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  • Drosophila  (147)
  • Calcification
  • Springer  (188)
  • MDPI Publishing
  • 2000-2004  (31)
  • 1980-1984  (139)
  • 1965-1969  (18)
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  • 1
    Electronic Resource
    Electronic Resource
    Behavioural induction in Drosophila: timing and specificity (2000)
    Springer
    Entomologia experimentalis et applicata 94 (2000), S. 159-171 
    Details
    ISSN: 1570-7458
    Keywords: Drosophila ; induction ; habituation ; associative learning ; T-maze olfactometer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Experiments reported in this paper investigate the properties of a change in the responsiveness of adult Drosophila melanogaster induced by exposure to different rearing media. This effect has previously been described as habituation or associative learning. Exposure to food medium containing 0.08% menthol induced a positive response to menthol odour in a T-maze olfactometer. A brief (one hour) exposure to mentholic food just before testing was sufficient to induce a change in responsiveness. The effect did not persist through periods of more than an hour of separation from mentholic medium. Effects induced by exposure to a single compound were not specific to that compound alone. Menthol-reared flies (MRFs) differed from plain reared flies (PRFs) in their responsiveness to the odours of benzaldehyde and ethyl acetate, as well as menthol, and exposure to ethyl acetate induced a change in response to menthol odour. That there was an induced positive response to menthol in MRFs suggests that conventional habituation is insufficient to explain the induced change in responsiveness, but the generalised nature of this behavioural induction in MRFs is hard to explain in terms of associative learning. The mechanism underlying the induction remains elusive.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003998715018
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  • 2
    Electronic Resource
    Electronic Resource
    Lack of Evolutionary Divergence in Courtship Songs of Drosophila pseudoobscura Subspecies (2000)
    Springer
    Journal of insect behavior 13 (2000), S. 255-262 
    Details
    ISSN: 1572-8889
    Keywords: courtship song ; wingbeat ; sexual isolation ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007744416116
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  • 3
    Electronic Resource
    Electronic Resource
    Copulatory Courtship in Drosophila birchii and D. serrata, Species Recognition and Sexual Selection (2000)
    Springer
    Journal of insect behavior 13 (2000), S. 361-373 
    Details
    ISSN: 1572-8889
    Keywords: Drosophila ; copulatory courtship ; mate choice ; cryptic female choice
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Two endemic Australian Drosophila species, D. birchii and D. serrata, have a copulatory courtship, i.e., the males court the female mainly during copulation. In the present study we found the males of both species to mount their prospective mating partners selectively, exhibiting both sex and species recognition. The males began to sing after mounting the female, and they often exhibited also postcopulatory displays typical to copulatory courtship. D. birchii and D. serrata females discriminated against males which did not sing during mounting/copulation, which suggests that the females utilize cryptic female choice. Our findings raise the question of how widespread a phenomenon cryptic female choice is in Drosophila species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007710218609
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  • 4
    Electronic Resource
    Electronic Resource
    Patterning defects in the primary axonal scaffolds caused by the mutations of the extradenticle and homothorax genes in the embryonic Drosophila brain (2000)
    Springer
    Development genes and evolution 210 (2000), S. 289-299 
    Details
    ISSN: 1432-041X
    Keywords: Key words Brain development ; Axonal scaffold ; Extradenticle ; Homothorax ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  During early brain development in Drosophila a highly stereotyped pattern of axonal scaffolds evolves by precise pioneering and selective fasciculation of neural fibers in the newly formed brain neuromeres. Using an axonal marker, Fasciclin II, we show that the activities of the extradenticle (exd) and homothorax (hth) genes are essential to this axonal patterning in the embryonic brain. Both genes are expressed in the developing brain neurons, including many of the tract founder cluster cells. Consistent with their expression profiles, mutations of exd and hth strongly perturb the primary axonal scaffolds. Furthermore, we show that mutations of exd and hth result in profound patterning defects of the developing brain at the molecular level including stimulation of the orthodenticle gene and suppression of the empty spiracles and cervical homeotic genes. In addition, expression of a Drosophila Pax6 gene, eyeless, is significantly suppressed in the mutants except for the most anterior region. These results reveal that, in addition to their homeotic regulatory functions in trunk development, exd and hth have important roles in patterning the developing brain through coordinately regulating various nuclear regulatory genes, and imply molecular commonalities between the developmental mechanisms of the brain and trunk segments, which were conventionally considered to be largely independent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004270050316
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  • 5
    Electronic Resource
    Electronic Resource
    Analysis of a swallow homologue from Drosophila pseudoobscura (2000)
    Springer
    Development genes and evolution 210 (2000), S. 157-161 
    Details
    ISSN: 1432-041X
    Keywords: Key words Swallow ; bicoid ; Drosophila ; mRNA localization ; Oogenesis ; Embryogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  We analyzed a functional homologue of the swallow gene from Drosophila pseudoobscura. The swallow gene of D. melanogaster plays an essential role in localizing bicoid mRNA in oocytes, and swallow mutant embryos show anterior pattern defects that result from the lack of localization of the bicoid morphogen. The pseudoobscura homologue rescues the function of swallow mutants when introduced into the genome of D. melanogaster, and its expression is similar to that of the melanogaster gene. The predicted pseudoobscura and melanogaster proteins are 49% identical and 69% conserved. The coiled-coil domain previously identified in the melanogaster swallow protein is strongly conserved in the pseudoobscura homologue, but the weak similarity of the melanogaster swallow protein to the RNP class of RNA-binding proteins is not conserved in the pseudoobscura homologue. These and other observations suggest a structural role for swallow in localizing bicoid mRNA, perhaps as part of the egg cytoskeleton.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004270050023
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  • 6
    Electronic Resource
    Electronic Resource
    Changes in cell shape in the ventral neuroectoderm of Drosophila melanogaster depend on the activity of the achaete-scute complex genes (2000)
    Springer
    Development genes and evolution 210 (2000), S. 190-199 
    Details
    ISSN: 1432-041X
    Keywords: Key words Ventral neuroectoderm ; Cell shape ; Achaete-scute complex ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  In the embryonic ventral neuroectoderm of Drosophila melanogaster the proneural genes achaete, scute, and lethal of scute are expressed in clusters of cells from which the neuroblasts delaminate in a stereotyped orthogonal array. Analyses of the ventral neuroectoderm before and during delamination of the first two populations of neuroblasts show that cells in all regions of proneural gene activity change their form prior to delamination. Furthermore, the form changes in the neuroectodermal cells of embryos lacking the achaete-scute complex, of embryos mutant for the neurogenic gene Delta, and of embryos overexpressing l’sc suggest that these genes are responsible for most of the morphological alterations observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004270050303
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  • 7
    Electronic Resource
    Electronic Resource
    Coexistence of drosophilid flies: Aggregation, patch size diversity and parasitism (2000)
    Springer
    Ecological research 15 (2000), S. 93-100 
    Details
    ISSN: 1440-1703
    Keywords: aggregation ; coexistence ; Drosophila ; parasitism ; patch size
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: We carried out field experiments to investigate the coexistence of Drosophila species in domestic and forest areas on the basis of the aggregation model. Three cosmopolitan species Drosophila simulans Sturtevant, Drosophila melanogaster Meigen and Drosophila immigrans Sturtevant, and a native species, Drosophila auraria Peng, emerged abundantly from banana placed at the domestic station, while Drosophila immigrans and five native species, Drosophila lutescens Okada, Drosophila rufa Kikkawa and Peng, Drosophila bizonata Kikkawa and Peng, Drosophila sternopleuralis Okada and Kurokawa and Scaptodrosophila coracina (Kikkawa and Peng), were abundant at the forest station. The present analysis suggests that their coexistence was facilitated by the aggregation mechanism. In the cosmopolitan species, the density of individuals that emerged from patches increased with the increase of patch size, but the relationship between fly density and patch size was not clear in the native species. This difference in distribution patterns between the cosmopolitan and native species is likely to be due to the difference in the female visiting behavior. In the present analysis, however, it was not clear whether patch size diversity facilitated their coexistence or not. The effect of patch size diversity may have been masked, because the effect of aggregation was more prominent. The rate of parasitism by wasps was high in October at the domestic station, and in May and June at the forest station. The present result suggests that the rate of parasitism was density-dependent, at least at the domestic station, and therefore parasitism facilitates the coexistence of drosophilid species in domestic areas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1440-1703.2000.00328.x
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  • 8
    Electronic Resource
    Electronic Resource
    Identification ofDrosophila mutant with memory defects after acquisition of conditioned reflex suppression of courtship (2000)
    Springer
    Neuroscience and behavioral physiology 30 (2000), S. 307-313 
    Details
    ISSN: 1573-899X
    Keywords: Memory ; suppression of courting ; Drosophila ; mutants ; P insertion mutagenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Four lines were selected from a collection of 33 lines prepared by P insertion mutagenesis using a single-copy P-element system; the males of these four lines showed memory defects after acquisition of conditioned reflex suppression of courting. In two lines (P171 and P95), the dynamics of retention of the conditioned reflex in the repeated impregnated-female courting test were similar to those of known short-term memory mutantsdnc andrut. In line P153, the dynamics were more reminiscent of the memory dynamics in a known medium-term memory mutant,amn. In line P124, the learning index was insignificant immediately after training was completed, which may indicate that this line was unable to acquire conditioned reflex suppression of courting. Determination of the positions of the P elements (P171: 48A-B; P153: 49B-C; P124; 67B–68A; P95: 77C-D) showed no correspondence with previously known mutations producing memory lesions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02471783
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  • 9
    Electronic Resource
    Electronic Resource
    Parental Imprinting in Drosophila (2000)
    Springer
    Genetica 109 (2000), S. 35-44 
    Details
    ISSN: 1573-6857
    Keywords: Drosophila ; heterochromatin ; imprinting ; parental effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Genetic imprinting is a form of epigenetic silencing. But with a twist. The twist is that while imprinting results in the silencing of genes, chromosome regions or entire chromosome sets, this silencing occurs only after transmission of the imprinted region by one sex of parent. Thus genetic imprinting reflects intertwined levels of epigenetic and developmental modulation of gene expression. Imprinting has been well documented and studied in Drosophila, however, these studies have remained largely unknown due to nothing more significant than differences in terminology. Imprinting in Drosophilais invariably associated with heterochromatin or regions with unusual chromatin structure. The imprint appears to spread from imprinted centers that reside within heterochromatin and these are, seemingly, the only regions that are normally imprinted in Drosophila. This is significant as it implies that while imprinting occurs in Drosophila, it is generally without phenotypic consequence. Hence the evolution of imprinting, at least in Drosophila, is unlikely to be driven by the function of specific imprinted genes. Thus, the study of imprinting in Drosophilahas the potential to illuminate the mechanism and biological function of imprinting, and challenge models based solely on imprinting of mammalian genes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026592318341
