymes present in thealdox-2 strain are normal with respect to size, shape,pH-activity profile,K m , and molecular weight. Significant differences were found between thealdox-2 strain and the OR control strain in their responses to dietary Na2MoO4 and Na2WO4. The mutant strain is much more resistant to the effects of dietary Na2WO4 and much more responsive to the administration of Na2MoO4 than the OR control strain when these effects are quantitated by measurements of molybdoenzyme specific activities. This evidence suggests that thealdox-2 + gene product has a molybdenum binding site which can also bind tungsten and that this site is altered in the mutant strain. The hypothesis presented explains the observed effects of thealdox-2 mutation and relates them to the other mutations reported in this gene-enzyme system.
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  • 14
    ISSN: 1573-3297
    Keywords: Drosophila ; circadian clock ; ultradian oscillations ; disconnected mutant ; visual system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Free-running locomotor activity and eclosion rhythms ofDrosophila melanogaster, mutant at thedisconnected (disco) locus, are substantially different from the wild-type phenotype. Initial periodogram analysis revealed little or no rhythmicity (Dushayet al., 1989). We have reanalyzed the locomotor activity data using high-resolution signal analysis (maximum-entropy spectral analysis, or MESA). These analyses, corroborated by autocorrelograms, uncovered significant residual circadian rhythmicity and strong ultradian rhythms in most of the animals tested. In this regard thedisco mutants are much like flies expressing mutant alleles of theperiod gene, as well as wild-type flies reared throughout life in constant darkness. We hypothesize that light normally triggers the coupling of multiple ultradian oscillators into a functional circadian clock and that this process is disrupted indisco flies as a result of the neural lesion.
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  • 15
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    Theoretical and applied genetics 77 (1989), S. 123-127 
    ISSN: 1432-2242
    Keywords: Inbreeding depression ; Drosophila ; Natural selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This experiment was designed to study the relationship between rate of inbreeding and observed inbreeding depression of larval viability, adult fecundity and cold shock mortality in Drosophila melanogaster. Rates of inbreeding used were full-sib mating and closed lines of N=4 and N=20. Eight generations of mating in the N=20 lines, three generations in the N=4 lines and one generation of full-sib mating were synchronised to simultaneously produce individuals with an expected level of inbreeding coefficient (F) of approximately 0.25. Inbreeding depression for the three traits was significant at F=0.25. N=20 lines showed significantly less inbreeding depression than full-sib mated lines for larval viability at approximately the same level of F. A similar trend was observed for fecundity. No effect of rate of inbreeding depression was found for cold shock mortality, but this trait was measured with less precision than the other two. Natural selection acting on loci influencing larval viability and fecundity during the process of inbreeding could explain these results. Selection is expected to be more effective with slow rates of inbreeding because there are more generations and greater opportunity for selection to act before F=0.25 is reached. Selection intensities seem to have been different in the three traits measured. Selection was most intense for larval viability, less intense for fecundity and, perhaps, negligible at loci influencing cold shock mortality.
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  • 16
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    Theoretical and applied genetics 77 (1989), S. 253-259 
    ISSN: 1432-2242
    Keywords: Heterosis ; Selection ; Drosophila ; Genotype x environment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Experiments were designed to examine whether heterosis would occur in crosses of Drosophila melanogaster populations adapted to 18 °C or 28 °C environments. Crosses were examined in parental environments, an intermediate environment (23 °C) and a mixed environment (alternating 18°/28°C). Parental populations did not show divergence for larval viability, cold shock or high temperature mortalities when tested in a common environment. However, the 28 °C population was less fecund than the 18 °C population, but had higher larval competitive ability and higher adult longevity. Heterosis for viability, cold shock mortality and high temperature mortality occurred in crosses between a population adapted to 18 °C and another adapted to 28 °C, but not in crosses between two populations adapted to the same temperature. The results suggest that, in the absence of drift, heterosis is expected in crosses between lines or populations with different histories of selection but not between lines with the same selection histories.
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  • 17
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    Cell & tissue research 258 (1989), S. 119-124 
    ISSN: 1432-0878
    Keywords: Development, ontogenetic ; Immunocytochemistry ; Monoclonal antibodies ; Mucosa ; Lymphoid organs ; Domestic fowl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The postnatal development of chicken mucosa-associated lymphoid tissues of the eyes, lungs, and intestines were investigated with monoclonal antibodies specific for either all leucocytes, B lymphocytes, mononuclear phagocytes, IgM, IgG, or IgA. Attention has been paid to the relation of lymphoid infiltrates with their surrounding mucosae, the segregation into B-cell and T-cell areas, development of germinal centers, and secretory immunoglobulins. Abudant secretory IgM and IgA was detected in the epithelium of the Harderian glands in the orbits, even though they lacked large leucocyte infiltrates with germinal centers. Lymphoid tissues in the mucosae of lungs and intestines developed separate B-cell and T-cell areas. The proventriculus, Meckel's diverticulum, and Peyer's patches generally contained germinal centers from 12 weeks of age on. Because chickens as young as 2 weeks old had germinal centers in bronchus-associated lymphoid tissue and cecal tonsils, these areas were probably highly stimulated by antigens. Isotype-specific monoclonal antibodies were used to detect IgM-, IgG-, and IgA-bearing follicular cells in the same germinal center.
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  • 18
    ISSN: 1432-0878
    Keywords: Insect AKH/RPCH ; Neurohormones ; Cam-HrTH-II ; Lom-AKH-I ; Immunocytochemistry ; Carausius morosus, Sarcophaga bullata (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A polyclonal antiserum was prepared against an N-terminal modified Cam-HrTH-II (Leu-Asn-Phe-...), one of the members of the large AKH/RPCH peptide family, first isolated from Carausius morosus. The localisation of this peptide was performed by means of immunocytochemical methods in the brain and corpora cardiaca-corpora allata complex of the stick insect, Carausius morosus and the grey fleshfly, Sarcophaga bullata. The distribution patterns of molecules reactive to the Cam-HrTH-II and the LomAKH-I antisera in both insect species were compared. In Carausius, both antisera reacted in the same cell bodies. In Sarcophaga, some neurons were stained by both, others only by one of the two antisera. By combining two different antisera, we demonstrated that there are no Lom-AKH-I-like molecules present in Carausius and that there must occur at least three different AKH-like molecules in the brain of Sarcophaga. One is similar to Cam-HrTH-II, the second to Lom-AKH-I and the third is an AKH/RPCH-like peptide, different from Lom-AKH-I and Cam-HrTH-II.
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  • 19
    ISSN: 1432-0878
    Keywords: Serotonin ; Immunocytochemistry ; Insect nervous system ; Protocerebrum ; Suboesophageal ganglion ; Manduca sexta (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Serotonin-immunoreactive neurons in the median protocerebrum and suboesophageal ganglion of the sphinx moth Manduca sexta were individually reconstructed. Serotonin immunoreactivity was detected in 19–20 bilaterally symmetrical pairs of interneurons in the midbrain and 10 pairs in the suboesophageal ganglion. These neurons were also immunoreactive with antisera against DOPA decarboxylase. All major neuropil regions except the protocerebral bridge are innervated by these neurons. In addition, efferent cells are serotonin-immunoreactive in the frontal ganglion (5 neurons) and the suboesophageal ganglion (2 pairs of neurons). The latter cells probably give rise to an extensive network of immunoreactive terminals on the surface of the suboesophageal ganglion and suboesophageal nerves. Most of the serotonin-immunoreactive neurons show a gradient in the intensity of immunoreactive staining, suggesting low levels of serotonin in cell bodies and dendritic arbors and highest concentrations in axonal terminals. Serotonin-immunoreactive cells often occur in pairs with similar morphological features. With one exception, all serotonin-immunoreactive neurons have bilateral projections with at least some arborizations in identical neuropil areas in both hemispheres. The morphology of several neurons suggests that they are part of neuronal feedback circuits. The similarity in the arborization patterns of serotonin-immunoreactive neurons raises the possibility that their outgrowing neurites experienced similar forces during embryonic development. The morphological similarities further suggest that serotonin-immunoreactive interneurons in the midbrain and suboesophageal ganglion share physiological characteristics.
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  • 20
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    Cell & tissue research 258 (1989), S. 101-109 
    ISSN: 1432-0878
    Keywords: Serotonin ; Immunocytochemistry ; Subesophageal ganglion ; Neurohemal organs ; Manduca sexta (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Serotonin-immunoreactivity is mapped in wholemounts and slices of the suboesophageal ganglion (SOG) of larval Manduca sexta by means of immunocytochemistry. An extensive meshwork of serotonin-immunoreactive nerve fibres on some peripheral nerves of the SOG has been demonstrated. This meshwork appears to belong to a serotonergic neurohemal system, probably supplied by two pairs of bilateral serotonin-immunoreactive neurons with big cell bodies on the dorsal side near the midline in the mandibular neuromere. Intracellular recording and staining revealed their physiology and morphology. These neurons produce long lasting (50 msec) action potentials, which suggest that they are neurosecretory cells. Two pairs of bilateral serotonin-immunoreactive interneurons similar to those of other insects are stained in the labial and maxillar neuromeres, but not in the mandibular neuromere. Their ventrolaterally located cell bodies project through a ventral commissure into the contralateral hemiganglion and then cross back again through a dorsal commissure. The axons project into the contralateral circumoesophageal connective.
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  • 21
    ISSN: 1432-0878
    Keywords: Na+, K+-ATPase ; Immunocytochemistry ; Kidney ; Salivary glands ; Transport ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An antibody to the 96 kD α-subunit of the Na+, K+ -ATPase from Bufo marinus has been used in immunostaining rat kidney and salivary glands. Intense staining was observed on basolateral membranes of distal tubules of the kidney and striated ducts of the three major salivary glands. Less intense staining was seen on the basolateral membranes of parotid acinar cells, but no staining was seen on the acinar cells of submandibular or sublingual glands. These sites of staining have been shown, by other methods, to posses substantial Na+, K+ -ATPase, indicating that the antibody recognizes antigenic determinants of the sodium pump highly conserved in the course of evolution. In addition, staining with this antibody was observed at the apical region of cells of the proximal straight tubule and of the papillary collecting duct in the kidney. Absorption studies suggest that the apical antigenic determinants are the same or closely related to each other but are distinct from basolateral antigenic determinants.
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  • 22
    ISSN: 1432-0878
    Keywords: Met-enkephalin-Arg6-Phe7 ; Met-enkephalin-Arg6-Gly7-Leu8 ; Immunocytochemistry ; Neuropeptides ; Co-existence of peptides ; Neurosecretory cells, insects ; Blowfly, Calliphora vomitoria (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neuronal pathways immunoreactive to antisera against the extended-enkephalins, Met-enkephalin-Arg6-Phe7 (Met-7) and Met-enkephalin-Arg6-Gly7-Leu8 (Met-8), have been identified in the brain of the blowfly Calliphora vomitoria. Co-localisation with other enkephalins in certain neurons suggests that a precursor similar to preproenkephalin A exists in insects and that differential enzymatic processing occurs as in vertebrates. Co-localisations of the extended-enkephalin-like peptides with other vertebrate-type peptides, including cholecystokinin and pancreatic polypeptide, also occur. The enkephalinergic pathways are specific, comprising a few groups of highly characteristic neurons and areas of neuropil. Of special interest is the finding that parts of the antennal chemosensory and the optic lobe visual systems contain Met-8 immunoreactive neurons. Within the median neurosecretory cell groups, some of the giant neurons show immunoreactivity to Met-8 and others to both Met-8 and Met-7. Fibres from these cells project to the corpus cardiacum and also to the suboesophageal ganglion, where arborisations occur in the tritocerebral neuropil. Co-localisation studies of these cells have shown that at certain terminals, one particular type of peptide is the dominant neuroregulator, whilst at other terminals, within the same cell, a different co-synthesised peptide predominates. Several groups of lateral neurosecretory cells show clearly defined enkephalinergic pathways, most of which have connections with the central body. The complex patterns of immunoreactivity seen in terminals in the different parts of the central body, suggest an important role for the enkephalin-like peptides in the integration of multimodal sensory inputs. The physiological functions of the extended-enkephalin-like peptides in the brain of Calliphora is still unknown, but the anatomical evidence suggests they may have a role similar to that in mammals, where they are thought to control aspects of feeding behaviour.
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  • 23
    ISSN: 1432-0878
    Keywords: Gut hormones ; Insulin ; Bombesin ; Immunocytochemistry ; Pancreatic polypeptide ; Cholecystokinin (CCK) ; Gastrin ; Schistocerca gregaria (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The endocrine cells of the midgut epithelium of the desert locust are found dispersed among the digestive cells and are similar to those of the vertebrate gut. According to their reactivity to silver impregnation techniques and the ultrastructural features of the secretory granules (shape, electron-density, size, and structure) 10 types of endocrine cell have been identified, of which seven are located in the main segment of the midgut or in the enteric caeca, and the other three seem to be present only in the ampullae through which the Malpighian tubules drain into the gut. The endocrine cells have a slender cytoplasmic process that reaches the gut lumen, a feature that supports the receptosecretory nature postulated for this cellular type in insects as well as vertebrates. Antisera directed against mammalian gastrin, CCK, insulin, pancreatic polypeptide and bombesin reacted with some of the endocrine cells. This is the first time that insulin- and bombesin-like immunoreactive cells have been described in the midgut of an insect.
