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  • Bone
  • Drosophila
  • Springer  (10)
  • Blackwell Publishing Ltd
  • International Union of Crystallography
  • Springer Nature
  • 2020-2022
  • 1975-1979  (10)
  • 1976  (10)
Collection
Keywords
Publisher
  • Springer  (10)
  • Blackwell Publishing Ltd
  • International Union of Crystallography
  • Springer Nature
Years
  • 2020-2022
  • 1975-1979  (10)
Year
  • 1
    Electronic Resource
    Electronic Resource
    The development of ommatidial patterning in metamorphosed eye imaginal discs implants ofDrosophila melanogaster (1976)
    Springer
    Development genes and evolution 179 (1976), S. 373-392 
    Details
    ISSN: 1432-041X
    Keywords: Compound Eye ; Development ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The development of the rhabdomeric pattern in the compound eye ofDrosophila has been studied using combined transplantation and electron microscope techniques. In a first series of experiments eye imaginal discs of increasing age were implanted into larvae ready to pupate, thus losing variable amounts of the normal time for development. A sequence of differentiative abilities was found in the metamorphosed test pieces. As far as the photoreceptor cells are concerned, the most prominent steps of this sequence are: ability to form groups with other similar elements, anatomical polarization of microvilli, establishment of the rhabdomeric pattern and formation of an equator line. The stability of determination of the equator line was tested in a second experimental series. Fragment of different topographical origin within the mature eye anlage were brought to metamorphosis by implantation into larvae ready to pupate. It was found that an equator line differentiates only in those pieces which according to the published anlage maps contain the prospective equator region prior to metamorphosis. The mitotic abilities of implanted eye imaginal discs were investigated by means of “in vitro”3H-thymidine pulse-labelling and light microscope autoradiography of the differentiated test pieces. During the third larval stage the eye anlage is traversed by two consecutive mitotic waves, each one of them producing different categories of receptor cells. The first, anterior wave predominantly produces cells oriented toward the poles of the eye within the ommatidia, while the second, posterior wave gives rise to elements exclusively in an equatorial position. The dynamics of this proliferation are discussed in relation to the findings in the implantation experiments. Silver-grain counts support the possibility that at least two successive cell divisions occur in the eye anlage between labeling with tritiated thymidine and beginning of morphological differentiation. The relevance of this finding for the understanding of the concept of acquisition of competence is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848244
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  • 2
    Electronic Resource
    Electronic Resource
    Entwicklungsgenetische Untersuchungen an Gynandern vonDrosophila melanogaster (1976)
    Springer
    Development genes and evolution 179 (1976), S. 349-372 
    Details
    ISSN: 1432-041X
    Keywords: Insect Development ; Genetic Mosaics ; Fate Maps ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Gynandromorphs with female XX-and male XO-areas result from the loss of an unstable ring-X-chromosome in the early cleavage mitoses of ring/rod-X-chromosome heterozygotes. The phenotypes of the recessive alleles on the rod-X-chromosome are expressed in the XO-areas. 377 larval gynandromorphs of the genotypeR(1)2, In(1)w vC /y w sn3Iz50e mal were examined and scored for the phenotypes of 13 paired and 10 unpaired structures (Table 2, Fig. 2). This was possible mainly by the cell-autonomous expression of aldehyde oxidase activity in soft tissues and by the comparison of the distribution of enzyme activity in wildtype and gynander larvae. The distances between pairs of structures were calculated in sturt-units (Tables 3 and 4). A morphogenetic fate map with the presumptive areas of larval structures was constructed (Fig. 3). The relative positions of the structures agree well with Poulson's fate map (Fig. 4). In addition, the distribution of phenotypes was scored in 380 adult gynandromorphs Table (5). The fate map (Fig. 5) which was constructed from these data is very similar to the fate map of larval structures. This similarity becomes even more pronounced if fate maps are constructed which contain only structures analogous in larva and imago (Table 6, Fig. 6). Therefore an attempt was made to set up an integrated morphogenetic fate map containing the presumptive areas of both larval and imaginal structures (Fig. 7). The possibilities of further blastoderm mapping are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848243
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  • 3
    Electronic Resource
    Electronic Resource
    The ommochrome biosynthetic pathway in Drosophila melanogaster: The head particulate phenoxazinone synthase and the developmental onset of xanthommatin synthesis (1976)
    Springer
    Biochemical genetics 14 (1976), S. 1077-1090 
    Details
    ISSN: 1573-4927