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  • 10
    Electronic Resource
    Electronic Resource
    Searching for a Common Centromeric Structural Motif: Drosophila Centromeric Satellite DNAs Show Propensity to form Telomeric-Like Unusual DNA Structures (2000)
    Springer
    Genetica 109 (2000), S. 71-75 
    Details
    ISSN: 1573-6857
    Keywords: centromere ; heterochromatin ; non B-DNA structures ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The molecular basis of centromere formation in a particular chromosomal region is not yet understood. In higher eukaryotes, no specific DNA sequence is required for the assembly of the kinetochore, but similar centromeric chromatins are formed on different centromere DNA sequences. Although epigenesis has been proposed as the main mechanism for centromere specification, DNA recognition must also play a role. Through the analysis of Drosophilacentromeric DNA sequences, we found that dodeca satellite and 18HT satellite are able to form unusual DNA structures similar to those formed by telomeric sequences. These findings suggest the existence of a common centromeric structural DNA motif which we feel merits further investigation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026546510127
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  • 11
    Electronic Resource
    Electronic Resource
    Genetic and biochemical analysis of brown eye mutation in Drosophila nasuta nasuta and Drosophila nasuta albomicans (2000)
    Springer
    Genetica 109 (2000), S. 235-243 
    Details
    ISSN: 1573-6857
    Keywords: Drosophila ; brown eye ; eye pigments ; fitness ; gene localization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract By analyzing the progeny of crosses involving brown eye mutants and the wild types in two members of Drosophila nasuta subgroup namely D. n. nasuta and D. n. albomicans we could show that the mutant gene is recessive, located in the chromosome 2 and the alleles of this gene are present at different loci. A study of fitness in the eye color mutants in comparison with the wild types revealed that D. n. nasuta mutant has higher viability at both 25 ± 1°C and ambient temperatures; while D. n. albomicans mutant has faster rate of development only at 25 ± 1°C. Quantitative analysis of eye pigments in the mutants revealed that there is biosynthesis of both pteridines and xanthommatins unlike in bw/bw of D. melanogaster, where only xanthommatins are synthesized. In both the species, the pteridine quantities in mutants are similar; whereas xanthommatin quantity in $$\user1{bw}_n \user1{/bw}_n$$ is 10 times higher than that of $$\user1{bw}_a \user1{/bw}_a$$ . Further, the F1 progeny of intraspecific crosses (wild type X mutant) are found to have high amounts of pteridine, even when compared with parental wild type.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017505400086
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  • 12
    Electronic Resource
    Electronic Resource
    Dnop56, a Drosophila gene homologous to the yeast nucleolar NOP56 gene (2000)
    Springer
    Genetica 109 (2000), S. 275-282 
    Details
    ISSN: 1573-6857
    Keywords: DmNop56 ; DsNop56 ; Drosophila ; molecular evolution ; snoRNPs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Small nucleolar RNAs (snoRNAs) are trans‐acting factors involved in maturation of rRNA and have been classified into Box C/D and Box H/ACA families. Most of the snoRNAs occur as ribonucleoprotein complexes with snoRNA‐associated proteins (snoRNPs). All Box C/D snoRNAs in yeast form complexes with Nop1p, Nop56p and Nop58p. Similarly, it has been reported that Box H/ACA‐containing snoRNAs form complexes with yeast Gar1p. Nop56p and Nop58p homologs have been described in several species. Here we report the isolation and molecular characterization of the Dnop56 genes from D. melanogaster and D. subobscura which show a very similar structure. Drosophila Nop56p proteins contain lysine‐rich regions at their carboxy‐terminus, and show a high degree of similarity to other Nop56p proteins from different organisms. Phylogenetic relationships among these proteins and other snoRNPs have been established.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017596312331
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  • 13
    Electronic Resource
    Electronic Resource
    Calmodulin-dependent and -independent apoptosis in cells of a Drosophila neuronal cell line (2000)
    Springer
    Apoptosis 5 (2000), S. 133-140 
    Details
    ISSN: 1573-675X
    Keywords: Apoptosis ; calmodulin ; caspases ; cell line ; Drosophila ; neuron
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract This study was undertaken to reveal apoptotic pathways in neurons using a Drosophila neuronal cell line derived from larval central nervous system. We could induce apoptotic cell death in the cells by a Ca2+ ionophore (A23187), a protein kinase inhibitor (H-7), an RNA synthesis inhibitor (actinomycin D) and a protein synthesis inhibitor (cycloheximide). All the apoptosis induced by each chemical required Ca2+ ions, although the origin of Ca2+ ions were different: apoptosis induced by A23187 was dependent on extracellular Ca2+ ions whereas those by the other three chemicals utilized intracellular Ca2+ ions. Furthermore, different reactions to W-7, a calmodulin inhibitor, were found: W-7 prevented the cell death by each of the three chemicals but not by A23187. Based on the results, we proposed that the apoptotic pathways are classified into two types in individual cells. One pathway induced by H-7, actinomycin D or cycloheximide is calmodulin-dependent (pathway H), and another induced by A23187 is calmodulin-independent (pathway A).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009676528805
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  • 14
    Electronic Resource
    Electronic Resource
    An episode of accelerated amino acid change in Drosophila esterase-6 associated with a change in physiological function (2000)
    Springer
    Genetica 110 (2000), S. 231-244 
    Details
    ISSN: 1573-6857
    Keywords: Drosophila ; , esterase-6 ; function ; sequence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In most lineages of the subgenus Sophophora esterase-6 is a homodimeric haemolymph protein. In the melanogaster subgroup of species it has become a monomer which is mainly expressed in the male sperm ejaculatory duct. Our analyses of esterase-6 sequences from three melanogaster subgroup species and two close relatives reveal a brief period of accelerated amino acid sequence change during the transition between the ancestral and derived states. In this period of 2–6Myr the ratio of replacement to silent site substitutions (0.51) is about three times higher than the values in other lineages of the phylogeny. There are about 50 more replacements in this period than would be predicted from the ratios of replacement to silent site substitutions found elsewhere in the phylogeny. Modelling on the known structure of a related acetylcholinesterase suggests that an unusually high proportion of the replacements in the transitional branch are non-conservative changes on the protein surface. Up to half the accelerated replacement rate can be accounted for by clusters of changes to the face of the molecule containing the opening of the active site gorge. This includes changes in and around regions homologous to peripheral substrate binding sites in acetylcholinesterase. There are also three changes in glycosylation status. One region predicted to lie on the protein surface which becomes markedly more hydrophilic is proposed to be the ancestral dimerisation site that is lost in the transitional branch.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1012727814167
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  • 15
    Electronic Resource
    Electronic Resource
    Impact of Multiple Insertions of two Retroelements, ZAM and Idefix at an Euchromatic Locus (2000)
    Springer
    Genetica 109 (2000), S. 53-59 
    Details
    ISSN: 1573-6857
    Keywords: chromatin structure ; Drosophila ; mutagenic effect ; retroelements ; white
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Transposable elements represent a large fraction of eukaryotic genomes and they are thought to play an important role in chromatin structure. ZAMand Idefixare two LTR-retrotransposons from Drosophila melanogastervery similar in structure to vertebrate retroviruses. In all the strains where their distribution has been studied, ZAMappears to be present exclusively in the intercalary heterochromatin while Idefixcopies are mainly found in the centromeric heterochromatin with very few copies in euchromatin. Their distribution varies in a specific strain called RevI in which the mobilization of ZAMand Idefixis highly induced. In this strain, 15 copies of ZAMand 30 copies of Idefixare found on the chromosomal arms in addition to their usual distribution. Amongst the loci where new copies are detected, a hotspot for their insertion has been detected at the whitelocus where up to four elements occurred within a 3-kb fragment at the 5′ end of this gene. This property of ZAMand Idefixto accumulate at a defined site provides an interesting paradigm to bring insight into the effect exerted by multiple insertions of transposable elements at an euchromatic locus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026534207401
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  • 16
    Electronic Resource
    Electronic Resource
    Variations of male cuticular hydrocarbons with geoclimatic variables: an adaptative mechanism in Drosophila melanogaster? (2000)
    Springer
    Genetica 110 (2000), S. 117-130 
    Details
    ISSN: 1573-6857
    Keywords: adaptation ; Drosophila ; hydrocarbons ; latitude ; longitude ; natural populations ; polymorphism ; temperaturey ; vapour pressure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract 7-tricosene (7T) and 7-pentacosene (7P) are the major components of cuticular hydrocarbons in Drosophila simulans and D. melanogaster males. A chemical study of 16 isofemale lines of D. melanogaster sampled at the first and eighth generations in laboratory conditions showed the stability of chromatographical profiles. Then a large scale study of male 7T/7P polymorphism was performed with 85 populations of D. melanogaster and 29 of D. simulans collected all over the world. There were significant correlations of the values of the balanced ratio (7T − 7P)/(7T + 7P) with geo-climatic parameters, such as latitude, longitude, mean temperature, temperature range and vapour pressure. Parallel variations were also reported for the homologous linear alkanes (23 and 25 Carbon atoms) but not for the longer branched alkanes (27 and 29 Carbon atoms). No correlation was significant for the D. simulans populations studied. In this species a similar polymorphism of 7T/7P was found but restricted to a few populations from West Equatorial Africa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017987220814
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  • 17
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    Genetic variance in temperature dependent adult size deriving from physiological genetic variation at temperature boundaries (2000)
    Springer
    Genetica 110 (2000), S. 195-207 
    Details
    ISSN: 1573-6857
    Keywords: biophysics ; body size ; Drosophila ; ectotherm ; genetic variance ; stress ; temperature extreme
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An increase in genetic variation in body size has often been observed under stress; an increase in dominance variance and interaction variance as well as in additive genetic variance has been reported. The increase in genetic variation must be caused by physiological mechanisms that are specific to adverse environments. A model is proposed to explain the occurrence of an increase in genetic variation in body size in Drosophila at extreme temperatures. The model has parameters specific to the low- and high-temperature regions of the viable range. Additive genetic variation in the boundary temperatures leads to a marked increase in additive genetic variation in development rate and body size at extreme temperatures. Additive genetic variation in the temperature sensitivity in the low- and high-temperature regions adds non-additive genetic variation. Development rate shows patterns in additive genetic variation that differ from the patterns of genetic variation in body size; therefore, the genetic correlation between development rate and body size changes sign repeatedly as a function of temperature. The existence of dominance in the genetic variation in the boundary temperatures or in the low- and high-temperature sensitivities leads to a higher total genetic variance due to higher dominance and interaction variance, for both development rate and body size.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017974618477
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  • 18