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  • 24
    ISSN: 1432-0878
    Keywords: Somatotropes, growth hormone cells ; Immunocytochemistry ; Growth hormone (GH) ; Receptors, membrane ; Somatostatin (SRIF) ; Growth hormone-releasing hormone (GRH) ; Rat (Han: WIST)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The synthetic peptides somatostatin (SRIF) and growth hormone-releasing hormone (GRH) were coupled directly to colloidal gold of different particle sizes. Both conjugates were biologically active in displacing the corresponding radiolabeled hormones from high affinity binding sites in pituitary membranes. Release of growth hormone (GH) from cultured anterior pituitary cells was modulated by both conjugates alone or in combination. Ultrastructural studies were performed with cells incubated at 4° C (2 h) and 37° C (2 min-2 h) with one of the labeled peptides or their combination. Somatotropes were identified by immunostaining with anti-rGH followed by protein A-ferritin, thus obtaining a triple labeling. Both hormone conjugates were internalized in different vesicles in the beginning but accumulated during longer incubation times in the same compartment. The secretory vesicles and the nucleus were not labeled by any hormone conjugate. In contrast to SRIF-gold, the uptake of GRH-gold conjugate decreased with longer incubation times. This effect could be neutralized by simulatenous incubation of the somatotropes with both regulating hormones. Hence, whereas the binding and internalization of SRIF by somatotropes do not seem to be influenced by GRH, the corresponding processes for GRH are stimulated by the presence of SRIF.
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  • 25
    ISSN: 1432-0878
    Keywords: Gills ; Indoleamines ; Immunocytochemistry ; Autonomic innervation ; Salmo gairdneri R. ; Perca fluviatilis L. ; Micropterus dolomieui (Lacépède) ; Anguilla anguilla L. ; Ictalurus melas Rafinesque (Teleostei) ; Acipenser baeri L. (Chondrostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Antibodies against serotonin and 5-methoxytryptamine reveal indolaminergic neurons innervating the proximal part of the efferent arterial vasculature, the filament epithelia, the central venous sinus, and certain other serotonergic cells of the teleost gill filament. In the same area, acetylcholinesterase-positive and indoleaminergic neurons have already been described. We propose that these populations of neurons belong to a single neuronal type but express different agents. Our current results support this idea; in particular, they point to the presence of a single type of serotonin-containing nerve terminal, impinging on vascular smooth muscle. These results are in agreement with physiological data showing (i) the existence of non-cholinergic (atropine-resistant) vasoconstriction of the gill vasculature after nerve stimulation, and (ii) a potent vasoconstrictory action of infused serotonin. In addition, the above-mentioned serotonergic neurons have synaptic contacts with catecholaminergic nerve fibers, suggesting the existence of a modulatory relationship between the sympathetic and the cranial autonomic nerves supplying the teleost gill. Finally, these neurons show morphological relationships with a previously undescribed type of branchialserotonergic cell. The role of the parasympathetic nerve plexus of the teleost gill filament in the control of respiration and ionoregulation is discussed.
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  • 26
    ISSN: 1432-0878
    Keywords: Subcommissural organ ; Secretory activity, neural control ; Transplantation ; Long-spacing collagen ; Immunocytochemistry ; Molecular markers (neuronal, glial) ; Electron microscopy ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary There is increasing evidence that, in the rat, a serotonin-mediated neural input may have an inhibitory influence on the secretory activity of the subcommissural organ (SCO). In the present investigation the rat SCO was studied 7, 30 and 90 days after transplantation under the kidney capsule, an area devoid of local serotonin-containing nerves. The grafted tissue was examined by use of immunocytochemistry employing a series of primary antisera, lectin histochemistry and transmission electron microscopy. The grafted SCO survived transplantation and contained, in addition to secretory ependymal and hypendymal SCO-cells, also elements immunoreactive with antisera against glial fibrillary acidic protein or S-100 protein. In transplants, SCO-cells produced a material displaying the characteristic immunocytochemical and lectin-binding properties of SCO-cells observed under in-situ conditions. The ependymal cells lined 1–3 small cavities, which contained secretory material. A fully developed structural equivalent of Reissner's fiber was, however, never found. The immunocytochemical and ultrastructural study of the grafted SCO showed an absence of nerve fibers within the graft and suggested a state of enhanced secretory activity. A network of protruding basal lamina structures connected the secretory cells to the newly formed capillaries revascularizing the SCO. One week after transplantation, long-spacing collagen started to appear in expanded areas of such laminar networks and also in the perivascular space. It is suggested (i) that the formation of long-spacing forms of collagen is triggered by factors provided by the SCO-secretory cells, and (ii) that secretory material of the ependymal and hypendymal cells may reach the reticular extensions of the basal lamina. In contrast to the SCO in situ, the grafted SCO-cells showed a positive immunoreaction for neuron-specific enolase. They became surrounded by a S-100-immunoreactive glial sheath that separated them from other transplanted cell types and the adjacent kidney tissue of the host.
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  • 27
    ISSN: 1432-0878
    Keywords: Gonadotropin-releasing hormone-associated peptide (GAP) ; Luteinizing hormone-releasing hormone (LHRH) ; Brain mapping ; LHRH prohormone ; Immunocytochemistry ; Rat (Wistar-R)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The gonadotropin-releasing hormone-associated peptide (GAP) of the LHRH precursor and the decapeptide LHRH were localized in the rat brain by immunocytochemistry in 12 to 18-day-old animals, by use of thick Vibratome sections and nickel intensification of the diaminobenzidinereaction product. Our results indicate that the GAP portion of the LHRH precursor is present in the same population of neurons that contain LHRH in the rat brain. An important difference observed was that the GAP antiserum, in contrast to LHRH antisera, stained several perikarya in the medial basal hypothalamus. GAP-immunoreactive perikarya were observed in the following regions: the olfactory bulb and tubercle, diagonal band of Broca, medial septum, medial preoptic and suprachiasmatic areas, anterior and lateral hypothalamus, and several regions of the hippocampus. In addition to the preoptico-terminal and the septopreoptico-infundibular pathways, we also observed GAPimmunopositive processes in several major tracts and areas of the brain, including the amygdala, stria terminalis, stria medullaris thalami, fasciculus retroflexus, stria longitudinalis medialis, periventricular plexus, periaqueductal gray of the mesencephalon and extra-cerebral regions, such as the nervus terminalis and its associated ganglion. These results confirm the specificity of previous immunocytochemical results obtained with antisera to LHRH. The presence of GAP immunoreactivity in nerve terminals of the rat brain indicates that GAP or a GAP-like peptide is located in the proper site to serve as a hypophysiotropic substance and/or as a neurotransmitter or neuromodulator.
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  • 28
    ISSN: 1432-0878
    Keywords: Thyroid gland ; Cathepsin B ; Lysosomes ; Immunocytochemistry ; Diurnal rhythm ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Immunocytochemical localization of cathepsin B and thyroxine (T4) in follicular cells of the rat thyroid gland and plasma concentrations of thyroid stimulating hormone (TSH) were examined at six evenly spaced times over 24 h. By light- and electron microscopy, immunodeposits for cathepsin B were localized in cytoplasmic granules of various sizes, whereas those for T4 were detected mainly in larger granules of the cells and in the colloid lumen. The size and location of cytoplasmic granules showing immunoreactivity for cathepsin B and T4 in the cells varied over 24 h, corresponding to a change in plasma TSH concentrations. These immunopositive large granules appeared in the apical cytoplasm at 12.00 h, when the level of TSH was highest. At 20.00 h when the level of TSH was lowest, T4-positive granules almost disappeared, and cathepsin B-positive small granules were abundantly seen in the basal region. From 00.00 h to 08.00 h, these positive granules changed in the same manner as those seen from 12.00 h to 20.00 h, associated with an increase in plasma TSH levels. These results suggest that newly formed colloid droplets migrate from the apical to the basal regions. Cathepsin B may play a role not only in the degradation of thyroglobulin but in the maturation of thyroid hormones during the migration of the granules.
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  • 29
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    Cell & tissue research 256 (1989), S. 399-410 
    ISSN: 1432-0878
    Keywords: Dopamine ; Immunocytochemistry ; Brain, invertebrate ; Apis mellifera (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of dopamine-like immunoreactive neurons is described for the brain of the bee, Apis mellifera L., following the application of a pre-embedding technique on Vibratome sections. Immunoreactive somata are grouped into seven clusters, mainly situated in the protocerebrum. Immunoreactive interneurons have been detected in the different neuropilar compartments, except for the optic lobe neuropils. Strong immunoreactivity is found in the upper division of the central body, in parts of the stalk and in the α-lobe layers of the mushroom bodies. A dense network of many immunoreactive fibres surrounds the mushroom bodies and the central body. It forms a number of interhemispheric commissures/chiasmata, projecting partly into the contralateral mushroom body and central body. The lateral protocerebral neuropil contains some large wide-field-neurons. The antennal-lobe glomeruli receive fine projections of multiglomerular dopamine-like immunoreactive interneurons.
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  • 30
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    Cell & tissue research 257 (1989), S. 69-75 
    ISSN: 1432-0878
    Keywords: Inner ear ; Cytoskeletal proteins ; Immunocytochemistry ; Cell motility ; Actin ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Isolated outer hair cells of the guinea pig lacking a cuticular plate and its associated infracuticular network retain the ability to shorten longitudinally and become thinner. Membrane ghosts lacking cytoplasm retain the cylindrical shape of the hair-cell, and although they do not shorten, they retain the ability to constrict and become thinner. These data suggest that cytoplasmic components are associated with outer hair-cell longitudinal shortening and that the lateral wall is responsible for maintaing cell shape and for constriction. Actin, a protein associated with the cytoskeleton and cell motility, is thought to be involved in outer hair-cell motility. To study its role, actin was localized in isolated outer hair cells by use of phalloidin labeled with fluorescein and antibodies against actin coupled to colloidal gold. In permeabilized guinea-pig hair cells stained with phalloidin, actin filaments are found along the lateral wall. In frozen-fixed hair cells actin filaments are distributed uniformly throughout the cytoplasm. Electron-microscopic studies show that antibodies label actin throughout the outer hair-cell body. Thus cytoplasmic actin filaments may provide the structural basis for the contraction-like events.
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  • 31
    ISSN: 1432-0878
    Keywords: Antigen localization ; FMRFamide-like immunoreactivity ; Immunocytochemistry ; Invertebrate ganglia ; Small cardioactive peptide-like immunoreactivity ; Hirudo medicinalis (Annelida)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distributions of small cardioactive peptide (SCP)- and FMRFamide-like immunoreactivities in the central nervous system of the medicinal leech Hirudo medicinalis were studied. A subset of neurons in the segmental ganglia and brains was immunoreactive to an antibody directed against SCPB. Immunoreactive cell bodies were regionally distributed throughout the nerve cord, and occurred both as bilaterally paired and unpaired neurons. The majority of the unpaired cells displayed a tendency to alternate from side to side in adjacent ganglia. A small number of neurons were immunoreactive only in a minority of nerve cords investigated. Intracellular injections of Lucifer yellow dye and subsequent processing for immunocytochemistry revealed SCP-like immunoreactivity in heart modulatory neurons but not in heart motor neurons. FMRFamide-like immunoreactivity was also detected in cell bodies throughout the central nervous system. A subset of neurons contained both SCP- and FMRFamide-like immunoreactivities; others stained for only one or the other antigen. These data suggest that an antigen distinct from FMRFamide is responsible for at least part of the SCP-like immunoreactivity. This antigen likely bears some homology to the carboxyl terminal of SCPA and SCPB.
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  • 32
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    Cell & tissue research 256 (1989), S. 559-565 
    ISSN: 1432-0878
    Keywords: Retrograde tracing ; Immunocytochemistry ; Vascular innervation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The origin of nerve fibers to the superficial temporal artery of the rat was studied by retrograde tracing with the fluorescent dye True Blue (TB). Application of TB to the rat superficial temporal artery labeled perikarya in the superior cervical ganglion, the otic ganglion, the sphenopalatine ganglion, the jugular-nodose ganglionic complex, and the trigeminal ganglion. The labeled perikarya were located in ipsilateral ganglia; a few neuronal somata were, in addition, seen in contralateral ganglia. Judging from the number of labeled nerve cell bodies the majority of fibers contributing to the perivascular innervation originate from the superior cervical, sphenopalatine and trigeminal ganglia. A moderate labeling was seen in the otic ganglion, whereas only few perikarya were labeled in the jugular-nodose ganglionic complex. Furthermore, TB-labeled perikarya were examined for the presence of neuropeptides. In the superior cervical ganglion, all TB-labeled nerve cell bodies contained neuropeptide Y. In the sphenopalatine and otic ganglia, the majority of the labeled perikarya were endowed with vasoactive intestinal polypeptide. In the trigeminal ganglion, the majority of the TB-labeled nerve cell bodies displayed calcitonin gene-related peptide, while a small population of the TB-labeled neuronal elements contained, in addition, substance P. In conclusion, these findings indicate that the majority of peptide-containing nerve fibers to the superficial temporal artery originate in ipsilateral cranial ganglia; a few fibers, however, may originate in contralateral ganglia.