    Keywords: xanthommatin synthesis ; phenoxazinone synthase ; eye pigmentation ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Particulate fractions from the heads of Drosophila melanogaster catalyze the conversion of o-aminophenols to phenoxazinones. This particulate enzyme is stimulated by Mn2+. It has a number of features which distinguish it clearly from the Mn2+-dependent activity found in the soluble fraction. The particulate enzyme has a characteristic developmental pattern, showing a marked increase in activity at about the time of onset of xanthommatin synthesis. In addition, it is much reduced in activity in a number of xanthommatin-deficient mutants (v, cn, st, cd, and w). We believe that the head particulate enzyme is involved in xanthommatin biosynthesis and that the developmental onset of synthesis of this pigment is brought about by the synthesis or activation of this enzyme.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00485139
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  • 4
    Electronic Resource
    Electronic Resource
    Genetic control of soluble NDA-dependent sorbitol dehydrogenase in Drosophila melanogaster (1976)
    Springer
    Biochemical genetics 14 (1976), S. 1019-1039 
    Details
    ISSN: 1573-4927
    Keywords: sorbitol dehydrogenases ; polyols ; Drosophila ; spermatogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Experiments utilizing standard techniques of cell fractionation and disc electrophoresis have revealed the presence of three distinctly different enzymes which catalyze the oxidation of d-sorbitol in crude extracts of Drosophila melanogaster adults. These include (1) a soluble NAD-dependent sorbitol dehydrogenase (NAD-SoDHs), (2) a mitochondrial NAD-dependent sorbitol dehydrogenase (NAD-SoDHm), and (3) a soluble NADP-dependent sorbitol dehydrogenase (NADP-SoDH). The structural gene for NAD-SoDHs has been mapped to a locus between 65.3 and 65.6 on the third chromosome by means of an electrophoretic variant and a low-activity allele. Through the use of segmental aneuploidy, this gene has been localized to the region limited by salivary bands 91B–93F. Because mutants which alter either the activity or electrophoretic mobility of the soluble NAD-dependent enzyme have no significant measurable effect on the mitochondrial or NADP-dependent forms, it is suggested that the enzymes in this system are coded for autonomously by different genes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00485134
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  • 5
    Electronic Resource
    Electronic Resource
    Evidence for the adaptive significance of enzyme activity levels: Interspecific variation in α-GPDH and ADH in Drosophila (1976)
    Springer
    Biochemical genetics 14 (1976), S. 347-355 
    Details
    ISSN: 1573-4927
    Keywords: Drosophila ; enzyme activity variation ; α-glycerophosphate dehydrogenase ; alcohol dehydrogenase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The activity levels of alcohol dehydrogenase and α-glycerophosphate dehydrogenase were compared among nine species of Drosophila representing three phylogenetic groups. For any given life stage, interspecific variability in activity level was much greater for ADH than for α-GPDH. Patterns of ontogenetic expression of enzyme activity were also much more variable among species for ADH than for α-GPDH. These results are consistent with the interpretation that α-GPDH is involved with a relatively uniform adaptive function among species, whereas ADH levels may reflect variable adaptive capabilities. There is a significant correlation between ADH activities and survivorship on alcohol-treated media for these nine species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00484773
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  • 6
    Electronic Resource
    Electronic Resource
    Scanning electron microscopy of bone cells in culture (1976)
    Springer
    Cell & tissue research 166 (1976), S. 65-70 
    Details
    ISSN: 1432-0878
    Keywords: Collagen ; Bone ; Cell culture ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Embryonic and young rat bone cells have been grown in culture and examined in the scanning electron microscope (SEM). Compared with cells fixed in situ and taken directly from the animal, the cultured osteoblastic cells were smoother, flatter and more extensive and showed tighter intercellular contacts. Some matrix is formed in culture and undergoes at least partial mineralization as judged by the accumulation of Ca and P measured by energy dispersive x-ray analysis. Findings concerning the morphology of the collagen arrangement were indecisive. Some superficial cells, free of surrounding matrix, resembled osteocytes in normal in vivo bone. This may indicate that a proportion of the extracellular matrix produced by the cultured cells failed to polymerise into recognizable bone matrix, and that osteocytic morphology is not dependent upon the physical characteristics of the bone matrix.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00215125
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  • 7
    Electronic Resource
    Electronic Resource
    Effect of calcium depletion and subsequent repletion on parathyroids, parafollicular (C) cells and bone in the growing pig (1976)
    Springer
    Cell & tissue research 168 (1976), S. 373-384 
    Details
    ISSN: 1432-0878