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    Distinct requirements for the AP-3 adaptor complex in pigment granule and synaptic vesicle biogenesis in Drosophila melanogaster (2000)
    Springer
    Molecular genetics and genomics 263 (2000), S. 1003-1014 
    Details
    ISSN: 1617-4623
    Keywords: Key words AP-3 ; Biogenesis ; Pigment granule ; Synaptic vesicle ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The AP-3 adaptor protein complex has been implicated in the biogenesis of lysosome-related organelles, such as pigment granules/melanosomes, and synaptic vesicles. Here we compare the relative importance of AP-3 in the biogenesis of these organelles in Drosophila melanogaster. We report that the Drosophila pigmentation mutants orange and ruby carry genetic lesions in the σ3 and β3-adaptin subunits of the AP-3 complex, respectively. Electron microscopy reveals dramatic reductions in the numbers of electron-dense pigment granules in the eyes of these AP-3 mutants. Mutant flies also display greatly reduced levels of pigments housed in these granules. In contrast, electron microscopy of retinula cells reveals numerous synaptic vesicles in both AP-3 mutant and wild-type flies, while behavioral assays show apparently normal locomotor ability of AP-3 mutant larvae. Together, these results demonstrate that Drosophila AP-3 is critical for the biogenesis of pigment granules, but is apparently not essential for formation of a major population of synaptic vesicles in vivo.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00008688
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  • 19
    Electronic Resource
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    Control of Telomere Elongation and Telomeric Silencing in Drosophila Melanogaster (2000)
    Springer
    Genetica 109 (2000), S. 61-70 
    Details
    ISSN: 1573-6857
    Keywords: Drosophila ; heterochromatin ; telomere ; transcription ; transposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Chromosome length in Drosophilais maintained by the targeted transposition of two families of non-LTR retrotransposons, HeT-Aand TART. Although the rate of transposition to telomeres is sufficient to counterbalance loss from the chromosome ends due to incomplete DNA replication, transposition as a mechanism for elongating chromosome ends raises the possibility of damaged or deleted telomeres, because of its stochastic nature. Recent evidence suggests that HeT-Atransposition is controlled at the levels of transcription and reverse transcription. HeT-Atranscription is found primarily in mitotically active cells, and transcription of a w +reporter gene inserted into the 2L telomere increases when the homologous telomere is partially or completely deleted. The terminal HeT-Aarray may be important as a positive regulator of this activity in cis, and the subterminal satellite appears to be an important negative regulator in cis. A third chromosome modifier has been identified that increases the level of reverse transcriptase activity on a HeT-A RNA template and greatly increases the transposition of HeT-A. Thus, the host appears to play a role in transposition of these elements. Taken together, these results suggest that control of HeT-Atransposition is more complex than previously thought.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026548503320
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  • 20
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    Molecular organization of the Drosophila melanogaster Adh chromosomal region in D. replete and D. buzzatii, two distantly related species of the Drosophila subgenus (2000)
    Springer
    Chromosome research 8 (2000), S. 375-385 
    Details
    ISSN: 1573-6849
    Keywords: Adh ; Drosophila ; FISH ; genome evolution ; repleta group
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The molecular organization of a 1.944-Mb chromosomal region of Drosophila melanogaster around the Adh locus has been analyzed in two repleta group species: D. repleta and D. buzzatii. The extensive genetic and molecular information about this region in D. melanogaster makes it a prime choice for comparative studies of genomic organization among distantly related species. A set of 26 P1 phages from D. melanogaster were successfully hybridized using fluorescence in-situ hybridization (FISH) to the salivary gland chromosomes of both repleta group species. The results show that the Adh region is distributed in D. repleta and D. buzzatii over six distant sites of chromosome 3, homologous to chromosomal arm 2L of D. melanogaster (Muller's element B). This observation implies a density of 2.57 fixed breakpoints per Mb in the Adh region and suggests a considerable reorganization of this chromosomal element via the fixation of paracentric inversions. Nevertheless, breakpoint density in the Adh region is three times lower than that estimated for D. repleta chromosome 2, homologous to D. melanogaster 3R (Muller's element E). Differences in the rate of evolution among chromosomal elements are seemingly persistent in the Drosophila genus over long phylogenetic distances.
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    URL: http://dx.doi.org/10.1023/A:1009206702214
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    Distribution of the Transposable Element Minos in the Genus Drosophila (2000)
    Springer
    Genetica 108 (2000), S. 263-267 
    Details
    ISSN: 1573-6857
    Keywords: Drosophila ; horizontal transfer ; Minos ; Tc1-like ; Tc1-marinerfamily ; transposable elements ; transposon distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We analyzed 28 species of the genus Drosophilafor the presence of the Tc1-like transposable element Minosusing Southern blot hybridization under high stringency conditions. The Minostransposon was found in members of both the Drosophilaand the Sophophorasubgenus showing a distribution that is wider if compared to other well-studied Drosophilatransposons such as the Pelement, hoboand mariner. The presence of Minos-hybridizing sequences was discontinuous in the Sophophorasubgenus, especially in the melanogasterspecies group. Using the Polymerase Chain Reaction we amplified a portion corresponding to the putative Minostransposase from different Drosophilaspecies. Cloning and sequence analysis of randomly selected Minoscopies from D. mojavensisis, D. saltansand D. willistonisupports the idea that event(s) of horizontal transfer may have contributed to the spreading of this transposon in the Drosophilagenus.
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    URL: http://dx.doi.org/10.1023/A:1004185024017
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    Spatial differences in patterns of modification: selection on hairy in Drosophila melanogaster wings (2000)
    Springer
    Genetica 109 (2000), S. 169-181 
    Details
    ISSN: 1573-6857
    Keywords: artificial selection ; atavistic structures ; Drosophila ; pattern formation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Artificial selection was carried out for over 45 generations to enhance and suppress expression of the mutation hairy on the Drosophila melanogaster wing. Whole chromosome mapping of X‐linked and autosomal modifiers of sense organ number displayed regional differences in magnitude and direction of their effects. Regional specificity of modifier effects was also seen in some interchromosomal interactions. Scanning electron microscopy allowed precise measurement of sense organ size and position along the L3 longitudinal wing vein. Sense organ size varied in a predictable fashion along the proximal–distal axis, and the dorsal pattern differed from the ventral pattern. The high and low selection lines differed most in the proximal portion of the L3 vein. Extra sense organs in the High line were often associated with vein fragments at locations predicted from ancestral vein patterns. Thus, regional specificity of polygenic or quantitative trait locus modifier effects was identified in several different parts of the wing.
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    URL: http://dx.doi.org/10.1023/A:1017531404454
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    Genetic analysis of extended lifespan in Drosophila melanogaster III. On the relationship between artificially selected and wild stocks (2000)
    Springer
    Genetica 109 (2000), S. 245-253 
    Details
    ISSN: 1573-6857
    Keywords: artificial selection ; Drosophila ; lifespan ; mortality ; paraquat ; DDT ; recovery hypothesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Adult lifespans, age‐specific survival, age‐specific mortality, survival times on paraquat, and survival times on DDT were assayed in seven lines of Drosophila melanogaster, including two genetically heterogeneous wild lines recently collected from nature, and three inbred and recombinant inbred lines derived from an artificial selection experiment for increased lifespan. Survival on paraquat is positively correlated with adult lifespan. DDT resistance is uncorrelated with either paraquat resistance or lifespan. The wild lines are unexceptional with respect to average lifespan, paraquat resistance, age‐specific survivorship, and leveling off of mortality rates at advanced ages, but have high levels of DDT resistance. Cluster analysis groups the wild lines with three unselected laboratory stocks in one cluster, while two long‐lived elite recombinant inbred lines form a second cluster. Long‐lived laboratory‐adapted lines are quantitatively differentiated from the wild stocks, both with respect to average adult lifespans and resistance to an oxidizing agent. We reject the ‘recovery’ hypothesis, which proposes that Drosophila artificially selected for long life have phenotypes that merely recover the wild state.
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    URL: http://dx.doi.org/10.1023/A:1017569318401
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    Role of AWD/Nucleoside Diphosphate Kinase in Drosophila Development (2000)
    Springer
    Journal of bioenergetics and biomembranes 32 (2000), S. 293-300 
    Details
    ISSN: 1573-6881
    Keywords: abnormal wing discs ; lethal mutant ; Drosophila ; Killer-of-prune ; prune
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Physics
    Notes: Abstract The abnormal wing discs gene of Drosophila encodes a soluble protein with nucleosidediphosphate kinase activity. This enzymic activity is necessary for the biological function ofthe abnormal wing discs gene product. Complete loss of function, i.e., null, mutations causelethality after the larval stage. Most larval organs in such null mutant larvae appear to benormal, but the imaginal discs are small and incapable of normal differentiation.Killer-of-prune is a neomorphic mutation in the abnormal wing discs gene. It causes dominant lethalityin larvae that lack prune gene activity. The Killer-of-prune mutant protein may have alteredsubstrate specificity. Null mutant larvae have a low level of nucleoside diphosphate kinaseactivity. This suggests that there may be additional Drosophila genes that encode proteinswith nucleoside dipthosphate kinase activity. Candidate genes have been found in theDrosophila genome.
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    URL: http://dx.doi.org/10.1023/A:1005545214937
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    Common Mechanisms of Y Chromosome Evolution (2000)
    Springer
    Genetica 109 (2000), S. 105-111 
    Details
    ISSN: 1573-6857
    Keywords: Drosophila ; evolution ; heterochromatin ; Y chromosome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Y chromosome evolution is characterized by the expansion of genetic inertness along the Y chromosome and changes in the chromosome structure, especially the tendency of becoming heterochromatic. It is generally assumed that the sex chromosome pair has developed from a pair of homologues. In an evolutionary process the proto-Y-chromosome, with a very short differential segment, develops in its final stage into a completely heterochromatic and to a great extends genetically eroded Y chromosome. The constraints evolving the Y chromosome have been the objects of speculation since the discovery of sex chromosomes. Several models have been suggested. We use the exceptional situation of the in Drosophila mirandato analyze the molecular process in progress involved in Y chromosome evolution. We suggest that the first steps in the switch from a euchromatic proto-Y-chromosome into a completely heterochromatic Y chromosome are driven by the accumulation of transposable elements, especially retrotransposons inserted along the evolving nonrecombining part of the Y chromosome. In this evolutionary process trapping and accumulation of retrotransposons on the proto-Y-chromosome should lead to conformational changes that are responsible for successive silencing of euchromatic genes, both intact or already mutated ones and eventually transform functionally euchromatic domains into genetically inert heterochromatin. Accumulation of further mutations, deletions, and duplications followed by the evolution and expansion of tandem repetitive sequence motifs of high copy number (satellite sequences) together with a few vital genes for male fertility will then represent the final state of the degenerated Y chromosome.