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  • 33
    ISSN: 1432-0878
    Keywords: Insulin-related peptide ; Immunocytochemistry ; Immunochemical characterization ; Pancreas ; Ambystoma mexicanum (Urodela)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pancreas of the axolotl, Ambystoma mexicanum, was investigated by immunocytochemical methods for the presence of immunoreactivity to a number of antisera raised against mammalian insulins. All anti-insulin antisera tested revealed substantial amounts of reaction products confined solely to the aldehyde-fuchsinophilic B cells of the endocrine pancreas. The reactive cell population was detected by use of one polyclonal antiserum against bovine insulin and eight different monoclonal antibodies against insulins from various mammalian species. Six of these antibody clones have known specificity to sub-regions of the insulin molecule. Additionally, fractions of an ethanol-HCl extract of pancreatic tissue from Ambystoma was studied in both conventional dot-blot tests by means of the same panel of antibodies and a two-site sandwich time-resolved immunofluorometric assay for human insulin involving two of the monoclonal antibodies. These experiments support the immunocytochemical observations by demonstrating the existence of an insulin-related peptide with a great deal of structural resemblance to mammalian insulins and displaying antigenic determinants in common at least with the amino acid residues A8–10 and B26–30. In conclusion, we interpret the findings as indicating that the immunocytochemically revealed tissue bound antigen in the Ambystoma pancreatic B-cells may be a peptide related to human insulin.
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  • 34
    ISSN: 1432-0878
    Keywords: Immunocytochemistry ; Prolactin cells ; Gonadotropic cells ; ACTH cells ; Folliculo-stellate cells ; Rana pipiens (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The colloidal gold immunocytochemical technique was used to determine the ultrastructural features of the glandular cells in the pituitaries of male frogs, Rana pipiens, both in vivo and after superfusion in vitro. Specific reactions to antisera against bullfrog gonadotropins, human prolactin, and synthetic 1–39 corticotropin allowed identification of the 3 corresponding types of glandular cells. No immunoreaction was obtained with antisera against human or ovine-growth hormone, human β-thyrotropin hormone, and bovine S-100 protein. General morphological features of these immunocytochemically identified glandular cells were similar to those of equivalent cells previously described in other amphibian species. Non-glandular folliculo-stellate cells were distinctive. In freshly removed pituitaries, these folliculo-stellate cells contained lysosome-like structures, but did not show phagocytic vacuoles in the cytoplasm; they contained many mitochondria, and the Golgi complex and endoplasmic reticulum were relatively undeveloped. After 4 or 18 h of superfusion, some immunoreactive gonadotropic, prolactin, and corticotropic cells showed degeneration and destruction. In the same gland, folliculo-stellate cells retained a viable appearance, but showed phagocytic vacuoles containing secretory granule-like structures which were immunoreactive to gonadotropic, prolactin, and corticotropic antibodies. Some folliculo-stellate cells showed phagocytic vacuoles containing complete glandular cells. These results suggest that superfusion causes a destruction of some of the glandular cells, and that folliculo-stellate cells act as phagocytes when cellular debris or moribund cells are present in the intercellular space in the pituitary parenchyma.
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  • 35
    ISSN: 1432-0878
    Keywords: S-100 protein ; Immunocytochemistry ; Saccus vasculosus ; Pituitary gland, pars nervosa ; Mustelus manazo, Scyliorhinus torazame(Elasmobranchii)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary S-100 protein-immunoreactive cells were demonstrated by immunocytochemical procedures in the hypophysis and saccus vasculosus of two species of elasmobranchs (Mustelus manazo and Scyliorhinus torazame). In the saccus vasculosus of M. manazo, immunoreactivity was detectable exclusively in the fibrous portions interposed between the epithelial layer and the blood vessels. In the neurohypophysis, tanycytes and astrocytes of the median eminence were immunostained, but only a few labeled cells were found in the neurointermediate lobe. In S. torazame, the neurohypophysis displayed a similar distribution of immunoreactivity, but there were no labeled cells in the saccus vasculosus. In both species, none of the glandular cells of the hypophysis displayed immunoreactivity. Electron-microscopic examination showed that the immunostained cells in the saccus vasculosus correspond to astrocytes.
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  • 36
    ISSN: 1432-0878
    Keywords: Development ; Intrapulmonary chemoreceptor ; Immunocytochemistry ; Morphometry ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution, frequency and size of neuroepithelial bodies (NEB) were studied in lungs of rabbits during different stages of development (27-day fetus, newborn, 6, 11, 21, 28 and 56 days postnatally). NEB were visualized by immunostaining with monoclonal antibody against serotonin. Detailed quantitiation of NEB was performed by use of camera lucida drawings of immunostained serial sections from the same anatomical region, i.e. the lower lobe of the left lung. The total number of NEB was counted and expressed per epithelial length of airway, surface area and volume. The size of NEB defined as surface area as well as the position of NEB in relation to the airway bifurcations was assessed in airways of different sizes. The overall number and size of NEB were found to increase during the immediate perinatal period followed by a sharp decline at 56 days of age. The number of NEB peaked at 6 days postnatally (mean 175.5 NEB/mm3 of airway epithelium) and declined significantly (3.0 NEB/mm3) at 56 days of postnatal age. The size of NEB reached its maximum at 11 days (mean surface area 659.54 μm2, with the largest NEB measuring 1839.98 μm2). By 56 days of age, NEB became significantly smaller (mean surface area 177.29 μm2) consisting of small clusters of cells situated deep within the airway epithelium. At all ages, about half of all NEB (mean 47.6%) were localized within the small peripheral airways with up to 63.9% located at airway bifurcations. These findings indicate that the “functional activity” of NEB may be confined predominantly to the perinatal period. The postulated functions of NEB include those of intrapulmonary hypoxia-sensitive chemoreceptors and/or endocrine-paracrine activity in the lung. Such function(s) may be important during adaptation to extrauterine life as well as for growth and development of the lung.
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  • 37
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    Cell & tissue research 256 (1989), S. 45-51 
    ISSN: 1432-0878
    Keywords: Testis ; Leydig cells ; Basement membrane ; Laminin ; Collagen ; Immunocytochemistry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Rat testes were examined by conventional and immunolabeling transmission electron microscopy. Ultrastructurally identifiable continuous basement membranes were found around seminiferous tubules and the interstitial capillaries. Patches of basement membrane were, additionally, found on free surfaces of Leydig cells, between two Leydig cells, and in macrophage-Leydig cell contact sites. The ultrastructural findings were confirmed by immunocytochemical localization of laminin and collagen type IV in the same areas. A close association between the capillary basement membranes and the surfaces of perivascular Leydig cells was also observed. The possible basement membrane-mediated interactions of Leydig cells with other testicular structures, together with the novel bioactive products and regulators of Leydig cells, support the role of these cells as exceptionally complex regulatory centers of testicular functions.
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  • 38
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    Cell & tissue research 256 (1989), S. 153-158 
    ISSN: 1432-0878
    Keywords: Acetylcholine ; Acetylcholinesterase ; Cholin-acetyltransferase ; Immunocytochemistry ; Visual system ; Calliphora erythrocephala (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of putative cholinergic neurons in the lamina of the blowfly Calliphora erythrocephala was studied by immunocytochemical and histochemical methods. Three different antibodies directed against the AChsynthesizing enzyme, choline acetyltransferase (ChAT), revealed a cholinergic population of fibres running parallel to the laminar cartridges, which have branch-like structures at the distal lamina border. Cell bodies in the chiasma next to the lamina border were also labelled by the anti-ChAT antibodies. Monopolar cell bodies in the nuclear layer were faintly labelled. The distribution of the acetylcholine hydrolyzing enzyme, acetylcholine esterase (AChE), was revealed by histochemical staining and was similar to the ChAT immunocytochemistry. The arrangement of ChAT positive fibres in transverse and longitudinal sections and the distribution of AChE stained fibres indicate that the amacrine cells of the lamina are cholinergic cells.
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  • 39
    ISSN: 1432-0878
    Keywords: Pancreas, endocrine ; Cysteamine ; Somatostatin ; Insulin secretion ; Glucose ; Immunocytochemistry ; Mouse (NMRI)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To evaluate the previously reported depletion of pancreatic somatostatin by cysteamine (β-mercaptoethylamine), mice were injected subcutaneously with the drug at 300 mg/kg. Immunocytochemical analysis performed on sections from tissue taken at 4 h after the injection revealed an elimination of somatostatin-14-like immunoreactivity without alterations in the somatostatin-28(1 – 12)-like immunoreactivity. In sections from tissues taken at 24 h after injection, no differences between cysteamine-injected animals and controls were observed. Immunochemical analysis of somatostatin-14-like immunoreactivity in pancreatic extracts showed a significant reduction of the concentration (P〈 0.001). In contrast, no change in the insulin concentration was observed. Functionally, cysteamine lowered the plasma glucose levels at l h after injection; this effect persisted for 6 h. Plasma insulin levels were likewise reduced transiently by cysteamine. Concomitant administration of somatostatin did not influence these effects of cysteamine. The plasma glucose-lowering effect of cysteamine was seen also in alloxan-diabetic mice. We conclude that cysteamine alters the immunoreactive characteristics of pancreatic somatostatin without affecting the immunoreactivity of insulin, and that cysteamine transiently reduces plasma glucose and insulin levels
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  • 40
    ISSN: 1432-0878
    Keywords: FMRFamide ; Cholecystokinin ; Immunocytochemistry ; Insect visual system ; Neural development ; Calliphora erythrocephala (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The adult optic lobes of the blowfly Calliphora erythrocephala were found to be innervated by more than 2000 neurons immunoreactive to antisera raised against the neuropeptides FMRFamide, its fragment RFamide, and gastrin/cholecystokinin (CCK). All of the CCK-like immunoreactive (CCK-IR) neurons also reacted with antisera to RFamide, FMRFamide and pancreatic polypeptide. A few RFamide/FMRFamide-like immunoreactive (RF-IR) neurons did not react with CCK antisera; they reacted instead with antisera to Leu-enkephalin and Met-enkephalin-Arg6-Phe7. The RF-IR neurons are, thus, heterogeneous with respect to their contents of immunoreactive peptides. Two of the RF-IR neuron types innervating the adult optic lobes could be traced in their entirety only after following their postembryonic development, because of the complexity of the trajectories of the immunoreactive neuronal process in the adult insect. The majority of the cell bodies of the RF-IR and CCK-IR neurons lie within the optic lobes and are derived from imaginal neuroblasts of the inner and outer optic anlagen. Six of the peptidergic neurons are, however, metamorphosing larval neurons with their cell bodies in the central part of the protocerebrum. The full extent of immunoreactivitiy is not attained in some of the neurons until the late pupal or early adult stage. The larval optic center was also found to be innervated by neurons immuno-reactive with both RFamide and CCK antisera. The cell bodies of these RF-IR/CCK-IR neurons are located near the developing lamina (one on each side). In the 24 h pupa, the cell bodies of these neurons are still immunoreactive, but thereafter they cannot be immunolabeled apparently due to cell death or a change in transmitter phenotype.
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  • 41
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    Cell & tissue research 255 (1989), S. 645-650 
    ISSN: 1432-0878
    Keywords: Pituitary, pars distalis ; Differentiation ; Organ culture ; Immunocytochemistry ; Rat (Sprague-Dawley, CFY)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An immunohistochemical study was performed to determine the capacity of early fetal pituitaries to differentiate into specific hormone-synthesizing tissue in the absence of any influence from the central nervous system. Rathke's pouches from rats were removed from their juxtadiencephalic position on day 11 and 12 of gestation and maintained for 2–7 days in a chemically defined culture medium (M 199) without antibiotics and serum supplementation. The immunocytochemical observations provided evidence for the differentiation of ACTH-, TSH-gb-, LH-gb-, FSH-gb-, GH- and PRL-synthesizing cells in the isolated organ cultured from 11 to 12-day-old pituitary primordia. The appearance of specific hormone-synthesizing cells in vitro displayed a delay of 1.5–2 days compared to the day of appearance in vivo, however, the sequential order of developmental events occurred as observed in vivo. The present results suggest that endocrine or neuroendocrine signals are not required for the expression of specific secretory functions of fetal pituitaries, at least at an age of 11–12 days.
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  • 42
    ISSN: 1432-0878
    Keywords: Hypophyseal pars tuberalis ; (TSH), Thyrotropin ; Immunocytochemistry ; Photoperiod ; Phodopus sungorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Specific secretory cells in the hypophyseal pars tuberalis of Djungarian hamsters maintained under different photoperiods were investigated immunocytochemically by means of the colloidal gold technique using antibodies against rat thyrotropin (TSH). Secretory cells of animals kept under long photoperiods (LD16:8) showed positive staining of secretory granules (diameters 90–130 nm), whereas other intracellular structures were free of immunoreactivity. In animals kept under short photoperiods (LD8:16) secretory cells displayed increased numbers of secretory granules, but these organelles were devoid of immunoreactivity. In contrast, immunoreactivity of thyrotropes in the pars distalis did not differ between the two groups of animals investigated. The present results confirm earlier light-microscopical studies that in the pars tuberalis specific secretory cells show TSH-like immunoreactivity; however, they differ in their reactivity pattern from classical thyrotropes in the pars distalis.