    Keywords: Calcium ; Bone ; Parathyroid ; Parafollicular cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the chief cells of the parathyroid gland and thyroid parafollicular (C) cells and the morphology of bone in calcium depletion and subsequent repletion were examined in young growing pigs. A low calcium diet resulted in osteopenia, increased removal of the cartilaginous core, osteoclasia and osteocytic osteolysis. Subsequent repletion quickly returned bone to normal. In pigs fed the low calcium diet, there was a marked depletion of secretory granules but a striking increase in the number of microtubules in chief cells. Increasing the calcium content of the diet to normal quickly returned the ultrastructural appearance of chief cells to apparent normal. In the initial response to calcium repletion, chief cells exhibited large number of lysosomes and occasionally prominent paracrystalloid bodies. Electron microscopic examination of parafollicular (C) cells of the thyroid gland failed to reveal differences in ultrastructure between test and control pigs. These findings support the view that bone resorption following calcium deficiency may be the result of a secondary hyperparathyroidism rather than of calcium deficiency per se.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00215314
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  • 8
    Electronic Resource
    Electronic Resource
    Experimental study of changes in osteoblastic shape induced by calcitonin and parathyroid extract in an organ culture system (1976)
    Springer
    Cell & tissue research 169 (1976), S. 449-465 
    Details
    ISSN: 1432-0878
    Keywords: Bone ; Osteoblasts ; Cell surface ; Cell shape ; Calcitonin ; Parathyroid extract ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neonate rat endocranial osteoblasts were cultured on their bone surfaces in control medium (CC) or medium to which either parathyroid extract (PTE) or calcitonin (CT) had been added for 2, 4, 8 or 24 h. Some were cultured for 24 h in CC, then for 2, 4, 8 or 24 h in either CT or PTE medium; or for 24 h in PTE, then for 2, 4, 8 or 24 h in either CC or CT; or 24 h in CT and 2, 4, 8 or 24 h in CC. The dorsal ruffling of the cells in CC was found to be suppressed by later culturing with PTE and the disoriented cells reorganized to form arrays of parallel cells. The effects of PTE were also reversed by CC or CT: the osteoblasts in the second culture (CC) lost elongation and order, and proceeded through a proliferative phase before exhibiting the ruffling form similar to a single CC 24 h culture. PTE-cultured osteoblasts showed an increase in cell overlap and contact so that a more competent barrier was formed separating the bone from the medium. In control or CT medium, however, intercellular gaps were greater than in vivo.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218146
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  • 9
    Electronic Resource
    Electronic Resource
    Selection for geotaxis inDrosophila melanogaster: Heritability, degree of dominance and correlated responses to selection (1976)
    Springer
    Behavior genetics 6 (1976), S. 71-86 
    Details
    ISSN: 1573-3297
    Keywords: Drosophila ; geotaxis ; selection ; heritability ; correlated responses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Selection for geotaxis was carried out with flies from a natural population ofDrosophila melanogaster; geotactic behavior was measured by means of a Hirsch classification maze. The population was initially almost neutral to gravity, and it responded to both positive (downward) and negative (upward) selection with a realized heritability of about 0.13. Stabilizing selection toward neutral gravity was carried out simultaneously. At generations 6, 9, and 10, all possible hybrid crosses between pairs of the selected populations were generated and tested. The geotactic scores of hybrids in generations 6 and 9 were not significantly different from the midparent values, while the scores of hybrids in generation 10 deviated significantly from the midparent values in the direction of positive geotaxis. The frequencies of polymorphic inversions declined in every population during selection, but the population under neutral selection seemed to maintain a higher chromosomal polymorphism than those under positive or negative selection. There was no significant depression of productivity, measured as number of progeny, in any population during nine generations of selection.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01065679
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  • 10
    Electronic Resource
    Electronic Resource
    The genetic basis of receptivity of yellow mutantDrosophila melanogaster females (1976)
    Springer
    Behavior genetics 6 (1976), S. 141-143 
    Details
    ISSN: 1573-3297
    Keywords: Drosophila ; yellow mutant ; receptivity ; chromosome substitution ; backcrossing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Yellow mutant females ofDrosophila melanogaster are more receptive to yellow males than are wild-type females. By chromosomal substitution, this enhanced receptivity has been localized to the X chromosome. repeated backcrossing between a yellow and a wild-type inbred line, with the yellow locus maintained segregating, allows the conclusion that the yellow locus itself is responsible for the enhanced female receptivity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01067144
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