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    URL: http://dx.doi.org/10.1023/A:1026584016524
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    Versatility of Conviction: Heterochromatin as Both a Repressor and an Activator of Transcription (2000)
    Springer
    Genetica 109 (2000), S. 19-24 
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    ISSN: 1573-6857
    Keywords: chromosomal proteins ; Drosophila ; heterochromatin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026544717126
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    Drosophila Telomeric Transgenes Provide Insights on Mechanisms of Gene Silencing (2000)
    Springer
    Genetica 109 (2000), S. 25-33 
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    ISSN: 1573-6857
    Keywords: chromatin ; Drosophila ; heterochromatin ; position effect variegation ; telomeres
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A significant fraction of most eukaryotic genomes is packaged into chromatin that is not permissive for gene expression. This silent chromatin is typically located near centromeres and telomeres and has fascinated scientists for more than 70 years, yet many questions remain unanswered. Part of the difficulties in studying silent chromatin at the molecular level is the repetitive nature of the DNA sequences in these regions. To overcome this problem, Drosophilastocks carrying in vitrodesigned transgenes inserted within silent chromatin have been generated. Molecular analysis of these transgenes has shed light on the nature of the chromatin structure within these regions and provided insights on the mechanisms of gene silencing. This review will focus on recent studies using telomeric transgenes. The results from these studies suggest that nuclear organization plays a role in gene silencing and that silencing is the result of a block early in the process of transcription initiation.
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    URL: http://dx.doi.org/10.1023/A:1026556705137
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    Isolation of True Rbp9 Null Alleles by Imprecise P Element Excisions (2000)
    Springer
    Molecules and cells 10 (2000), S. 61-64 
    Details
    ISSN: 0219-1032
    Keywords: Drosophila ; Imprecise Excision ; Null Allele ; P Element ; Rbp9
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The P element has been widely used as a mutagen because of its convenience in locating the site of mutagenesis. However, P element-induced mutations often result in varied mutant phenotypes, making it difficult to identify the null phenotype. Previously, three Rbp9 alleles were isolated using P element mutagenesis. Although the coding regions of Rbp9 were disrupted by P elements in all three cases, they showed different degrees of defects. In order to characterize the null phenotype of Rbp9, Rbp9 alleles with chromosomal deletions were created by inducing imprecise excisions of the P elements. All Rbp9 alleles generated from imprecise excisions showed the same mutant phenotype: female flies were sterile and cystocyte differentiation was blocked. This result reveals that the primary function of Rbp9 resides in the regulation of cystocyte differentiation. In addition, this result shows that a P element does not always completely inactivate gene activity, even when it is incorporated into the coding region.
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    URL: http://dx.doi.org/10.1007/s10059-000-0061-1
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    Effects of Polycomb Group Mutations on the Expression of Ultrabithorax in the Drosophila Visceral Mesoderm (2000)
    Springer
    Molecules and cells 10 (2000), S. 156-161 
    Details
    ISSN: 0219-1032
    Keywords: Drosophila ; Polycomb Group Genes ; Ultrabithorax ; Visceral Mesoderm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Polycomb group (PcG) genes encode repressors of many developmental regulatory genes including homeotic genes and are known to act by modifying chromatin structure through complex formation. We describe how Ultrabithorax (Ubx) expression is affected by the PcG mutants in the visceral mesoderm. Mutant embryos of the genes extra sex combs (esc), Polycomb (Pc), additional sex combs (Asx) and pleiohomeotic (pho) were examined. In each mutation, Ubx was ectopically expressed outside of their normal domains along the anterior-posterior axis in the visceral mesoderm, which is consistent with the effect of PcG proteins repressing the homeotic genes in other tissues. All of these four PcG mutations exhibit complete or partial lack of midgut constriction. However, two thirds of esc mutant embryos did not show Ubx expression in parasegment 7 (PS7). Even in the embryos showing ectopic Ubx expression, the level of Ubx expression in the PcG mutations was weaker than that in normal embryos. We suggest that in PcG mutations the ectopic Ubx expression is caused by lack of PcG repressor proteins, while the weaker or lack of Ubx expression is due to the repression of Ubx by Abd-B protein which is ectopically expressed in PcG mutations as well.
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    URL: http://dx.doi.org/10.1007/s10059-000-0156-8
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    Regulation of Mst57Dc Expression in Male Accessory Glands of Dorsophila melanogaster (2000)
    Springer
    Molecules and cells 10 (2000), S. 180-185 
    Details
    ISSN: 0219-1032
    Keywords: Drosophila ; Gene Expression ; JHRE ; Juvenile Hormone ; Male Accessory Gland ; Mst57Dc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mst57Dc has been isolated as a male accessory gland transcript of Drosophila melanogaster. Its product is a secretory protein, which is phosphorylated by protein kinase A. In the present study, the expression pattern of Mst57Dc was analyzed. It is preferentially expressed in but not restricted to the male accessory glands. Other than in the accessory glands, it is slightly expressed in other body parts, including the head and female body. In the accessory glands, a high level of expression was detected right after eclosion when the titer of juvenile hormone III (JHIII) reaches a peak. Its accumulation was increased by mating, which has been known to act via JH. In ap56f, a JH-deficient mutant, the level of Mst57Dc transcripts was about 60% of the wild type. Moreover a JH-responsive element like palindromic sequence and several sequence motifs were found in the 5′ and 3′ flanking regions of Mst57Dc. Taken together, JH is proposed as a regulator of Mst57Dc gene expression.
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    URL: http://dx.doi.org/10.1007/s10059-000-0180-8
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    Behavioral Characterization and Genetic Analysis of the Drosophila melanogaster Larval Response to Light as Revealed by a Novel Individual Assay (2000)
    Springer
    Behavior genetics 30 (2000), S. 59-69 
    Details
    ISSN: 1573-3297
    Keywords: Insect ; larval photobehavior ; locomotion ; Drosophila ; behavioral mutants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract A new assay was designed, named checker, that measures the individual response to light in the fruitfly Drosophila melanogaster larva. In this assay the Drosophila larva apparently modulates its pattern of locomotion when faced with a choice between a dark and lit environment by orienting its movement towards the dark environment. We show that, in this assay, a response to light can be measured as an increase in residence time in the dark versus the lit quadrant. Mutations that disrupt phototransduction in the adult Drosophila abolish the larval response to light, demonstrating that this larval visual function is similar to that of the adult fly. Similarly, no response to light was detected in strains where the larval visual system (photoreceptors and target area) was disrupted by a mutation in the homeobox containing gene sine oculis (so) gene. Ablation of photoreceptors by the targeted expression of the cell death gene hid under the control of the photoreceptor-specific transcription factor glass (gl) abolishes this response entirely. Finally, we demonstrate that this response to light can be mediated by rhodopsins other than the blue absorbing Rh1.
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    URL: http://dx.doi.org/10.1023/A:1002090627601
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    Adjacent chromosomal regions can evolve at very different rates: Evolution of theDrosophila 68C glue gene cluster (1984)
    Springer
    Journal of molecular evolution 20 (1984), S. 251-264 
    Details
    ISSN: 1432-1432
    Keywords: Drosophila ; Genome evolution ; 68C Glue gene cluster ; Drosophila melanogaster species subgroup
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The 68C puff is a highly transcribed region of theDrosophila melanogaster salivary gland polytene chromosomes. Three different classes of messenger RNA originate in a 5000-bp region in the puff; each class is translated to one of the salivary gland glue proteins sgs-3, sgs-7, or sgs-8. These messenger RNA classes are coordinately controlled, with each RNA appearing in the third larval instar and disappearing at the time of puparium formation. Their disappearance is initiated by the action of the steroid hormone ecdysterone. In the work reported here, we studied evolution of this hormone-regulated gene cluster in themelanogaster species subgroup ofDrosophila. Genome blot hybridization experiments showed that five other species of this subgroup have DNA sequences that hybridize toD. melanogaster 68C sequences, and that these sequences are divided into a highly conserved region, which does not contain the glue genes, and an extraordinarily diverged region, which does. Molecular cloning of this DNA fromD. simulans, D. erecta, D. yakuba, andD. teissieri confirmed the division of the region into a slowly and a rapidly evolving protion, and also showed that the rapidly evolving region of each species codes for third instar larval salivary gland RNAs homologous to theD. melanogaster glue mRNAs. The highly conserved region is at least 13,000 bp long, and is not known to code for any RNAs.
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    Mutations affecting the pattern of the larval cuticle inDrosophila melanogaster (1984)
    Springer
    Development genes and evolution 193 (1984), S. 267-282 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Larval cuticle ; Pattern formation ; Embryonic lethal mutations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In a search for embryonic lethal mutants on the second chromosome ofDrosophila melanogaster, 5764 balanced lines isogenic for an ethyl methane sulfonate (EMS)-treatedcn bw sp chromosome were established. Of these lines, 4217 carried one or more newly induced lethal mutations corresponding to a total of 7600 lethal hits. Eggs were collected from lethal-bearing lines and unhatched embryos from the lines in which 25% or more of the embryos did not hatch (2843 lines) were dechorionated, fixed, cleared and scored under the compound microscope for abnormalities of the larval cuticle. A total of 272 mutants were isolated with phenotypes unequivocally distinguishable from wild-type embryos on the basis of the cuticular pattern. In complementation tests performed between mutants with similar phenotype, 48 loci were identified by more than one allele, the average being 5.4 alleles per locus. Complementation of all other mutants was shown by 13 mutants. Members of the complementation groups were mapped by recombination analysis. No clustering of loci with similar phenotypes was apparent. From the distribution of the allele frequencies and the rate of discovery of new loci, it was estimated that the 61 loci represent the majority of embryonic lethal loci on the second chromosome yielding phenotypes recognizable in the larval cuticle.
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    URL: http://dx.doi.org/10.1007/BF00848156
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    Isolation and characterization of temperature-sensitivelethal (2) giant larva alleles (1984)
    Springer
    Development genes and evolution 193 (1984), S. 90-97 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Temperature-sensitive ; Neoplasms ; Differentiation ; Imaginal discs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary EMS induced temperature-sensitivelethal (2) giant larva, 1(2)gl, alleles were isolated by screening against a knownl(2)gl allele. Analysis of the lethal phase of thel(2)gl ts-deficiency heterozygotes demonstrated: (1) the majority of thel(2)gl tslarvae survive to late third instar, (2) at 29°C the majority of thel(2)gl tslarvae failed to pupate and only rarely did they differentiate adult cuticular structures, (3) at 15°C the majority of the larvae pupated and frequently differentiated adult cuticular structures. Examination of the imaginal discs ofl(2)gl tslarvae reared at 29°C revealed the presence of morphologically abnormal wing, haltere and leg imaginal discs. No morphologically abnormal discs were found in thel(2)gl tslarvae reared at 15°C. Studies on both the histology and the developmental capacity of the morphologically normal and abnormall(2)gl tsdiscs were performed. The morphologically normal discs are histologically normal and produce a full complement of adult cuticular structures. However, the morphologically abnormal discs contained both regions that maintained the normal monolayer epithelium and regions that had lost the normal tissue architecture. The implants obtained when the morphologically abnormal discs are injected into metamorphosing larvae contained only a limited number of the normal complement of adult structures and usually only structures found in the ventral wing hinge region were recovered. In addition, the “metamorphosed” morphologically abnormal discs contained undifferentiated tissue that gave rise to transplantable neoplasms when cultured in adults. The results of the studies on the pathology of thel(2)gl tslarvae are discussed with respect to the role of thel(2)gl tsfunction during normal development, the autonomy of the neoplastic development of thel(2)gl tstissues, and similarities between neoplastic development inDrosophila and mammals.