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  • 43
    ISSN: 1432-0878
    Keywords: Neuropeptides ; Monoclonal antibodies ; Immunocytochemistry ; Endocrine system ; Nervous system ; Leptinotarsa decemlineata (Say)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Monoclonal antibodies were developed against peptidergic neurons in the nervous and endocrine tissues of the Colorado potato beetle by the immunization of mice with unpurified homogenates of these tissues. Methods were optimized to enhance chances for successful antibody production and selection, such as the pretreatment of the beetles, preparation of the immunogen, and screening hybridomas. Although only sub-microgram quantities of peptide antigen were used, many hybridomas generated antibodies recognizing peptidergic neurons in immunocytochemical procedures. A panel of 13 monoclonal antibodies anti-Colorado potato beetle (MACs) were harvested. All MACs stained different populations of peptidergic neurons, some of which had not been revealed by previously applied identification methods. Apart from the intrinsic glandular cells in the corpora cardiaca, immunoreactive neurosecretory neurons were revealed in medial and lateral groups in the protocerebrum and in the suboesophageal ganglion. These have axons terminating in the corpora cardiaca, and the neurosecretory granules can be revealed with the immunogold method. It is suggested that the immunoreactive substances represent neuropeptides or precursors of different kinds. Interneurons in other locations in the central and visceral nervous system have immunoreactive axonal projections that do not leave the ganglia. The set of MACs obtained is useful for neuroanatomical studies, for characterizing the secretory products, and for a further delineation of peptidergic communication channels in the insect body.
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  • 44
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    Cell & tissue research 255 (1989), S. 215-224 
    ISSN: 1432-0878
    Keywords: Transglutaminase ; Immunocytochemistry ; Induction ; Tissue compartments ; Tissue integrity ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Tissue transglutaminase is an intracellular enzyme without established physiological function. Biochemically it can be detected in all organs, but no systematic in situ localization has been carried out so far. Here we report the immunohistochemical localization of transglutaminase in human tissues using an affinity purified, monospecific anti-human transglutaminase antibody. It is shown that the widespread organ distribution of the enzyme is the consequence of its occurrence in ubiquitous cell types such as endothelium and smooth muscle cells. Some organ-specific cell types express the enzyme constitutively (mesangial cells, renomedullary interstitial cells, thymic subcapsular epithelium, colonic pericryptal fibroblasts), while in others it seems to be induced either by external stimuli (epithelium of the female breast) or as part of their differentiation/maturation program (developing nephrons, enterocytes of the small intestine). The presence of tissue transglutaminase can be demonstrated in derivatives of all germ layers and in the trophoblast. The functional implications of these findings are presently unknown; however, based on its distribution the role of this enzyme in compartmentation and preservation of tissue integrity against stress may be suggested.
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  • 45
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Neural lobe ; Intermediate lobe ; Intraventricular graft ; Immunocytochemistry ; Electron microscopy ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neurointermediate lobes from adult or 10-dayold rats were implanted by a stereotaxic procedure into the third ventricle of adult male rats, in an area close to the paraventricular nucleus. They were examined, using immunocytochemical and ultrastructural techniques, at times ranging from 1 week to 8 months. All grafts were recovered in a healthy condition although some rejection of the tissue was detected at the 1and 2-week stages. In the neural lobe, clusters of pituicytes were scattered among the loose network of capillaries, most of which had a fenestrated endothelium. The intermediate lobe remained organized in compact avascular lobules. Axons similar to those projecting into the neurointermediate lobe in situ, but also axons of other types (e.g., somatostatinergic, enkephalinergic) penetrated the grafts. Synapses with melanotrophic cells in the intermediate lobe and neurohaemal contacts in the neural lobe were frequent from 2 1/2 months after transplantation. Immunocytochemical and ultrastructural characteristics indicated intense secretory stimulation of the melanotrophic cells in the early stages. All cells enclosed in a same glandular lobule reacted in a similar manner. In later stages, when re-innervation occurred, the cells recovered their initial characteristics. The overall effect of the re-innervation of the intermediate lobe grafted in this location is inhibitory, as in the lobe in situ.
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  • 46
    ISSN: 1432-0878
    Keywords: Spinal cord ; Dorsal root ganglia ; Skin ; Immunocytochemistry ; Neuropeptides ; Mutilated foot rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The mutilated foot rat is a mutant with autosomal recessive sensory neuropathy and frequent mutilation of the hindlimbs. Decreased numbers of dorsal root ganglion cells and diminished sensitivity to painful stimuli are characteristics of these animals. By use of immunocytochemistry, changes in the distributions of peptides involved in sensory and/or autonomic regulation, i.e. calcitonin generelated peptide (CGRP), tachykinins, enkephalin and neuropeptide Y in spinal cord, dorsal root ganglia and skin of these animals, were studied. In comparison with normal litter-mate controls, the dorsal horn of mutilated foot rats contained substantially fewer CGRP and tachykinin-immunoreactive fibres but more fibres immunoreactive for enkephalin. Many enkephalin-immunoreactive cell bodies were also found in the dorsal horn of the mutants, by contrast none were visible in control animals. Neuropeptide Y immunoreactivity was, however, unchanged in the spinal cord of the mutants. In the dorsal root ganglia of the mutants, the number of CGRPor tachykinin-immunoreactive cells and their proportion to total neuronal numbers were significantly less in comparison with normal controls. The diameter range of CGRP- and tachykinin-immunoreactive cells shifted from small (15–25 μm) to medium size (25–45 μm) as revealed by frequency distribution histograms. The skin from the affected foreand hindlimbs of the mutant rats, in keeping with fewer CGRP- and tachykinin-immunoreactive cells in the dorsal root ganglia, contained substantially less fibres immunoreactive for CGRP and tachykinins; a difference that was not seen in skin of unaffected areas (whiskers and snout). By contrast, neuropeptide Y-immunoreactive fibres showed a normal distribution around blood vessels and sweat glands of mutilated foot rats. The data suggest that diminished pain perception in the mutilated foot rat is related to loss of peptide-containing sensory neurones. Furthermore, the intraspinal increase of enkephalinergic neurones in the dorsal horn, concomitant with the decreased number of primary sensory neurones, may also play a contributory rôle in reducing pain thresholds.
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  • 47
    ISSN: 1432-0878
    Keywords: Cell proliferation ; Immunocytochemistry ; Lung ; Bronchioles ; Alveoli, lung ; Proliferating cell nuclear antigen ; Type II pneumocyte ; Clara cell ; Mouse (various strains)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Proliferating cell nuclear antigen is expressed in cells from late G1 through the S-phase of the cell cycle. Therefore, antibodies directed against this molecule should provide a probe for labeling immunocytochemically the nuclei of proliferating cells. Herein we demonstrate the feasibility and reliability of this technique by quantifying immunostained pulmonary nuclei. We applied polyclonal and monoclonal antisera to alveolar and bronchiolar pulmonary epithelial cells in various proliferative states in tissue-sections and in vitro. A/J mice had a slightly higher labeling index than C57BL/6J mice, and proliferation in both strains increased dramatically after butylated hydroxytoluene treatment produced compensatory hyperplasia of Type-II pneumocytes. Immunostaining in fetal and neonatal lung samples from mice was higher than in adults. Spontaneous lung adenomas had a higher labeling index than the surrounding normal lung tissue. In addition, new data contained herein demonstrate a strain difference in proliferation of bronchiolar epithelial cells, and quantify the extent to which BHT-induced lung damage increases these proliferative rates. This mammalian nuclear antigen did not cross-react with antiserum to a functionally related bacterial protein, the beta subunit of E. coli DNA polymerase-III holoenzyme.
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  • 48
    ISSN: 1432-0878
    Keywords: Pars distalis ; Prolactin/thyrotropic cells ; TRH ; Immunocytochemistry ; Morphometry ; Rana perezi (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of synthetic thyrotropin-releasing hormone on pituitary prolactin and thyrotropic cells were investigated in adult male Rana perezi (formerly Rana ridibunda) frogs. Animals were given daily injections of synthetic thyrotropin-releasing hormone into the dorsal lymph sac. Prolactin and thyrotropic cells were identified by the colloidal-gold method, using anti-human prolactin and anti-human-β-thyrotropin hormone as primary antisera. The stereological parameters of the rough endoplasmic reticulum, Golgi complex, and secretory granules of prolactin and thyrotropic cells were evaluated by ultrastructural morphometry (point-counting method). Thyrotropin-releasing hormone caused cytological changes in both cell-types which were consistent with increased synthesis and release of both prolactin and thryrotropin. These changes were still significant after 48 h treatment in the case of thyrotropic cells, while in prolactin cells the thyrotropin-releasing hormone increased the number of secretory granules. After 6 days, the cells resembled essentially those used as controls. These results indicate that thyrotropin-releasing hormone stimulates the synthesis and release of prolactin and thyrotropin, and that the response of each cell type to this hypothalamic stimulus follows a different time-course.
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  • 49
    ISSN: 1432-0878
    Keywords: Peptides ; Small intensely fluorescent (SIF) cell ; Neuropeptide coexistence ; Inferior mesenteric ganglion ; Immunocytochemistry ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Coexistence of peptides in the small intensely fluorescent cells was demonstrated by immunocytochemistry for met-enkephalin-Arg-Gly-Leu, vasoactive intestinal polypeptide, somatostatin, neuropeptide Y and dynorphin. In the extreme example, a single cell was immunoreactive to all 5 peptides examined. Four peptides coexisted in 8% and three peptides in 13% of SIF cells. In 10% of SIF cells no peptide immunoreactivity could be detected. The most prevalent peptide was met-enkephalin (in 46% of cells), then vasoactive intestinal polypeptide (45%), somatostatin (39%), neuropeptide Y (31%) and dynorphin (24%). Met-enkephalin and vasoactive intestinal polypeptide coexisted most commonly (25%).
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  • 50
    ISSN: 1432-0878
    Keywords: Endocrine heart ; Estradiol ; Autoradiography ; Immunocytochemistry ; Co-localization ; CDD/ANP gene regulation ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Atrial myoendocrine cells of rat were investigated regarding estradiol uptake. It was found that, in addition to their specific endocrine function of producing cardiac polypeptides of the cardiodilatin/atrial natriuretic peptide (CDD/ANP) family, these cells also specifically accumulate radiolabeled estradiol. This co-localization supports the view that steroid hormones play an important role in the regulation of the CDD/ANP gene.
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  • 51
    ISSN: 1432-0878
    Keywords: Prolactin cells ; Growth hormone cells ; In situ hybridization ; Immunocytochemistry ; Cytogenesis ; Rat (Wistar-Imamichi)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cytogenesis of growth hormone and prolactin cells in the rat pituitary gland was studied using in situ cDNA-mRNA hybridization and immunocytochemistry. Frozen or Paraplast sections of fetal and neonatal pituitaries were hybridized with 3H-cDNAs for rat prolactin or growth hormone, and were then processed for autoradiography. A number of growth hormone mRNA-positive cells were encountered throughout the anterior lobe on day 19 of gestation. Individual variaction in growth hormone gene expression was observed between fetuses at day 19 of gestation (6 out of 8 fetuses examined were positive for growth hormone mRNA). In contrast, growth hormone mRNA was detected in the all fetuses examined on day 20 or later. The autoradiographic signal (number of reduced silver grains) appeared to increase with later stages of development. Fetal growth hormone mRNA-positive cells were evenly scattered throughout the anterior lobe. Most of them were isolated, however, small clusters of several growth hormone cells were infrequently observed. Prolactin mRNApositive cells were found first on the 22nd day (the last day of gestation) in 3 of 6 fetuses examined, but were rarely observed on earlier gestational days. By postnatal day 8, prolactin mRNA-positive cells were numerous and the grain density over prolactin cells increased. Both growth hormone and prolactin cells were found as early as 18 days of gestation using immunocytochemistry, although the number of positive cells was very small at this stage. Immunoreactive growth hormone cells increased sharply in number during the next 24 h, while the number of prolactin cells remained scarce until birth. The results suggest that many growth hormone cells are still in an immature state at 20∶00 of day 18 and that many begin to synthesize growth hormone mRNA during next 14 h. On the other hand, no substantial prolactin gene expression appears to take place until after birth.
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  • 52
    ISSN: 1432-0878
    Keywords: Nucleus intercollicularis ; α2-Adrenergic receptors ; Estrogen receptors ; Quantitative autoradiography ; Immunocytochemistry ; Japanese quail, Coturnix coturnix japonica (Aves, Phasianiformes)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The nucleus intercollicularis is an important site in the control of vocalization in birds. In oscines, a subregion of the nucleus intercollicularis called the dorso-medial intercollicular nucleus appears to play a key role in this process because it receives the majority of the projections from the nucleus robustus archistriatalis and sends most of the projections to the motor nucleus of the hypoglossal nerve. In this paper, we present neurochemical studies of the nucleus intercollicularis in the Japanese quail which suggest the presence of heterogeneity within this structure. One rostral band contains high densities of cholinergic muscarinic receptors identified by quantitative autoradiography using tritiated N-methylscopolamine as the ligand. A caudal dorso-medial region is specifically labeled by estrogen receptors identified using immunocytochemistry and by α2-adrenergic receptors which were quantified by autoradiography using tritiated para-amino-clonidine. This latter sub-region is possibly equivalent to the dorso-medial intercollicular nucleus of oscines. Additional track-tracing studies should be performed to confirm this homology. The coexistence of estrogen and α2-adrenergic receptors within the same structure suggests important functional connections between steroid action and catecholaminergic systems in the brain.
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  • 53
    ISSN: 1432-0878
    Keywords: Thyrotropin-releasing hormone (TRH) ; Development, ontogenetic ; Anterior hypothalamus ; Immunocytochemistry ; Domestic mallard
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Developmental changes of thyrotropin-releasing hormone (TRH)-immunoreactive structures in the brain of mallard embryos were studied by means of immunocytochemistry (PAP technique). The primary antibody was generated against synthetic TRH. Immunoreactive neurons were first detected in the hypothalamus of 14-day-old embryos. By day 20, increasing numbers of immunoreactive perikarya were observed in the paraventricular nucleus, anterior preoptic region and supraoptic region. Immunoreactive fiber projections were seen in the median eminence as early as embryonic day 20; they occurred also in some extrahypothalamic regions (lateral septum, accumbens nucleus). The number and staining intensity of the cell bodies increased up to hatching, and continued to increase during the first week after hatching.
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  • 54
    ISSN: 1432-0878
    Keywords: Olfactory-marker protein (OMP) ; Olfactory epithelium ; Immunocytochemistry ; Protein G-gold ; Freeze-substitution ; Lowicryl K11M embedding ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In this study electron-microscopic immunocytochemistry was used to localize olfactory marker protein in olfactory epithelia. Rat olfactory-epithelial samples were rapidly frozen, freeze-substituted with acetone, embedded at low temperatures with Lowicryl K11M and labelled on the sections with polyclonal antibodies raised against olfactory marker protein and with protein G conjugated to colloidal gold. Apart from the aforementioned use of acetone, substitution was carried out in the complete absence of chemical fixation, i.e., neither aldehydes nor OsO4 were used. This procedure resulted in localization concurrent with a good ultrastructural preservation. Olfactory-marker protein was present throughout the cytoplasmic compartments of dendrites and dendritic endings of olfactory-receptor cells, but it was not found in organelles such as mitochondria. Olfactory-marker protein was found only in dendriticendings of olfactory-receptor cells mature enough to have given rise to cilia, but these cilia displayed less labelling than dendrites and dendritic endings. Olfactory-marker protein was not found in apices and microvilli of neighboring olfactory-supporting cells.
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  • 55
    ISSN: 1432-0878
    Keywords: Subcommissural organ ; Glial markers ; Immunocytochemistry ; GABA uptake ; Comparative analysis ; Mammals (rat, cat, mouse, rabbit)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The subcommissural organ (SCO), classified as one of the circumventricular organs, is composed mainly of modified ependymal cells, attributable to a glial lineage. Nevertheless, in the rat, these cells do not possess glial markers such as glial fibrillary acidic protein (GFAP), protein S100, or the enzyme glutamine synthetase (GS). They receive a synaptic 5-HT input and show pharmacological properties for uptake of GABA resembling the uptake mechanism of neurons. In this study, we examine the phenotype of several mammalian SCO (cat, mouse, rabbit) and compare them with the corresponding features of the rat SCO. In all these species, the SCO ependymocytes possess vimentin as an intermediate filament, but never express GFAP or neurofilament proteins. They do not contain GS as do glial cells involved in GABA metabolism, and when they contain protein S100 (rabbit, mouse), its rate is low in comparison to classical glial or ependymal cells. Thus, these ependymocytes display characteristics that differentiate them from other types of glial cells (astrocytes, epithelial ependymocytes and tanycytes). Striking interspecies differences in the capacity of SCO-ependymocytes for uptake of GABA might be related to their innervation and suggest a species-dependent plasticity in their function.
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  • 56
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    Cell & tissue research 257 (1989), S. 343-366 
    ISSN: 1432-0878
    Keywords: Central complex ; Golgi impregnation ; Neurotransmitters ; Protocerebrum, insect ; Immunocytochemistry ; Drosophila melanogaster (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary On the basis of 1200 Golgi-impregnated brains the structure of the central complex of Drosophila melanogaster was analyzed at the cellular level. The four substructures of the central complex — the ellipsoid body, the fanshaped body, the noduli, and the protocerebral bridge — are composed of (a) columnar small-field elements linking different substructures or regions in the same substructure and (b) tangential large-field neurons forming strata perpendicular to the columns. At least some small-field neurons belong to isomorphic sets, which follow various regular projection patterns. Assuming that the blebs of a neuron are presynaptic and the spines are postsynaptic, the Golgi preparations indicate that small-field neurons projecting to the ventral bodies (accessory area) are the main output from the central complex and that its main input is through the large-field neurons. These in turn are presumed to receive input in various neuropils of the brain including the ventral bodies. Transmitters can be attributed immunocytochemically to some neuron types. For example, GABA is confined to the R1–R4 neurons of the ellipsoid body, whereas these cells are devoid of choline acetyltransferase-like immunore-activity. It is proposed that the central complex is an elaboration of the interhemispheric commissure serving the fast exchange of data between the two brain hemispheres in the control of behavioral activity.
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  • 57
    ISSN: 1432-0878
    Keywords: L1-antigen ; Cell adhesion molecule ; Developing vestibular neuroepithelium ; Immunocytochemistry ; Mouse (CBAxC57)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Doubts exist as to whether afferent nerve fibers exert a neurotrophic effect on the differentiation of sensory cells in the developing vestibular neuroepithelium. To determine whether innervation of hair cells precedes their differentiation, we have used the L1 adhesion molecule as a marker for axons. The detection of L1 on afferent axons in the otic vesicle of mouse embryos on gestation day 11 shows that nerve fibers penetrate the neuroepithelium before the sensory cells differentiate. L1-immunoreactivity of nerve endings also reveals the considerable fiber ramification on gestation days 14 and 15, i.e., corresponding to the first stages of sensory cell differentiation. The expression of L1 at successive stages of nerve fiber growth in the neuroepithelium, such as fasciculation and ramification, is not consistent with the previous role proposed for L1 as a fascicule-promoting factor and raises the possibility that other mechanisms are involved in L1 mediaded adhesion.
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  • 58
    ISSN: 1432-0878
    Keywords: Neuropeptides ; Immunocytochemistry ; Lumbricus terrestris (Annelida, Oligochaeta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The localisation and distribution of 10 vertebrate-derived neuropeptides in the earthworm, Lumbricus terrestris, have been determined by an indirect immunofluorescence technique. The peptides are pancreatic polypeptide (PP), peptide tyrosine tyrosine (PYY), neuropeptide Y (NPY), glucagon (C-terminal), vasoactive intestinal polypeptide (VIP), peptide histidine isoleucine (PHI), gastrinreleasing peptide (GRP), calcitonin gene-related peptide (CGRP), neurotensin (NT), and met-enkephalin. For 6 of the peptides — PYY, NPY, PHI, glucagon, GRP and CGRP — this is the first demonstration of their presence in any annelid, and NT has not previously been described in an oligochaete. Cell bodies and nerve fibres immunoreactive to the 10 peptides occur throughout the CNS. In the PNS, epidermal sensory cells displayed immunoreactivities to PP and PYY, and PP-, PYY-, NPY-, PHI- and GRP-like immunoreactivities occurred in nerve fibres supplying the main body muscles. Nerve fibres immunoreactive to PP and PYY are also associated with the innervation of the gut (pharynx, oesophageal glands, and mid and posterior regions of the intestine). No endocrine cells immunoreactive for any of the antisera tested could be identified in the gut epithelium, suggesting that dual location of peptides in the brain and gut epithelium is a phenomenon that occurred at a later stage in evolution. No immunoreactive elements were detected in any of the organs and ducts of the reproductive and excretory systems.
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  • 59
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    Cell & tissue research 255 (1989), S. 225-233 
    ISSN: 1432-0878
    Keywords: GABA ; Immunocytochemistry ; Visual system ; Optic lobes ; Periplaneta americana (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Specific antisera against protein-conjugated γ-aminobutyric acid (GABA) were used in immunocytochemical staining procedures to study the distribution of the putative GABA-like immunoreactive neurons in the optic lobes of Periplaneta. GABA-like immunoreactive structures are evident in all three optic neuropil regions. Six different populations of GABAergic neurons, whose perikarya are grouped around the medulla, are found within the optic lobe. The number of these immunoreactive cells varies greatly and corresponds to the number of ommatidia of the eye. In the proximal part of the lamina, a coarse network of GABA-positive fibres is recognizable. These are the processes of large field tangential cells whose fibres pass through the distal surface of the medulla. A second fibre population of the lamina is made up of the processes of the centrifugal columnar neurons whose perikarya lie proximally to the medulla. The medulla contains 9 layers with GABAergic elements of variable immunoreactivity. Layers 1, 3, 5, 7 and 9 exhibit strong labelling, as a result of partial overlapping of the processes of centrifugal and centripetal columnar neurons, tangential fibres and/or lateral processes of perpendicular fibres and (possibly) processes of amacrines. A strong immunoreactivity is found in the proximal and distal layers of the lobula.
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  • 60
    ISSN: 1432-0878
    Keywords: Serotonin (5HT) ; Immunocytochemistry ; 5,6-Dihydroxytryptamine ; Central nervous system ; Helix pomatia (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of serotonin (5HT)-containing neurons in the central nervous system of the snail Helix pomatia has been determined in whole-mount preparations by use of immunocytochemical and in vivo 5,6-dihydroxy-tryptamine labelling. 5HT-immunoreactive neuronal somata occur in all but the buccal and pleural ganglia. Immunoreactive fibres are present throughout the central nervous system. The 5HT-immunoreactive neuronal somata characteristically appear in groups, located mainly in the cerebral, pedal, visceral and right parietal ganglia. The majority of 5HT-immunoreactive neurons is located in the pedal ganglia. Additionally a dense network of 5HT-immunoreactive varicose fibres is found in the neural sheath of the central nervous system including all the nerves and ganglia. The number and distribution of 5HT-immunoreactive neurons correlates with that demonstrated by 5,6-dihydroxytryptamine labelling method.
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  • 61
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    Cell & tissue research 257 (1989), S. 545-548 
    ISSN: 1432-0878
    Keywords: Brush cells ; Fatty acid-binding protein ; Immunocytochemistry ; Stomach ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An immunocytochemical study by light- and electron microscopy using the antibody against rat hepatic fatty acid-binding protein (FABP) revealed the brush cells in the gastric epithelium of rats to be intensely immunoreactive. The immunoreactive cells were present in a group in the distal wall of the groove between forestomach and glandular stomach, as well as scattered singly in the surface and foveolar epithelia of the glandular stomach. Almost all immunoreactive brush cells had a thin basal process in contact with the basement membrane. No secretory granules with dense cores, similar to those of endocrine cells, were observed in the brush cells. The specific appearance of FABP-immunoreactivity in the brush cell indicates that this cell type is a distinct entity from other epithelial cells in the stomach and that FABP is a useful histochemical marker of the brush cells. FABP may be involved in the specific function(s) of this cell type related to fatty acid metabolism.
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  • 62
    ISSN: 1617-4623
    Keywords: Drosophila ; Vestigial ; Dihydrofolate reductase ; Aminopterin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Vestigial (vg) mutants of Drosophila melanogaster are characterized by atrophied wings. In this paper we show that: (1) aminopterin an inhibitor of dihydrofolate reductase (DHFR) and fluorodeoxyuridine (FUdR), an inhibitor of thymidylate synthetase induce nicks in the wings of wild-type flies and phenocopies of the vg mutant phenotype when vg/+ and vg B/+ flies are reared on these substances (vgB is a deficiency of the vg locus). Only thymidine and thymidylate can rescue the flies from the effect of aminopterin. We propose that the vg phenotype is due to a decrease in the dTMP pool in the wings. (2) Mutant vg strains yield more offspring on medium containing aminopterin than on normal medium. The resistance of vg larvae to the inhibitor seems specific to the gene. This is the first case of aminopterin resistance in living eucaryotes. In contrast sensitivity of the vg larvae to FUdR is observed. (3) An increase in the activity and amount of DHFR is observed in mutant strains as compared with the wild-type flies. Our data suggest that the vg + gene is a regulatory gene acting on the DHFR gene or a structural gene involved in the same metabolic pathway.
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  • 63
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    Molecular genetics and genomics 218 (1989), S. 118-126 
    ISSN: 1617-4623
    Keywords: Drosophila ; Regulation ; yellow gene ; Germline transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have assessed the DNA sequence requirements for the correct spatial pattern and phenotypic expression of y in the late embryo/larvae. The wild-type larval phenotype requires both the regions between-294 bp and-92 bp and a portion of the intron; the sequence element(s) located within the intron can act in a position independent manner to effect the wild-type larval phenotype. The larval expression pattern was examined by tissue experiments in situ and by staining germline transformants derived from various y/lacZ fusion constructs. The larval expression of y is restricted to the mouthparts, microsetae and anal plates. While the-495 bp to+194 bp region alone cannot effect a wild-type larval expression pattern, this region in conjunction with the intron appears to be sufficient to drive β-gal expression in an essentially wild-type pattern. Our data further suggest that the-294 bp to-92 bp region contains elements which specify the larval pattern and that the element(s) in the intron normally act to enhance the level of expression necessary for the wild-type larval phenotype. We also present a phenotypic analysis of the adult cuticle structures of germline transformants derived from a variety of deletion and rearrangement constructs of the y gene. This analysis has revealed several new features associated with the regulation of y expression.