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    Heterospecific combinations of germ cells and gonadal soma betweenDrosophila melanogaster, D. mauritiana andD. ananassae (1984)
    Springer
    Development genes and evolution 194 (1984), S. 99-106 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Pole cell transplantation ; Heterospecific combinations ; Gametogenesis ; Chorion morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We transplanted pole cells betweenDrosophila melanogaster, D. mauritiana andD. ananassae to investigate the ability of germ cells to develop in the gonad of a heterospecific host, and to study the interaction between somatic follicle cells and the cells of the germ line in producing the species-specific chorion. FemaleD. mauritiana germ cells in aD. melanogaster ovary produced functional eggs with normal development potential. The same is true for the reciprocal combination. FemaleD. ananassae pole cells in aD. melanogaster host only developed to a very early stage and degenerated afterwards. None of the interspecific combinations of male pole cells led to functional sperm. We could not determine at what stage the transplanted male pole cells were arrested. The cooperation of follicle cells and the oocyte-nurse cell complex in producing the chorion was studied using the germ-line-dependent mutationfs(1) K10 ofD. melanogaster, which causes fused respiratory appendages and an abnormal chorion morphology. Wild-type femaleD. mauritiana germ cells in a mutantfs(1) K10 D. melanogaster ovary led to the production of wild-type eggs withD. melanogaster-specific, short respiratory appendages. On the other hand,D. melanogaster fs(1) K10 germ cells in aD. mauritiana ovary induced the formation of eggs with mutant fused appendages which were, however, typicallyD. mauritiana in length. When.D. mauritiana pole cells developed in aD. melanogaster ovary, the chorion exhibited a new imprint pattern that differs from both species-specific patterns.
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    Isolation and characterization of temperature-sensitivelethal(2)giant larva alleles (1984)
    Springer
    Development genes and evolution 193 (1984), S. 98-107 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Neoplasms ; Promotion ; Regeneration ; Temperature-sensitive ; Imaginal discs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In this paper we present an analysis of the behavior ofl(2)gl tsimaginal wing discs during culture in adult hosts. Thel(2)gl tslarvae reared at 29° C contain two types of wing discs, those that are morphologically normal and those that are abnormal. When discs of both types are cultured in adult hosts at 29° C, the restrictive temperature, they give rise to transplantable neoplastic tissue. However, when the 29° C reared discs are cultured at 15° C, the permissive temperature, the morphologically normal discs maintain their morphology, but the morphologically abnormal discs give rise to neoplasms. Thel(2)gl tslarvae reared at 15° C contain only morphologically normal discs. When these discs are cultured in adult hosts at 29° C they give rise to neoplasms, however if the discs are cultured at 15° C they maintain their normal morphology. These results demonstrate: (1) that all wing imaginal discs obtained from 29° C rearedl(2)gl tslarvae are competent to undergo neoplastic development, (2) the morphologically abnormal discs obtained from the 29° C rearedl(2)gl tslarvae are committed to neoplastic development, (3) the neoplastic development of the morphologically normal discs is temperature dependent, (4) once the neoplastic development of thel(2)gl tsdiscs has been initiated the process is not readily reversible. In addition, the ability ofl(2)gl tswing discs to perform epimorphic regulation was tested by amputating morphologically normal permissively rearedl(2)gl tswing discs and culturing both fragiments at the permissive temperature. Fragments of control wild-type discs maintained their morphology during culture at the permissive temperature. However, both fragments of txel(2)gl tsdiscs became neoplastic. This result is discussed with respect to a possible role for thel(2)gl +function in epimorphic regulation and with respect to the phenomena of tumor promotion in vertebrates.
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    Changes in the distribution of gap junctions inDrosophila melanogaster wing discs during the third larval and early pupal stages of development (1984)
    Springer
    Development genes and evolution 193 (1984), S. 187-196 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Gap junction ; Imaginal disc ; Pattern formation ; EM Stereology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Developmental changes in the distribution of gap junctions in early, mid and late third larval stage wing discs and in pupariation+6 h and pupariation+24 h stage wing discs fromDrosophila melanogaster were analyzed by quantitative electron microscopy. Gap junctions occur in all 12 intradisc regions examined in each of the five developmental stages. Their distribution is non-random and changes during development which suggests that they are developmentally regulated. The gap junctions are not static structures, rather they grow and regress during development. The changes tend to be gradual ones without sudden increases or decreases. Gap junctions continuously form and grow in size throughout the third larval stage and during the first 6 h following pupariation. Their surface density, number, percent of the lateral plasma membrane area, and absolute area as well as the lateral plasma membrane surface density all increase during this time. Between pupariation+ 6 h and pupariation+24 h all but one of these parameters decrease indicative of gap junctional breakdown. Gap junctions are most numerous and change least during development in the apical cell regions where intercellular contacts are close and stable. They change most in the basal cell regions where intercellular contacts tend to be looser and change during development. The most dramatic change is in the absolute area which increases by a factor of 23 between the early third larval stage and pupariation+24 h. At pupariation the rate of gap junction growth undergoes a transient increase before the phase of disassembly begins. Developmental changes in gap junction surface density are closely coupled with changes in the lateral plasma membrane surface density which suggests that these may be coregulated. Evidence from mutants suggests that when the number and density of gap junctions fail to increase in proportion to lateral plasma membrane growth, wing disc development will be abnormal. Our results support the idea that some minimum gap junction density is required for normal development and that this must increase as development proceeds. The results are consistent with the notion that gap junctions are involved in pattern formation and growth control and are discussed with respect to the acquisition of competence for metamorphosis, disc growth, disc morphogenesis and changes in the hormonal environment.
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    URL: http://dx.doi.org/10.1007/BF01260338
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    Mutations affecting the pattern of the larval cuticle inDrosophila melanogaster (1984)
    Springer
    Development genes and evolution 193 (1984), S. 296-307 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Larval cuticle ; Pattern formation ; Embryonic lethal mutations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In order to identify X-chromosomal genes required inDrosophila for early patterning and morphogenesis, we examined embryos hemizygous for EMS-induced lethal mutations to determine which of those mutations cause gross morphological defects. Embryos from 2711 lethal lines, corresponding to 3255 lethal point mutations were studied. Only 21% caused death during embryogenesis and of these, only one-sixth, or 3% of the total lethals, were associated with defects visible in the final cuticle pattern. Of the 114 point mutants causing visible cuticle defects, 76 could be assigned to 14 complementation groups. An additional 25 mutations mapping to regions of the X-chromosome not covered by male fertile duplications were assigned to six complementation groups based on similarities of map position and phenotype. Thirteen mutations could not be assigned to complementation groups. All mutations allowed normal development through the cellular blastoderm stage, the first defects associated with the earliest acting loci being observed shortly after the onset of gastrulation. The phenotypes of the various loci range from alterations in segment pattern or early morphogenetic movements to defects in final pigmentation and denticle morphology. Cuticle preparations were also examined for 63 deletions spanning in total 74% of the X-chromosome, as well as for 8 deletions and point mutations derived in saturation mutagenesis screens of the fourth chromosome (Hochman 1976). With the exception of defects in head morphology and defects in cuticle differentiation, none of the hemizygous deletions showed phenotypes other than those predicted by point mutations known to lie in those regions. No deletion caused new or unknown alterations in gastrulation, segmentation or cuticle pattern.These results suggest that the number of genes required zygotically for normal embryonic patterning is small and that most, if not all such loci, are represented by point mutations in our collection.
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    The role of the peripodial membrane of leg and wing imaginal discs ofDrosophila melanogaster during evagination and differentiation in vitro (1984)
    Springer
    Development genes and evolution 193 (1984), S. 180-186 
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    ISSN: 1432-041X
    Keywords: Drosophila ; Imaginal disc ; Morphogenesis ; Tissue culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The thin region of the peripodial membrane is confined to the area overlying the distal anlagen in thoracic discs. During the early stages of evagination the peripodial membrane is greatly stretched, but does not rupture. The appendage then evaginates through the stalk, probably by means of a contraction of the peripodial membrane. The cells of the peripodial membrane of leg and wing discs persist and differentiate sheets of trichomes characteristic of the ventral and lateral thorax. This is discussed in relation to imaginal disc fate maps.
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    TheUbx syndrome ofDrosophila: the prothoracic transformation (ppx) is independent ofbx, bxd andpbx (1984)
    Springer
    Development genes and evolution 193 (1984), S. 263-265 
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    ISSN: 1432-041X
    Keywords: Drosophila ; Biothorax complex ; Prothoracic transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary If, early in development, theUbx + gene is removed by mitotic recombination from cells of the meso-and metathoracic leg primordia, theseUbx − cells develop as in the posterior prothoracic leg. We show that this transformation, termedpostprothorax, is a discrete genetic function that is independent of other homeotic transformations such asbx, pbx orbxd, which also result from the inactivation of theUbx gene.
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    Mutations affecting the pattern of the larval cuticle inDrosophila melanogaster (1984)
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    Development genes and evolution 193 (1984), S. 283-295 
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    ISSN: 1432-041X
    Keywords: Drosophila ; Larval cuticle ; Pattern formation ; Embryonic lethal mutations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The present report describes the recovery and genetic characterization of mutant alleles at zygotic loci on the third chromosome ofDrosophila melanogaster which alter the morphology of the larval cuticle. We derived 12600 single lines from ethyl methane sulfonate (EMS)-treatedst e orrucuca chromosomes and assayed them for embryonic lethal mutations by estimating hatch rates of egg collections. About 7100 of these lines yielded at least a quarter of unhatched eggs and were then scored for embryonic phenotypes. Through microscopic examination of unhatched eggs 1772 lines corresponding to 24% of all lethal hits were classified as embryonic lethal. In 198 lines (2.7% of all lethal hits), mutant embryos showed distinct abnormalities of the larval cuticle. These embryonic visible mutants define 45 loci by complementation analysis. For 32 loci, more than one mutant allele was recovered, with an average of 5.8 alleles per locus. Complementation of all other mutants was shown by 13 mutants. The genes were localized on the genetic map by recombination analysis, as well as cytologically by complementation analysis with deficiencies. They appear to be randomly distributed along the chromosome. Allele frequencies and comparisons with deficiency phenotypes indicate that the 45 loci represent most, if not all, zygotic loci on the third chromosome, where lack of function recognizably affects the morphology of the larval cuticle.