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  • 64
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    Molecular genetics and genomics 215 (1989), S. 281-285 
    ISSN: 1617-4623
    Keywords: Drosophila ; achaete-scute complex ; myc ; Protein domains ; Genomic search
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Several genes of the achaete-scute complex (ASC) of Drosophila melanogaster encode a 60 amino acids long conserved domain which shares a significant homology with a region of the vertebrate myc proteins. Based on these results, the existence of a family of Drosophila genes that would share both this conserved domain and the neurogenic function of the AS-C has been postulated. To test this proposal, we have searched a D. melanogaster genomic library with a probe that encodes the conserved domain. Only under very low stringency hybridization conditions, clones not belonging to the AS-C cross-hybridized with the probe. Those that gave the strongest signals were characterized. Sequencing of the cross-hybridizing regions showed that they had no significant homology with the conserved domain, the sequence similarity extending at the most for 37 nucleotides. Although our results do not conclusively disprove the existence of a family of AS-C-like genes, they indicate that the conservation of the domain would be lower than that found for shared motifs in other families of Drosophila developmental genes.
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  • 65
    ISSN: 1615-6102
    Keywords: Pyrenoid ; Ribulose 1,5-bisphosphate carboxylase/oxygenase ; Chlorella pyrenoidosa ; Immunocytochemistry
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    Topics: Biology
    Notes: Summary The localization of ribulose 1,5-bisphosphate carboxylase/ oxygenase (RuBisCO) in cells ofC. pyrenoidosa grown at varying light intensities was determined by immunoelectron microscopy. Log phase cells grown at photon flux densities of 25 and 75 μEm−2s−1 (light-limiting) and 540 μEm−2s−1 (light-saturating) were fixed in 3% glutaraldehyde and embedded in Lowicryl K4M. Sections were labelled with antiserum to each subunit of RuBisCO followed by protein A-gold. At each light fluence rate, the pyrenoid was heavily labelled by each antibody whereas chloroplast stromal labelling was not above background levels. The apparent absence of stromal RuBisCO at each light level, and hence the lack of enzyme redistribution from pyrenoid to stroma following an increase in light fluence rate, suggests that pyrenoid RuBisCO is functional in vivo.
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  • 66
    ISSN: 1573-8477
    Keywords: Genetic elements ; isozymes ; life span ; Drosophila
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    Topics: Biology
    Notes: Summary Analysis of electrophoretic loci shows that at least four differences exist in isozymes of long- and short-lived populations ofD. melanogaster, descended by selection from a common ancestral stock. Adults of longlived populations differ in gene dosage of phosphoglucomutase (PGM), NAD malate dehydrogenase (MHD), NADP malic enzyme (ME) and by additional mobility variants of glucose-6-phosphate dehydrogenase (G6PD). Larvae, however, differ only by variants of G6PD. The differences in these enzymes, considered together with the greater flight endurance that long-lived populations have shown elsewhere, suggest that increased glycogen synthesis plays a significant role in the improved life span of selected populations. Adaptation to selection for increased life span may, therefore, derive from an improved ability to use dietary sucrose in the media provided. The distribution of electrophoretic loci agrees with the results of a study indicating the position of genetic elements contributing to life span.
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  • 67
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    Evolutionary ecology 3 (1989), S. 189-201 
    ISSN: 1573-8477
    Keywords: Developmental homeostasis ; life history traits ; Drosophila ; breeding site variation ; cactus ; Sonoran desert
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Variation in life histories among populations of cactophilicDrosophila mojavensis has been hypothesized to be a by-product of a shift to one of two alternate host plants. When cultured on the ancestral and a secondary host cactus, a Baja population expressed shorter development times and smaller thorax sizes than a mainland population, but viability did not differ. Comparisons with all reciprocal F1 and F2 crosses between populations revealed that genetic differences in development time and thorax size were largely additive. Homeostasis in these life history traits was population specific, except for viability. Homeostasis in development time was greater in the Baja population than in the other crosses, suggesting dominance for decreased homeostasis in the mainland population. Underdominance in viability homeostasis of the F1 hybrids suggested some incompatibility between populations. Homeostasis in thorax size was greater in females than in males and differed among parental populations. Maintenance of heritable differences and genetic variation for homeostasis in these traits suggested a role for cactus-specific differences in environmental uncertainty caused by variation in breeding site duration and abundance in nature.
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  • 68
    ISSN: 1617-4623
    Keywords: Chromosomal walking ; Cut locus ; Drosophila ; Unstable mutations
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    Topics: Biology
    Notes: Abstract We have cloned from the Oregon R strain of Drosophila melanogaster a 240 kb segment of DNA that contains the cut (ct) locus, and characterized the region for the presence of repetitive elements. Within this region at least five copies of the suffix element were detected, as well as several putatively novel mobile elements. A number of mutations obtained from the unstable ct MR2 strain and its derivatives were mapped within the cut locus. Comparison between parental and daughter strains indicates that frequently two or more independent transposition events involving the cut locus occur simultaneously within a single germ cell, thus providing a molecular basis for the transposition explosion phenomenon.
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  • 69
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    Molecular genetics and genomics 219 (1989), S. 397-403 
    ISSN: 1617-4623
    Keywords: Drosophila ; Pyrimidine biosynthesis ; Dihydroorotate dehydrogenase ; Molecular mapping
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    Topics: Biology
    Notes: Summary The dhod locus encodes dihydroorotate dehydrogenase, the fourth enzymatic step of de novo pyrimidine biosynthesis. This locus was cloned previously by a chromosome walk in cytogenetic region 85A. The location of dhod within 85A DNA has been determined by mapping two rearrangement mutations to a small DNA region. A nearly full-length cDNA clone of the dhod transcript was isolated and partially sequenced, to confirm its identity. The cDNA clone was also used to map the transcribed DNA. A 1.5 kb dhod RNA is described which is most abundant in embryos and displays minor length heterogeneity in pupae and adults. The developmental expression of this transcript is discussed relative to the expression of dihydroorotate dehydrogenase activity and other genes of the pyrimidine biosynthetic pathway.
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  • 70
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    Molecular genetics and genomics 215 (1989), S. 190-199 
    ISSN: 1617-4623
    Keywords: Mutagen sensitivity ; Recombination ; Gene structure ; Drosophila ; mei-41
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    Topics: Biology
    Notes: Summary The mutagen-sensitive mutant mus(1)104 D1 of Drosophila melanogaster maps to a position on the X chromosome very close to the meiotic mutant mei-41 D5 . Both mutants have been characterized as mutagen-sensitive and defective in post-replication repair. In the present report we show by complementation studies that mus(1)104 and mus(1)103 are allelic with mei-41. In addition, two reported alleles of mus(1)104 lie between the mei-41 alleles A10 and D5. The size of the mei-41 locus is estimated to be about 0.1 centimorgans (cM). Because several alleles of mei-41 have been shown to reduce recombination and increase meiotic chromosome loss and nondisjunction, mus(1)104 D1 females were examined for defects in meiosis. Although there was no evidence for reduced recombination on the second chromosome in homozygous mus(1)104 D1 females, heterozygous mus(1)104 D1 /mei-41 〉D5 and mus(1)104 D1 /deficiency females showed reduced levels of recombination. However, there was no evidence of an increase in nondijunction in these females.
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  • 71
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    Molecular genetics and genomics 215 (1989), S. 257-265 
    ISSN: 1617-4623
    Keywords: Drosophila ; Maternal effect ; Syngamy ; Embryonic development ; Molecular cloning
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    Topics: Biology
    Notes: Summary The maternal effect locus fs(1) Ya is required for the fusion of the apposed sperm and egg pronuclei (syngamy) following fertilization in Drosophila. It is tightly linked to another complementation group, fs(1) Yb, needed for both oogenesis and embryogenesis. We have isolated a set of overlapping cloned sequences in the 3B4-6 region of the X chromosome encompassing the fs(1) Ya-fs(1) Yb region. A single 2.4 kb maternal transcript is encoded with-in this region, and an 8.5 kb DNA fragment that contains this transcript complements both fs(1) Ya and fs(1) Yb mutations. Northern and in situ hybridization analyses show that the maternal transcript is only present in nurse cells and oocytes beginning in previtellogenic stages, and is evenly distributed in the cytoplasm of 0–2 h syncytial embryos. The transcript is not detected in later stages of embryonic development. This expression pattern correlates closely with the genetic and developmental characteristics expected of the fs(1) Ya gene product.
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  • 72
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    Molecular genetics and genomics 215 (1989), S. 469-477 
    ISSN: 1617-4623
    Keywords: Drosophila ; Y chromosome ; Repetitive DNA ; Testis RNA ; Transposable elements
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    Topics: Biology
    Notes: Summary A cDNA clone bank was constructed from testis poly(A)+ RNA of Drosophila hydei and screened for clones which hybridize to Y chromosomal DNA sequences. The insert of clone cDhT14 hybridizes to a family of repeated DNA sequences with members distributed within the Y chromosome and elsewhere in the genome. This type of sequence has earlier been described as the Y-associated class of DNA. Southern blot analysis of DNA from different wild-type strains of D. hydei suggests that members of the T14 family of repeated DNA sequences are parts of a family of transposable elements. The genomic localization of the T14 family of repeated DNA sequences was revealed by in situ hybridization to metaphase and polytene chromosomes, and to transcripts of Y chromosomal lampbrush loops. Approximately 10–15 members (20%–30%) of the T14 sequence family reside in 8.3 kb PstI restriction fragments. A genomic clone of one of these DNA fragments, DhT14-8.3, hybridizes to transcripts on the Y chromosomal lampbrush loop “cones”, and in conventional in situ hybridization experments to region 12D/13A of the X chromosome and to region 112 of chromosome 5. The cDNA clone cDhT14 represents a part of an abundant testis RNA species of 5.0 kb. This RNA is also present in ovaries and in 0–3 h, 3–6 h and 6–12 h embryos, but less abundantly than in testes. Both the Y chromosomal site of the 8.3 kb PstI fragments and sites elsewhere in the genome are actively transcribed. At least one of the latter genomic sites is transcribed into the 5.0 kb RNA species. This poly(A)+ RNA is present in the cytoplasm of primary spermatocytes as shown by transcript in situ hybridization. The potential function of transcripts from Y chromosomal lampbrush loops is discussed.
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  • 73
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    Journal of comparative physiology 159 (1989), S. 237-242 
    ISSN: 1432-136X
    Keywords: Amylase ; Mosquitofish ; Rat ; Drosophila ; Structure ; Function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Amylases from the mosquitofish (Gambusia affinis holbrooki, Pisces: Poeciliidae) and rat were purified and compared withDrosophila amylases in terms of structure and function. At the structural level, amino acid compositions of the three amylases were compared. At the functional level, amylase activities were compared on various substrates and in the presence of inhibitors. While the amylases from all three organisms had properties typical of alpha-amylases, both structural and functional differences were observed. Using resemblance coefficients of distance and similarity from numerical taxonomy, it was determined that the amylases from the rat andDrosophila were more similar to each other than either was to amylase from the mosquitofish, and that structural differences between the amylases did not reflect functional differences, i.e. there was no correlation between amylase structural and functional distances.
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  • 74
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    Journal of chemical ecology 15 (1989), S. 663-676 
    ISSN: 1573-1561
    Keywords: Drosophila ; Diptera ; Drosophilidae ; triterpene glycosides ; cactus ; fitness components ; host-plant relationships
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The effects of pentacyclic triterpene glycosides extracted from agria and organ pipe cacti on three fitness parameters of the cactophilic fruit fly,Drosophila mojavensis were tested. Triterpene glycosides from organ pipe increased development time and reduced larval viability while those from agria produced smaller adults (reduced fecundity). In addition, the microbial communities in the organ pipe saponin media were less dense than those in the media to which agria saponins had been added. The role of cactus triterpene glycosides in the ecology of thisDrosophila species is discussed.
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  • 75
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    Journal of insect behavior 1 (1988), S. 3-15 
    ISSN: 1572-8889
    Keywords: host preference ; habitat selection ; experience ; learning ; Drosophila ; host races ; population genetics
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    Topics: Biology
    Notes: Abstract A field experiment with Drosophila melanogasterrevealed that when flies encounter a particular food type soon after emergence, the probability of their subsequently being attracted to such a resource is increased. In this experiment, the length of time flies experienced their postemergence environments was under the control of the flies themselves. The experiment thus realistically mimicked one form of experiential effect that may be important in nature. A theoretical model is developed which shows that enhanced adult preferences for the types of resources fed on as larvae can substantially increase the degree of host-based genetic subdivision within a polyphagous population.
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  • 76
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    Entomologia experimentalis et applicata 47 (1988), S. 81-88 
    ISSN: 1570-7458
    Keywords: imaginal diapause ; male mating activity ; genetics ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les femelles de D. triauraria Bock & Wheeler (Dipt. Drosophilidae) sont connues pour présenter une diapause reproductrice aux photophases courtes. Les mâles eux aussi ont révélé une activité sexuelle réduite aux photophases courtes, c'est-à-dire qu'ils sont entrés comme les femelles en diapause reproductive. Les photophases critiques pour l'induction de la diapause des mâles et des femelles n'ont pas présenté de différences. Les diapause des mâles et des femelles s'achèvent même sous courtes photophases, mais la diapause mâle était quelque peu plus faible que la diapause femelle. La photophase critique et le taux de diapause ont varié en fonction de l'origine géographique dans l'espèce actuelle. Lors de croisements entre lignées diapausantes et non-diapausantes, la photophase critique et la durée de la diapause ont été héritées quantitativement. A partir de ces expériences et d'expériences précédentes de croisements (Kimura, 1983), quelques modèles de méchnisme d'induction de la diapause de cette espèce sont proposés.
    Notes: Abstract In Drosophila triauraria Bock & Wheeler (Diptera: Drosophilidae) of which females were known to enter reproductive diapause at short daylengths, males also showed reduced mating activity at short daylengths, i.e., males as well as females entered reproductive diapause. The critical daylength for diapause induction did not differ between females and males. Both male and female diapause ended even under short daylengths, but the male diapause was somewhat weaker than the female diapause. The critical daylength and the diapause rate varied geographically in this species. In the cross between diapausing and non-diapausing strains, the critical daylength and the diapause duration inherited in a quantitative manner. On the basis of the present and previous crossing experiments, some models are proposed on the mechanism of diapause induction of this species.
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    Journal of molecular evolution 28 (1988), S. 145-150 
    ISSN: 1432-1432
    Keywords: Alcohol dehydrogenase ; Drosophila ; Enzyme kinetics ; Product inhibition ; Microevolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Because natural populations ofDrosophila melanogaster are polymorphic for different allozymes of alcohol dehydrogenase (ADH) and becauseD. melanogaster is more tolerant to the toxic effects of ethanol than its sibling speciesD. simulans, information regarding the sensitivities of the different forms of ADH to the products of ethanol degradation are of ecological importance. ADH-F, ADH-S, ADH-71k ofD. melanogaster and the ADH ofD. simulans were inhibited by NADH, but the inhibition was relieved by NAD+. The order of sensitivity of NADH was ADH-F〈ADH-71k, ADH-S〈ADH-simulans with ADH-F being about four times less sensitive than theD. melanogaster enzymes and 12 times less sensitive than theD. simulans enzyme. Acetaldehyde inhibited the ethanolto-acetaldehyde activity of the ADHs, but at low acetaldehyde concentrations ethanol and NAD+ reduced the inhibition. ADH-71k and ADH-F were more subject to the inhibitory action of acetaldehyde than ADH-S and ADH-simulans, with ADH-71k being seven times more sensitive than ADH-S. The pattern of product inhibition of ADH-71k suggests a rapid equilibrium random mechanism for ethanol oxidation. Thus, although the ADH variants only differ by a few amino acids, these differences exert a far larger impact on their intrinsic properties than previously thought. How differences in product inhibition may be of significance in the evolution of the ADHs is discussed.
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    Development genes and evolution 197 (1988), S. 19-26 
    ISSN: 1432-041X
    Keywords: Drosophila ; Morphogenesis ; Appendages
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The phenotype of rotund (rn) null alleles is described, and compared to wild type. The mutants are expressed zygotically and cause position specific defects in certain imaginal discs (antenna, legs, wing, haltere and proboscis) and their corresponding adult derivatives. In the discs, specific folds are absent in rn mutants compared to wild type. Clonal analysis shows that the rn + gene is partially autonomous in its expression in cells destined to form certain distal parts of the adult appendages. The results are consistent with the idea that the rn + gene is required for normal morphogenesis of specific distal parts of the adult appendages.
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    Development genes and evolution 197 (1988), S. 40-48 
    ISSN: 1432-041X
    Keywords: Drosophila ; Homeosis ; Tumorous-head ; Bithorax-complex mutant ; Morphology
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    Topics: Biology
    Notes: Summary Transformations of tumorous-head Drosophila melanogaster were examined in order to investigate whether head structures were replaced by specific abdominal structures. Heads selected for the presence of genital structures were analyzed in detail. Female abnormalities included any combination of vaginal teeth, vulvar papillae, sensilla trichodea, abdominal tergites 6 (T6), 7 (T7), 8 (T8) and anal plate. Anal plate was observed in the prefrons and rostral membrane, while all other genital structures were intimately associated with modified shingle cuticle. Male abnormalities included transformation of antennal structures to penis, clasper teeth, lateral plate, anal plate and eye to T6. The distribution of each type of homeotic structure was confined to general regions of the eye-antenna, with no precise dividing lines between them. However, the spatial sequence of homeotic structures in the eye-antenna was generally the same as the sequence of the same structures in the posterior abdomen.
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    Development genes and evolution 197 (1988), S. 457-470 
    ISSN: 1432-041X
    Keywords: Neurogenesis ; Neurogenic genes ; Achaetescute complex ; Daughterless ; Genetic interactions ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In Drosophila melanogaster the neuroblasts separate from epidermoblasts to give rise to the neural primordium. This process is under the control of several genes. The group of the so-called neurogenic genes is required for epidermal development; other genes, comprising those of the achaete-scute complex and daughterless, are required for neural development. We have studied the relationships between both groups of genes in two different ways. We have analyzed the phenotype of double-mutant embryos and our results show that the neural hyperplasia caused by neurogenic mutations can be partially prevented if a mutation in one of the other genes is present in the same genome. Only the neural cells that do not require the function of a particular gene of the achaete-scute complex in the wild-type seem to develop to a neural fate in the double mutant embryos. At least some of the genetic interactions affect the transcriptional level, as shown by in situ hybridization, since the territories of transcription of the achaetescute genes are expanded in neurogenic mutants. All cells of the neurogenic region of the double mutants apparently initiate neural development. However, during later development some of these cells switch their fate either to epidermogenesis or to cell death and this leads to the final phenotype of the double mutants. We discuss these results with respect to the events of early neurogenesis.
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  • 81
    ISSN: 1432-041X
    Keywords: Drosophila ; shibire ; Neuronal development ; Muscle ; Giant fiber pathway
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    Topics: Biology
    Notes: Summary The temperature-sensitive mutation shibire (shi) in Drosophila melanogaster is thought to disrupt membrane recycling processes, including endocytotic vesicle pinch-off. This mutation can perturb the development of nerves and muscles of the adult escape response. After exposure to a heat pulse (6 h at 30° C) at 20 h of pupal development, adults have abnormal flight muscles. Wing depressor muscles (DLM) are reduced in number from the normal six to one or two fibers, and are composed of enlarged fibers that appear to represent fiber fusion; large spaces devoid of muscle fibers suggested fiber deletion. The normal five motor axons are present in the peripheral nerve PDMN near the ganglion. However, while some motor axons pass dorsally to the extant fibers, other motor axons lacking end targets pass into an abnormal posterior branch and terminate in a neuroma, i.e., a tangle of axons and glia without muscle target tissue. Hemisynapses are common in axons of the proximal PDMN and within the neuroma, but they are rarely seen in control (no heat pulse) shi or wild-type flies. All surviving muscle fibers are innervated; no muscle tissue exists without innervation. Fibrillar fine structure and neuromuscular synapses appear normal. Fused fibers have dual innervation, suggesting correct and specific matching of target tissue and motor axons. Motor axons lacking target fibers do not innervate erroneous targets but instead terminate in the neuroma. These results suggest developmental constraints and rules, which may contribute to the orderly, stereotyped development in the normal flight system. The nature of the anomalies inducible in the flight motor system in shi flies implies that membrane recycling events at about 20 h of pupal development are critical to the formation of the normal adult nerve-muscle pattern for DLM flight muscles.
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  • 82
    ISSN: 1432-041X
    Keywords: Cell interactions ; Cell commitment ; Neurogenesis ; Drosophila
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    Topics: Biology
    Notes: Summary Cell-cell interactions are involved in mediating developmental fate. An example is the decision of the neuroectodermal cells of Drosophila to develop as neural or epidermal progenitors, where cellular interactions participate in the process of acquisition of either cell fate. The results of heterochronic cell transplantations we describe here suggest that both neuroblasts and epidermoblasts are not irreversibly committed to a particular developmental fate. Rather, they retain the ability to interact with neighbouring cells and, under our experimental conditions, are capable of switching their fate during a relatively long period of time, i.e. until the end of embryonic stage 11.
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    Development genes and evolution 197 (1988), S. 435-440 
    ISSN: 1432-041X
    Keywords: Drosophila ; Homoeotic genes ; Segment differentiation
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary Regulator of bithorax (Rg-bx)−, or trithorax (trx)− lethal larvae occasionally show a homoeotic transformation of the dorsal prothorax to mesothoracic structures. This transformation suggests a reduced activity of the Sex combs reduced (Scr) gene on the basis of gene dosage studies, as well as enhanced expression of the phenotypes of the weak Scr − alleles in Rg-bx − larvae. Morphological observations of adult flies doubly heterozygous for Rg-bx and Scr mutations also suggest the enhancement of an aspect of Scr adult phenotypes. I conclude that the Rg-bx + gene function is required for the optimal expression of the Scr gene in larval and imaginai cells.
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    Development genes and evolution 197 (1988), S. 507-512 
    ISSN: 1432-041X
    Keywords: Drosophila ; Reporter gene ; hairy ; Segmentation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Random insertions of a promotor fused to a reporter gene, such as Lac-Z, reveal regulatory sequences that confer temporal and spatial patterns of gene expression in eukaryotes. These patterns may reflect the activity of a neighbouring gene and thus lead to the isolation of new genes essential for normal development. Here, we demonstrate that this hypothesis is true for an insertion into the well characterized segmentation gene, hairy, in Drosophila. The insertion is homozygous lethal and fails to complement other hairy alleles, giving the phenotype described for hairy mutations. The insertion is located at 66D on the polytene chromosome map, is within 300–600 bp 5′ to the first hairy exon, and is orientated in the same sense (5′-3′) as the hairy transcription unit. Expression of β-galactosidase (β-gal), deriving from the insertion, follows closely the spatio-temporal patterns of expression of hairy gene product during embryogenesis. In addition, other sites of β-galactosidase expression are shown in the third larval instar stage and in the adult ovary. The results show that some insertions, giving restricted patterns of reporter gene expression, will reflect the temporo-spatial activity of a nearby gene.
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  • 85
    ISSN: 1432-041X
    Keywords: Drosophila ; Injection of embryo ; Daudi conditioned medium ; Rudimentary ovaries ; Mean number of ovarioles
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    Topics: Biology
    Notes: Summary Drosophila melanogaster embryos were injected before the blastoderm stage with conditioned media from several male Burkitt's lymphoma human cell lines and the Daudi cell line. Such injections do not have any effect on the male genital apparatus or on the female tract. The Daudi conditioned medium modifies the ovarian morphogenesis of the flies and the rudimentary ovaries obtained look like nymphal gonads. Moreover, they have a drastically reduced number of germ cells. The ovaries that looked functional contain numerous necrotic germ cells and the mean number of ovarioles per fly is significantly smaller than that of the controls. The abnormalities observed resemble the results of experimental and genetic lack of germ cells. They disappear at very high dilution (1×10−6).
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    Development genes and evolution 197 (1988), S. 231-238 
    ISSN: 1432-041X
    Keywords: Drosophila ; Electrical polarity ; Ovarian follicles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Distribution of rhodamine-conjugated lysozyme injected into the sixteen-cell syncytium comprising the germ-line portion of theDrosophila follicle is shown to be affected by charge. Positive molecules are able to migrate through intercellular bridges from the oocyte to the nurse cells, but are unable to migrate detectably from nurse cells to the oocyte. Their negatively charged counterparts can move from the nurse cells to the oocyte, but are unable to traverse the intercellular bridges in the counter direction. This charge-dependent movement of molecules is accompanied by an electrical potential difference, focused across the nurse cell-oocyte bridges, which makes the nurse cells negatively charged to the oocyte. The addition of insect hemolymph to the physiological salt solution in which the experiments were performed resulted in only a small increase in the transmembrane resistance, but enhanced the potential difference between oocyte and nurse cells from 0.2±0.3 (SE) mV (nurse cells negative) to 2.3±0.45 (SE) mV (nurse cells negative).
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  • 87
    ISSN: 1432-041X
    Keywords: Drosophila ; Homeosis ; Epidermal development ; Embryology ; Clonal analysis
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary The complex genetic locuspolyhomeotic (ph) is a member of thePolycomb (Pc)-group of genes and as such is required for the normal expression of ANT-C and BX-C genes. It also has probably other functions since amorphicph alleles display a cell death phenotype in the ventral epidermis of 12-h-old embryos. Here it is shown that lethal alleles ofph (amorph and strong hypomorph) show transformation of most of their segments towards AB8. Theph + product is required autonomously in imaginal cells. The total lack ofph + function prevents viability of the cuticular derivatives of these cells.ph has a strong maternal effect on segmental identity and epidermal development that can not be rescued by one paternally supplied dose ofph + in the zygote. These phenotypes differ substantially from those of previously describedPc-group genes. AmongPc-group genes,ph seems to be the only one that is strongly required both maternally and zygotically for normal embryonic development.