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    Early neurogenesis in wild-typeDrosophila melanogaster (1984)
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    Development genes and evolution 193 (1984), S. 308-325 
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    ISSN: 1432-041X
    Keywords: Neurogenesis ; Pattern of neuroblasts ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This paper deals with morphological aspects of early neurogenesis inDrosophila, in particular with the segregation of neuroblasts from the neurogenic region of the ectoderm and the pattern formed by those wells within both the germ band and the procephalic lobe. The neurogenic ectoderm was found to contain neural precursors intermingled with epidermal precursors, extending from the midline up to the primordia of the tracheal tree along the germ band and laterodorsally in the procephalic lobe. Germ band neuroblasts segregate from the neurogenic ectoderm during a period of several hours according to characteristic spatial and temporal patterns. During the first half of the segregation process the pattern of germ band neuroblasts was found to be the same in different animals in both spatial arrangement and number of cells; this permitted the identification of individual neuroblasts from different embryos. Later in development several difficulties were encountered which precluded an exact description of the neuroblast pattern. The constitution of the neurogenic region is discussed in relation to the phenotype of mutants affecting neurogenesis.
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    The spatial arrangement of germ line cells in ovarian follicles of the mutantdicephalic inDrosophila melanogaster (1984)
    Springer
    Development genes and evolution 193 (1984), S. 388-393 
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    ISSN: 1432-041X
    Keywords: Drosophila ; Oogenesis ; Ring canals ; Oocyte determination ; Polarity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The pattern of intercellular connections between germ line cells has been studied in follicles of the mutantdicephalic (dic), which possess nurse cell clusters at both poles. Staining of follicles with a fluorescent rhodamine conjugate of phalloidin reveals ring canals and cell membranes and thus allows us to reconstruct the spatial organization of the follicle. Each germ line cell can be identified by the pattern of cell-cell connections which reflect the mitotic history of individual cells in the 16-cell cluster. The results indicate that in both wild-type anddicephalic cystocyte clusters one of the two cells with four ring canals normally becomes the pro-oocyte. However, in some follicles (dicephalic and wild-type) oocytes were found with fewer or more than four ring canals. Indic follicles, one or several nurse cells may become disconnected from the other cells during oocyte growth at stage 9–10. Such disconnected cells cannot later on empty their cytoplasm into the oocyte. This, in turn, might be of consequence for the determination of axial polarity of the embryo.
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    Cell interactions during the fusionin vitro ofDrosophila eye-antennal imaginal discs (1984)
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    Development genes and evolution 193 (1984), S. 406-413 
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    ISSN: 1432-041X
    Keywords: Drosophila ; Imaginal disc ; Morphogenesis ; Tissue culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The fusion of the eye-antennal discs during culturein vitro has been investigated, and the complex morphogenetic movements which occur during the formation of the head capsule of the insect are described. The initial contact between the eye anlagen is by means of cell processes spanning the gap between the two discs. Subsequently the two epithelia become firmly apposed, and then the integrity of the epithelium in the region of fusion breaks down, cells appearing to move to new positions in order to form an epithelium which unites the two discs. The epithelium eventually secretes a pattern of cuticular structures which is continuous between the derivatives of the two discs. Bristles on either side of the line of fusion are perfectly aligned, and structures such as the median ocellus, which are formed jointly by the cells of the two discs, differentiate normally. This is also found when left and right eye-antennal discs of different genotypes are placed side-by-side, indicating that processes of pattern regulation can occur in culture.
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    Co-isolation of proteolipids and calcium-phospholipid-phosphate complexes (1984)
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    Calcified tissue international 36 (1984), S. 214-218 
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    ISSN: 1432-0827
    Keywords: Proteolipid ; Calcium-phospholipid-phosphate complexes ; Calcification ; Hydroxyapatite ; Membranes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary This study demonstrates that calciumphospholipid-phosphate complexes (CPLX) and calcifiable proteolipid are associatedin vivo by establishing that they can be co-isolated from calcified bacteria. Both of these membrane constituents, which support apatite formationin vitro, have been isolated independently fromBacterionema matruchotii. However, isolation of proteolipid was preceded by demineralization in 2N formic acid, thereby dissociating bound Ca, whereas isolation of CPLX included sonication of calcified bacteria in 2:1:1.5 chloroform:methanol:Tris buffer, thereby dissociating any protein. Co-isolation is possible by demineralizing the calcified bacteria with 50 mM phthalic acid, pH 5.5, followed by extraction with 2:1 chloroform:methanol, and precipitation of crude phospholipid with acetone. CPLX and proteolipid are present in all Sephadex LH-20 chromatographic fractions of the crude phospholipid and of diethyl ether precipitates of the crude phospholipid. CPLXs contain protein:phospholipid:Ca:Pi but differ in relative composition from each other and from independently isolated CPLX. The Ca:phospholipid:Pi molar ratio of diethyl ether precipitable proteolipid-CPLX is most similar to previously published values for CPLX. The protein content of CPLX accounts for all of the proteolipid apoprotein in each Sephadex LH-20 fraction.
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    Systematic purification of free and matrix-bound phosphophoryns of bovine dentin: Presence of matrix-bound phosphophoryn as a distinct molecular entity (1984)
    Springer
    Calcified tissue international 36 (1984), S. 239-242 
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    ISSN: 1432-0827
    Keywords: Phosphoprotein ; Dentin ; Calcification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Free and matrix-bound phosphophoryns, both highly phosphorylated proteins in dentin, were prepared from EDTA extract and CNBr-digests of bovine dentin. The two components were purified by DEAE-cellulose, SP-Sephadex, and gel filtration chromatography. The matrix-bound component was eluted as a distinct peak from the free component in the above chromatographic systems. Amino acid composition of the purified matrixbound component indicated that this component consisted of phosphophoryn and collagen in the ratio of 2:3 based on the number of the residues. The matrix-bound component could not be reconstituted by mixing phosphophoryn with collagen CNBr peptides. Artificial crosslink products of free phosphophoryn and collagen CNBr-peptides by the carbodiimide method showed similar properties to the physiological matrix-bound phosphophoryn. The bond between phosphophoryn and collagen of the matrix-bound component is assumed to be a covalent crosslink.
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    Proteolipid-lipid relationships in normal and vitamin D-deficient chick cartilage (1984)
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    Calcified tissue international 36 (1984), S. 332-337 
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    ISSN: 1432-0827
    Keywords: Proteolipid ; Phospholipids ; Vitamin D ; Calcification ; Cartilage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Previous studies have shown thatin vitro calcification of chick epiphyseal cartilage matrix vesicles is proteolipid-dependent. The purpose of this research is to examine the role of proteolipid in cartilage calcificationin vivo by comparing the proteolipid concentration of normal and vitamin D-deficient chick epiphyseal cartilage, the relationship of proteolipid to other tissue lipids, and its ability to supportin vitro apatite formation. Proteolipid was isolated from the upper growth centers (reserve cell zone, upper proliferative zone) and lower growth centers (lower proliferative, hypertrophic, and calcified cartilage zones) of long-bone epiphyses from 3-week-old normal and rachitic male white leghorn chicks by Sephadex LH-20 chromatography of the crude phospholipid component of the total lipid extract. In both normal and rachitic tissue the proteolipid/dry weight and proteolipid/total lipid ratios were greater in the lower growth center than in the upper zones. No statistically significant change in the proteolipid/total lipid ratio in rachitic tissues relative to comparable cell zones in normal cartilages was observed. However, there was an increase in the nonproteolipid phospholipid content of rachitic tissues, altering the relative proteolipid/phospholipid composition. Whereas proteolipids from normal tissue supportedin vitro calcification, proteolipids from rachitic tissues did not, indicating a direct effect of vitamin D on proteolipid structure. These data support the hypothesis that failure of rachitic cartilage to calcifyin vivo may be due in part to alterations in phospholipid and proteolipid metabolism.
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    Variation in the biochemical properties of the Drosophila alcohol dehydrogenase allozymes (1984)
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    Biochemical genetics 22 (1984), S. 153-168 
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    ISSN: 1573-4927
    Keywords: alcohol dehydrogenase ; Drosophila ; activity ratio ; specific activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Thirteen Drosophila Adh variants have been characterized with respect to gene expression, substrate preference, thermostability, and specific activity. The results suggest that the variants may be grouped into two biochemical classes, typified by the properties of the two most common enzyme forms, ADH-F and ADH-S. Membership of these classes cannot be predicted from electrophoretic mobility, nor is any simple classification possible with regard to the characteristics of level of gene expression (in terms of ADH activity or ADH protein) or thermostability of the gene product.
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    Acetaldehyde utilization and toxicity in Drosophila adults lacking alcohol dehydrogenase or aldehyde oxidase (1984)
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    Biochemical genetics 22 (1984), S. 1015-1029 
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    ISSN: 1573-4927
    Keywords: acetaldehyde ; alcohol dehydrogenase ; aldehyde oxidase ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Metabolic utilization and toxicity of acetaldehyde were studied in flies lacking alcohol dehydrogenase (ADH), aldehyde oxidase (AO), or both functions. Prior to the experiments, mutant alleles Adh n4 and mal were transferred to the same genetic background by 10 successive backcrosses. By comparison with wild-type flies, various deleterious, pleiotropic effects could be attributed to the mal allele but not to Adh n4 . Of the four genotypes studied (mal, Adh n4 , mal Adh n4 , and wild), all were able to use acetaldehyde as a resource in a similar way. In spite of its high toxicity, acetaldehyde appeared a better resource than ethanol. Flies treated with intermediate acetaldehyde concentrations (around 0.5%) exhibited a very high interindividual heterogeneity which could reflect a physiological adaptation occurring as a consequence of the aldehyde treatment. Toxicity tests showed that ADH-negative flies were more sensitive to acetaldehyde than wild type, but this is most likely explained by the transformation of the aldehyde into alcohol. Our results show that the aldehyde metabolizing enzyme (AME) system in Drosophila is neither ADH nor AO. The existence of an aldehyde dehydrogenase is plausible.