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  • 88
    ISSN: 1432-041X
    Keywords: Drosophila ; Ultrabithorax ; Development ; Regulation ; Protein distribution
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary Most viable alleles of homeotic genes cause partial transformations within given lineages in a topographically specific fashion. We study this phenomenon as a way to understand the normal mechanisms involved in the spatial regulation of homeotic gene expression. To this end we have investigated the distribution of Ultrabithorax (Ubx) proteins in imaginai discs mutant for hypomorphic and neomorphic alleles of Ubx and alleles of trans-acting genes. We find that the morphological discontinuities observed in the adult transformations are caused by corresponding new patterns of the Ubx proteins in the imaginai anlagen. These novel patterns of Ubx proteins are understood as a consequence of a process of reinforcement-extinction of Ubx expression. The evidence suggesting that this process results from a positive feed-back loop and cell-cell interactions is discussed.
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  • 89
    ISSN: 1432-041X
    Keywords: Bithorax complex ; Drosophila ; Abdominal-B mutations ; Genetic mosaics
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    Topics: Biology
    Notes: Summary The phenotypic effects in imaginal hypodermal tissue of a number of Abdominal-B mutations of the bithorax complex are described. Evidence is given from complementation analysis that the phenotypic heterogeneity in both the spatial limits and the nature of the homeotic transformations produced is not an arbitrary classification of allelic differences that we find. We have used genetic mosaic analysis to support the interpretation that the Abdominal-B genetic unit can exist in a number of alternative functional states of expression during development and that individual Abdominal-B mutations may abolish some states whilst leaving others unaffected.
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  • 90
    ISSN: 1432-041X
    Keywords: Drosophila ; Segment polarity gene ; Maternal effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Fused is a segmentation gene belonging to the segment-polarity class. Mutations at thefused locus are known to display pleiotropic effects, causing zygotically determined anomalies of ovaries and of some adult cuticular structures, and maternally determined embryonic segmentation defects. In order to determine the amorphic phenotype offused and to study the genetical basis of its pleiotropy, newfused alleles (18 viable and 11 lethal) were isolated. The phenotype of these mutants and of others already known are described, taking into account zygotic and maternal effects. The main results provided by this analysis are as follows. Firstly, allfused alleles show the whole complex fused phenotype, and a good correlation is observed between the strength of the wing and segmentation defects, suggesting that a single function is involved in both processes. Secondly, all embryonic and larval lethals carry deficiencies which allow us to localizefused between the 17C4 and 17D2 bands of the X-chromosome. Thirdly, the 24 viable and 2 pupal lethals examined behave as point mutants, as shown cytologically or by Southern blot analysis. However, only one of them, the pupal lethalfu mH63 was proven to carry a nullfused allele, since it displays in germ-line clones a strong maternal phenotype and a very low zygotic rescue, similar to those of the small deficiencyDf(1)fu z4. The phenotype of the amorphic mutant indicates that zygotic ezpression offused is required for normal metamorphosis, while maternal expression is necessary for a normal segmentation pattern, since a complete loss offused expression during oogenesis cannot be compensated zygotically.
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  • 91
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    Development genes and evolution 197 (1988), S. 75-91 
    ISSN: 1432-041X
    Keywords: Drosophila ; Maternal effect mutation ; Pattern formation ; Gastrulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The gastrulation defective (gd) locus is a maternally expressed gene in Drosophila required for normal differentiation of structures along the embryonic dorso-ventral axis. Cuticular defects of the offspring from females with different combinations of gd alleles comprised a phenotypic continuum. Complementation among several alleles produced normal offspring while progressively more severe mutations produced a graded loss of structures from ventral, and then lateral, blastoderm cells. The most severely affected embryos consisted entirely of structures derived from dorsal blastoderm cells. Histological examination of staged siblings from selected allelic combinations showed that internal tissues were similarly affected. The tissues observed in amorphic embryos support new, more dorsal, assignments of fate map positions for blastoderm precursors of the cephalopharyngeal apparatus, hindgut and ventral nerve cord. The loss of ventral and lateral structures did not occur through cell death and appeared to involve a change in blastoderm cell fate. A direct effect of the mutations on blastoderm cell determination, however, was insufficient to explain the development of the dorsalized embryos. Intermediate phenotypes suggested that cell interactions or movements associated with morphogenesis are required for the determination of some cell fates in the dorsoventral axis. Thus, the developmental fate of all blastoderm cells may not be fixed at the time of blastoderm formation.
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  • 92
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    Development genes and evolution 197 (1988), S. 115-123 
    ISSN: 1432-041X
    Keywords: X-Chromosome Loci ; Dominant maternal effect ; Segmentation genes ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A systematic search for X chromosome loci showing a dominant maternal interaction with the segmentation genes Krüppel, hunchback, knirps and hairy was performed using deficiencies spanning 65% of the X chromosome. No interaction with the knirps gene was observed, but five regions of the X chromosome showed a maternal dominant interaction with the Krüppel gene. Two of these regions also show a maternal dominant interaction with either hunchback (region 10A7–10A8) or hairy (region 10E1–10F3). In all of these interactions dead embryos were observed which showed the same defects as embryos homozygous for the segmentation gene tested. These results suggest that a complex repartition of maternal products necessary for subsequent segmentation may occur in the Drosophila egg.
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  • 93
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    Oecologia 75 (1988), S. 400-404 
    ISSN: 1432-1939
    Keywords: Vectoring ; Drosophila ; Cactophilic yeasts ; Dispersal ; Community structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary At two locations in the Sonoran Desert, yeasts were sampled from species of Drosophila, the flies' cactus hosts, and other neighboring sources of cactophilic yeasts to determine the relation between the yeasts vectored by the fly and the yeasts found in their breeding sites. D. mojavensis, D. nigrospiracula, and D. mettleri vectored yeast assemblages significantly more similar to the yeast species found on the rot from which the flies were collected than to the yeasts found on other rots from the flies host cactus or other rotting cactus at the same site. Rots with Drosophila had fewer yeast species than those without flies, suggesting that flies were associated with younger rots. Rots with flies and the Drosophila also had more yeast species with the capability to produce ethyl acetate than rots without flies. The results support the contention that cactophilic Drosophila feed on a subset of the yeasts available in an area, and may act to maintain differences among the yeast communities found on different species of cactus.
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  • 94
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    Oecologia 75 (1988), S. 516-520 
    ISSN: 1432-1939
    Keywords: Drosophila ; Picornavirus ; Fertility ; Embryonic and larvo-pupal death rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Drosophila C virus (DCV) has a considerable impact on ovarian morphogenesis inDrosophila melanogaster host populations. This virus also affects the developmental time and the fresh weight of infected females. In order to investigate the hypothesis that DCV may play a role in the dynamics ofDrosophila populations, the fertility and embryonic and larvo-pupal death rates of a host population and that of five DCV-free populations were determined. A comparison of two populations, one of them DCV-free, the other infected, suggested that the fertility of the DCV-infected flies was higher than that of uninfected flies, despite a greater larvo-pupal death rate. Fertility of the infected flies was greater among the infected population than for the DCV-free populations. The DCV-free populations originated from five different localities. The virus clearly does have an impact on the biotic potential of its host population. This paper reports for the first time a positive interaction between a viral population and a host population as it increases certain parameters of host population dynamics.
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  • 95
    ISSN: 1432-072X
    Keywords: Acidaminococcus fermentans ; Glutamate fermentation ; Electron microscopy ; Immunocytochemistry ; Post-embedding labelling ; Antibody-gold complexes ; Protein A-gold complexes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have investigated the in situ location of glutaconyl-CoA decarboxylase and 2-htdroxyglutaryl-CoA dehydratase in Acidaminococcus fermentans using the antibody-gold and protein A-gold techniques carried out as a post-embedding immunoelectron microscopic procedure. Polyclonal antisera were raised in rabbits against homogeneous fractions of the enzymes. Anaerobically grown cells of A. fermentans of the late exponential growth phase were fixed with 0.2% glutaraldehyde and 0.3% formaldehyde (final concentrations) in the growth medium. Dehydration of the cells was achieved with methanol. The cells were embedded in the low temperature embedding resin Lowicryl K4M. The markers indicative for antigenic sites of the two enzymes unequivocally demonstrate that the sodium pump glutaconyl-CoA decarboxylase is located at the cell periphery being a membrane-bound enzyme as expected whereas 2-hydroxyglutaryl-CoA dehydratase is a soluble cytoplasmic enzyme.
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  • 96
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    Biochemical genetics 26 (1988), S. 131-141 
    ISSN: 1573-4927
    Keywords: Drosophila ; arginine kinase ; mitochondria ; isozymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Mitochondrial and cytoplasmic isozymes of arginine kinase have been identified inDrosophila melanogaster. On the basis of their immunological similarity, parallel dosage responses, and cosegregation of electrophoretic mobility differences, it is concluded that both isozymes are the product of a single gene. The consequences of this in relation to the regulation and evolution of this unusual gene-enzyme system are discussed. It is inferred that the origin of the phosphagen shuttle must predate the divergence of invertebrates and vertebrates.
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  • 97
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    Biochemical genetics 26 (1988), S. 783-803 
    ISSN: 1573-4927
    Keywords: Drosophila ; dipeptidase activities ; genetic variation ; activity modifiers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract An examination ofDrosophila melanogaster from natural populations revealed genetic variation for dipeptidase-A (DIP-A) and dipeptidase-B (DIP-B) activities within sets of lines that differed from one another only in the second or the third chromosome. Analyses of diallel crosses indicate that both activities are inherited additively, and coordinate control of expression is suggested by the significant positive correlation between the two activities. Electrophoresis and thermal denaturation studies failed to detect structural differences among lines with different levels of DIP-A activity. No characteristic level of activity could be associated with any DIP-A allozyme. Mapping experiments revealed the presence of activity modifiers that are in tight linkage with the structural gene, as well as those that manifest their effects from a distance. The maximum genetic distance between a high-activity effect on DIP-A and the structural gene was determined to be 0.029 map unit. These results are in accordance with the prevalence of activity modifiers for various enzymes inDrosophila melanogaster.
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  • 98
    ISSN: 1573-4927
    Keywords: glutamine synthetase I ; genetic mapping ; allozymes ; null alleles ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Recombinational and deletion mapping of electrophoretic variants of the glutamine synthetase I isozyme (GSI) inDrosophila melanogaster locates the gene in the 21B region on the second chromosome. We have conducted a genetic analysis of the region extending cytologically from 21A to 21B4-6. Recessive lethal mutations were generated by ethyl methanesulfonate (EMS) and ethyl nitrosourea (ENU) mutagenesis and by hybrid dysgenesis (HD). These lethals fall into seven functional groups, which were partially ordered by complementation with cytologically defined deficiencies of this region generated by hybrid dysgenesis. Two of the EMS- and two of the ENU-induced lethals fulfill biochemical criteria expected for null alleles of the GSI gene.
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  • 99
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    Biochemical genetics 26 (1988), S. 783-803 
    ISSN: 1573-4927
    Keywords: Drosophila ; dipeptidase activities ; genetic variation ; activity modifiers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract An examination ofDrosophila melanogaster from natural populations revealed genetic variation for dipeptidase-A (DIP-A) and dipeptidase-B (DIP-B) activities within sets of lines that differed from one another only in the second or the third chromosome. Analyses of diallel crosses indicate that both activities are inherited additively, and coordinate control of expression is suggested by the significant positive correlation between the two activities. Electrophoresis and thermal denaturation studies failed to detect structural differences among lines with different levels of DIP-A activity. No characteristic level of activity could be associated with any DIP-A allozyme. Mapping experiments revealed the presence of activity modifiers that are in tight linkage with the structural gene, as well as those that manifest their effects from a distance. The maximum genetic distance between a high-activity effect on DIP-A and the structural gene was determined to be 0.029 map unit. These results are in accordance with the prevalence of activity modifiers for various enzymes inDrosophila melanogaster.
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  • 100
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    Biochemical genetics 26 (1988), S. 527-541 
    ISSN: 1573-4927
    Keywords: Drosophila ; glue proteins ; glycosylation ; Chromosomal linkage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Larval glue protein fractions ofDrosophila nasuta nasuta were analyzed by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. Seven major and at least four minor glue protein fractions were recognized. Six of the major fractions are glycosylated. They migrate as three prominent doublets (〉100, 43, and 30/28 kd). The synthesis of traceable amounts of these major fractions begins already during the second as well as during the early stages of the third larval instar. The 43-kd and the 30/28-kd fractions are coded by X-chromosomal genes. They are probably clustered within the huge puff of division 10, which is the most prominent X-chromosomal puff in the polytene chromosomes of the third larval instar. Complex posttranslational modification of all but one major glue protein fraction (14 kd) leads to the formation of about 15 different protein fractions in the final glue product. The amount of glue protein produced byD. n. nasuta larvae (in relation to the total saliva proteins) is nearly twice the amount produced byD. melanogaster larvae (ca. 55 and 32%, respectively).
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