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    Correlated response to phototactic selection (1984)
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    Behavior genetics 14 (1984), S. 279-293 
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    ISSN: 1573-3297
    Keywords: phototaxis ; Drosophila ; correlated response ; selection ; sepia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Artificial selection for positive and negative phototaxis was conducted in populations ofDrosophila melanogaster that were polymorphic at thesepia locus. Photoselection response was accompanied by a correlated response in the frequency of thesepia allele. Changes insepia frequency were shown to be significantly different from those predicted by several neutral models. Implications of this correlated response are briefly discussed in terms of the neurogenetic basis of phototaxis.
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    A note on barometric pressure and behavior inDrosophila pseudoobscura (1984)
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    Behavior genetics 14 (1984), S. 315-317 
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    ISSN: 1573-3297
    Keywords: Drosophila ; mating and barometric pressure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract During a study ofDrosophila mating behavior we observed unexpected changes in performance under ostensibly identical experimental conditions. We related the behavior during the 17 days of the experiment to changes in ambient humidity and barometric pressure. Humidity had no significant effect, but reduced barometric pressure was found to be associated with reduced mating activity (R 2=0.29,P〈0.025), accounting for close to 30% of the variation in total number of matings.
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    Genetic elements of courtship inDrosophila: Mosaics and learning mutants (1984)
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    Behavior genetics 14 (1984), S. 383-410 
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    ISSN: 1573-3297
    Keywords: Drosophila ; courtship ; learning ; circadian
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
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    Genetic analysis of sex appeal inDrosophila (1984)
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    Behavior genetics 14 (1984), S. 411-440 
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    ISSN: 1573-3297
    Keywords: Drosophila ; courtship ; pheromones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
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    Drosophila Learning: Behavior and biochemistry (1984)
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    Behavior genetics 14 (1984), S. 527-557 
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    ISSN: 1573-3297
    Keywords: Drosophila ; learning ; classical conditioning mutants ; cAMP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
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    A few chemical words exchanged byDrosophila during courtship and mating (1984)
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    Behavior genetics 14 (1984), S. 441-478 
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    ISSN: 1573-3297
    Keywords: Drosophila ; courtship ; pheromones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Summary Experimental evidence and speculation relative to chemical messages exchanged byDrosophila during courtship and mating are reviewed. Only the speciesD. melanogaster andD. simulans are considered in detail. Emphasis is put on female aphrodisiacs, as they clearly participate in sex and species recognition. All the aphrodisiac molecules described are unsaturated long-chain hydrocarbons, and position 7 for a double bond seems important in both species. InD. melanogaster, only females are able to make 7,11-dienes, compounds which stimulate males of this species to court. InD. simulans, 7-tricosene plays a similar role but is produced by both sexes as well as maleD. melanogaster. In both species, polymorphism is shown for these molecules. Their biosynthesis is also considered and both preliminary biochemical and genetic data are introduced. Male-specific compounds which regulate male and female behaviors are also reviewed. For example,cis-vaccenyl acetate inhibits male courtship; one or two peptides control the female's receptivity and egg laying. Such compounds are transferred from males to females together with sperm.
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    A reexamination of the negative assortative mating phenomenon and its underlying mechanism inDrosophila melanogaster (1984)
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    Behavior genetics 14 (1984), S. 45-61 
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    ISSN: 1573-3297
    Keywords: assortative mating ; polymorphism ; partner selection ; pheromone ; behavior ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Averhoff and Richardson [(1974)Behav. Genet. 4:207–225] reported a trend toward negative assortative mating inDrosophila melanogaster during the course of inbreeding. These authors proposed that the underlying mechanism was based on pheromone polymorphism and male selection. Mass mating experiments were carried out to verify their hypothesis, detailed behavior observations were made to identify the underlying mechanism, and sex pheromone composition and variation were examined by using gas chromatography-mass spectrometry analysis. The results showed that negative assortative mating is not a general phenomenon. Although male pheromones are probably polymorphic, female pheromones are not. We found no evidence for male selection as predicted by Averhoff and Richardson. It is argued that the most parsimonious mechanism underlying negative assortative mating is similar to one proposed by Bryant [(1979)Behav. Genet. 9:249–256], which was based on interstrain differences in female reluctancy and male vigor.
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    The analysis of mating behavior data (1984)
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    Behavior genetics 14 (1984), S. 153-156 
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    ISSN: 1573-3297
    Keywords: mating behavior ; statistical analysis ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Quite different sets of data are shown to generate identical output ratios so that analyses of mating behavior data based on the use of input and output ratios may obscure significant aspects of the mating behavior.
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    Learning in three species of diptera: The blow flyPhormia regina, the fruit flyDrosophila melanogaster, and the house flyMusca domestica (1984)
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    Behavior genetics 14 (1984), S. 479-526 
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    ISSN: 1573-3297
    Keywords: Drosophila ; learning ; conditioning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
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    Calcification initiation sites in the crab cuticle: The interprismatic septa (1984)
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    Cell & tissue research 236 (1984), S. 413-420 
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    ISSN: 1432-0878
    Keywords: Calcification ; Crab cuticle ; Cell coat glycoprotein ; Carbonic anhydrase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the crab cuticle the interprismatic septa (IS), which correspond to imprints left in the cuticle by the margins of the epidermal cells, penetrate the twisted structure of the chitin-protein matrix. The ultrastructure and geometric relationship between the fibrous architecture and the pattern of the prisms is described. The cytochemical characterization of the IS, by pronase treatment and ruthenium red staining, supports the hypothesis that this material corresponds to cell-coat glycoproteins released in the cuticle during secretion of the organic matrix. Calcification begins after ecdysis in the external laminae of the pigmented layer and along the IS. The presence of cation-binding glycoproteins in the sites where calcification is initiated could induce the nucleation of the mineral phase by concentrating calcium. The extracellular distribution of carbonic anhydrase, which favours carbonate deposition, is observed on ultrathin sections over the IS.
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    Synthesis and transport of the organic matrix of the spicules in the gorgonian Leptogorgia virgulata (Lamarck) (Coelenterata: Gorgonacea) (1984)
    Springer
    Cell & tissue research 235 (1984), S. 533-538 
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    ISSN: 1432-0878
    Keywords: Gorgonians ; Organic matrix ; Autoradiography ; Calcification ; Leptogorgia virgulata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The sequence of the synthesis and transport of the organic matrix of spicules has been elucidated in the gorgonian Leptogorgia virgulata by use of 3H-aspartic acid as the tracer in electron-microscopic autoradiography. The entire process of matrix synthesis and transport takes approximately 2 h. It seems that the protein moiety of the organic matrix is synthesized in the RER prior to 5 min following the initial 10 min incubation in the tracer. At the 5 min chase the label is moving from the RER to the Golgi complexes where the carbohydrate moiety of the matrix is presumed to be synthesized. At the 5 to 15 min chases the label is transported out of the Golgi complexes via Golgi vesicles. This phase continues for 30 min. From 60 to 120 min the 3H-aspartic acid moves to the spicules. After 120 min the majority of the label has moved into the spicules. Silver grain counts over both multivesicular and electron-dense bodies remain at relatively low and constant levels over 4 h indicating that neither organelle is involved in the synthesis and transport of the organic matrix.
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    Electron microscopy and microanalysis of a subcutaneous heterotopic calcification (1983)
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    Calcified tissue international 35 (1983), S. 723-727 
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    ISSN: 1432-0827
    Keywords: Calcification ; Scleroderma ; CRST syndrome ; High resolution TEM ; Microanalysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary This paper reports the study of a subcutaneous heterotopic calcification from a patient with Thibierge-Weissenbach's syndrome, a type of creeping scleroderma included in the CRST syndrome. These local deposits, whose origin is still unknown, are commonly considered to be a classic apatite phase. Using SEM, high resolution TEM, electron diffraction, infrared spectrometry, and SEM and TEM microanalysis, it is demonstrated that this material is highly heterogeneous and appears in a nonstoichiometric, carbonated, calcium ion-deficient apatitic solid phase. Our study shows the co-existence of dense globules presenting an ill-organized, more or less amorphous phase (ACP) or microcrystalline (OCP, β tricalcium phosphate), with scattered apatite crystals, and of interglobular apatite crystals with a good cristallinity.
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    URL: http://dx.doi.org/10.1007/BF02405113
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    Correlated physicochemical and age changes in embryonic bovine enamel (1983)
    Springer
    Calcified tissue international 35 (1983), S. 48-55 
    Details
    ISSN: 1432-0827
    Keywords: Enamel ; Density centrifugation ; Hydroxyapatite ; Carbonate ; Calcification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Whole enamel scrapings from unerupted teeth of embryonic calves have been separated into fractions of varying density by stepwise centrifugation in bromoform-toluene mixtures of increasing specific gravity. Partition of enamel in this manner yields individual fractions of increasing mineral phase age and maturation. Whole scrapings and isolated fractions of the fetal bovine enamel were examined by X-ray powder diffraction, scanning electron microscopy, and atomic absorption and infrared spectroscopy to determine time-related changes in the physicochemical nature of the constituent mineral phase particles. These analyses showed poorly crystalline hydroxyapatite (HA) as the only detectable solid phase of calcium phosphate present in all fractions, its degree of crystallinity increasing with increasing density. Molar Ca/P ratios and magnesium content were highest in lowest density fractions. Carbonate vibration bands at 875 and 1420–1450 cm−1, common to mineralized tissue, were observed in intermediate and higher density fractions and in whole unfractionated enamel. Another carbonate band at ∼705 cm−1, unusual to vertebrate calcified tissue, was detected in low density fractions and disappeared rapidly with increasing enamel maturation. Its precise relation with the enamel mineral phase has not been determined.
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    URL: http://dx.doi.org/10.1007/BF02405006
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    The role of the peripodial membrane in the morphogenesis of the eye-antennal disc ofDrosophila melanogaster (1983)
    Springer
    Development genes and evolution 192 (1983), S. 164-170 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Imaginal disc ; Morphogenesis ; Tissue culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The early morphogenesis of the eye-antennal disc ofDrosophila in response to 20-hydroxy ecdysone involves the curling of the eye anlagen dorsally over the antenna. During this process, the area of the peripodial membrane is substantially reduced. The peripodial membrane is taut at this stage, and if it is cut the curling of the disc cannot continue, and the eye anlagen returns to its original position within one minute of the operation. In contrast, cutting the columnar epithelium between the eye and antennal anlagen does not disrupt curling, but actually facilitates it. During curling, the cells of the peripodial membrane appear healthy, and exhibit basal extensions. We suggest that the curling of the eye is mediated by the conversion of cuboidal peripodial membrane cells into pseudostratified columnar epithelium at the edges of the peripodial membrane. Subsequently, cells of the peripodial membrane secrete first a pupal cuticle, and then an imaginal cuticle.
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    URL: http://dx.doi.org/10.1007/BF00848686
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    The evagination of the genital imaginal discs ofDrosophila melanogaster (1983)
    Springer
    Development genes and evolution 192 (1983), S. 275-279 
    Details
    ISSN: 1432-041X
    Keywords: Evagination ; Morphogenesis ; Metamorphosis ; Female genital disc ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The morphology of the evaginating female genital disc ofDrosophila melanogaster was examined at different stages of metamorphosis. The observations show that the internal genital organs are derived from the anterior half of the disc and that their morphogenesis is mainly a protrusion of the different primordial areas of the disc epithelium. The external genital and anal derivatives originate from the posterior half of the disc, which undergoes complex rearrangements during metamorphosis. The disc opens along the posterior margin and the dorsal and ventral epithelia evert and thereby completely reverse their anteroposterior orientation. Dramatic elongation has been observed during the formation of the seminal receptacle. The cells of the repressed male genital primordium do not form any recognizable structures and are assumed to be eliminated during metamorphosis.
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    URL: http://dx.doi.org/10.1007/BF00848660
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    The effect of 5-azacytidine and cytidine analogs onDrosophila melanogaster cells in culture (1983)
    Springer
    Development genes and evolution 192 (1983), S. 299-302 
    Details
    ISSN: 1432-041X
    Keywords: Differentiation ; Teratogens ; Drosophila ; 5-Azacytidine ; Methylation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The effects of cytidine and cytidine analogs were studied inDrosophila embryonic cell cultures and two wild-type established cell lines, Oregon-R and Schneider line 2. Primary embryonic cultures have been shown to be an excellent system for the study of embryonic development; a number of cell types undergo normal differentiation in vitro. Treatment of these cultures with putative teratogens resulted in an inhibition of muscle and/or neuron differentiation in our study. Treatment of these cells with cytidine and seven other analogs had no effect on neuron and muscle differentiation. The compound 5-azacytidine, when added to primary cell cultures, inhibited normal differentiation at subtoxic doses while inducing the production of three proteins that comigrate with the heat-shock proteins, hsp 23, 22a and 22b. 5-Azacytidine did not stimulate differentiation in Oregon-R or SchneiderDrosophila cell lines. The in vitro blockage of differentiation by 5-azacytidine suggests that it may act as a teratogen.
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    URL: http://dx.doi.org/10.1007/BF00848664
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    The evagination of the genital imaginal discs ofDrosophila melanogaster (1983)
    Springer
    Development genes and evolution 192 (1983), S. 280-284 
    Details
    ISSN: 1432-041X
    Keywords: Evagination ; Morphogenesis ; Metamorphosis ; Intersexual genital disc ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Morphogenetic movements of the intersexual genital disc of thedoublesex-dominant mutant ofDrosophila melanogaster were followed during metamorphosis. Intersexual genital discs contain well developed genital primordia of both sexes as well as an anal primordium, and all of these primordia evaginate simultaneously. The female genital primordium is deflected to the ventral side by the male genital primordium which is located anterior to it. Subsequently the anterior parts of the two genital primordia project their internal appendages in parallel in the anterior direction. The morphogenetic movements closely resemble those of the corresponding parts of normal males and females. The disc opens at the stalk along the posterior edge and the two genital primordia completely evert their posterior parts. These areas undergo complex rearrangements whereby the anlage for the male genital arch as well as that for the 8th tergite evert and move around the lateral side of the disc. They both fuse dorsally after enclosing the anal tube. The formation of the characteristic abnormalities of the intersexual genitalia seems not to result simply from spatial problems of the simultaneous evagination of the genital anlagen but rather to be a direct result of the ambiguous genetic signalling in the intersexual cells of these primordia.
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    Cell lineage restrictions in the genital disc ofDrosophila revealed byMinute gynandromorphs (1983)
    Springer
    Development genes and evolution 192 (1983), S. 337-346 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Gynandromorphs ; Genital disc ; Compartments ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The genital imaginal disc ofDrosophila differentiates the terminalia, i.e. the genitalia and analia, of both sexes. It represents a composite anlage, containing a female genital primordium, a male genital primordium and an anal primordium. In normal males and females, only one of the two genital primordia differentiates; the other is developmentally repressed. Therefore, cell-lineage relationships between the male and female genital primordia can only be studied in sexual mosaics which differentiate female and male cells. We producedMinute (M)‖non-Minute(M+) gynandromorphs and selected those with sexually mosaic terminalia for a cell-lineage analysis. In these mosaics, either the male (XO) or female (XX) cells wereM + and thus had a growth advantage. The differential growth rates served as a tool to detect clonal restrictions. In control gynandromorphs (M +‖M +), the amount of female genitalia differentiated was largely independent of the amount of male genitalia present. In contrast, male and female anal structures, as a rule, added up to one full set. The same was true for the experimentalM‖M + gynandromorphs, but the contribution ofXX andXO cells to mosaic terminalia changed drastically due toM + cells competing successfully against the more slowly growingM cells. Specific subsamples ofM‖M + gynandromorphs showed thatM cells in a non-mosaic primordium are shielded from cell competition taking place in the neighbouring mosaic primordium. We conclude that the three primordia of the genital disc represent developmental compartments. In the genital primordia, even developmentally repressedM + cells compete successfully against developmentally activeM cells.
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    URL: http://dx.doi.org/10.1007/BF00848814
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    Development of imaginal discs from lethal hybrids betweenDrosophila melanogaster andDrosophila mauritiana (1983)
    Springer
    Development genes and evolution 192 (1983), S. 48-50 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Hybrid lethality ; Imaginal discs ; Interspecific transplantation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Females ofDrosophila melanogaster, crossed with males ofDrosophila mauritiana, produce only female offspring. The male hybrid larvae grow very slowly, fail to pupate and die after prolonged larval life. Imaginal discs from these male hybrids transplanted into Drosophila melanogaster larvae can give rise to adult structures with normal patterns. Differentiation of hybrid imaginal disc tissue is improved by short term culture in non-hybrid larvae prior to metamorphosis, suggesting that the hybrid larval haemolymph is inadequate to sustain normal imaginal disc growth. This may represent the physiological basis of the reproductive isolating mechanism separating the twoDrosophila species
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    Three-dimensional fate map of the female genital disc ofDrosophila melanogaster (1983)
    Springer
    Development genes and evolution 192 (1983), S. 270-274 
    Details
    ISSN: 1432-041X
    Keywords: Fate map ; Repressed primordium ; Sex determination ; Genital disc ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The female genital disc ofDrosophila melanogaster was cut into distinct fragments, and the prospective fates of the fragments were determined by putting them through metamorphosis in host larvae. The dorsal epithelium contains the anlagen for the anal plates and parovaria, as well as the repressed male genital primordium. The ventral epithelium gives rise to all of the female genital structures except for the parovaria. The results were compared with published fate maps and observations made in experiments with sex-transforming mutations. This allowed us to establish a detailed three-dimensional fate map of the female genital disc, which shows a well-developed female genital primordium in the ventral epithelium, a repressed male genital primordium in the anterior part of the dorsal epithelium and an anal primordium in the posterior region of the dorsal disc epithelium.
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    Cell degeneration and elimination in the imaginal wing disc, caused by the mutationsvestigial andUltravestigial ofDrosophila melanogaster (1983)
    Springer
    Development genes and evolution 192 (1983), S. 285-294 
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    ISSN: 1432-041X
    Keywords: Drosophila ; Cell degeneration ; Imaginal disc ; Basal lamina ; Blood cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The mutationsvestigial (vg; recessive) andUltravestigial (vg U; dominant) ofDrosophila melanogaster give rise to identical mutant adult phenotypes in which much of the cases this results from cell death in the presumptive wing margin of the wing disc in the third larval instar, but the process of cell degeneration is quite different in the two mutants. Invg cell death occurs continuously throughout the third larval instar, while invg U it occurs only in the early third instar. Cells fragment and some of the fragments condense, becoming electron dense (“apoptosis”). Both condensed and ultrastructurally normal cell fragments are extruded to the basal side of thevg disc epithelium. They accumulate under the basal lamina in the wing pouch area until they are phagocytosed by blood cells entering the wing pouch during the six hours following pupariation. Fragments are not extruded from thevg U epithelium but are apparently phagocytosed by neighboring epithelial cells. The basal lamina undergoes mophological changes following pupariation and is phagocytosed by blood cells in both wild-type andvestigial, but investigial the degenerated cell fragments are also engulfed by the same blood cells.
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    Topological specificity of phenotype expression of neurogenic mutations inDrosophila (1983)
    Springer
    Development genes and evolution 192 (1983), S. 317-326 
    Details
    ISSN: 1432-041X
    Keywords: Neurogenic mutations ; Topological specificity ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Neurogenic mutations have been found to cause the neuralization of certain regions of the ectoderm and yet to permit normal development of the remaining embryonic cells. Thus, it seems that the activity of the wild-type alleles of these genes is dispensable in a considerable fraction of the embryo during wild-type development. This effect might be a consequence of the cells' position within the embryo; alternatively, it might be independent of the position but be due rather to the genetic activity experienced by the cells previous to their commitment. The results described in this paper indicate that genes controlling patterning along the embryonic dorso-ventral perimeter (dorsal and Toll) are epistatic to genes controlling neurogenesis, their activity deciding which ectodermal cells are susceptible to neurogenesis. Using alleles with low expressivity, evidence was obtained showing that the tracheal placodes define the boundary of the territory which has neurogenic abilities at thoracic and abdominal levels.
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    URL: http://dx.doi.org/10.1007/BF00848811
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    On the phenotype and development of mutants of early neurogenesis inDrosophila melanogaster (1983)
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    Development genes and evolution 192 (1983), S. 62-74 
    Details
    ISSN: 1432-041X
    Keywords: Early neurogenesis ; Neurogenic mutants ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The central nervous system (CNS) ofDrosophila develops from precursor cells called neuroblasts. Neuroblasts segregate in early embryogenesis from an apparantly undifferentiated ectoderm and move into the embryo, whereas most of the remaining ectodermal cells continue development as epidermal cell precursors. Segregation of neuroblasts occurs within a region called the neurogenic field. We are interested in understanding how the genome ofDrosophila controls the parcelling of the ectoderm into epidermal and neural territories. We describe here mutations belonging to seven complementation groups which effect an abnormal neurogenesis. The phenotypes produced by these mutations are similar. Essential features of these phenotypes are a conspicuous hypertrophy of the CNS accompanied by epidermal defects; the remaining organs and tissues of the mutants are apparently unaffected. The study of mutant phenotype development strongly suggests this phenotype to be due to misrouting into the neural pathway of development of ectodermal cells which in the wildtype would have given rise to epidermal cells, i.e. to an initial enlargement of the neurogenic region at the expense of the epidermogenic region. These observations indicate that the seven genetic loci revealed by the mutations described in this study contribute to control the neurogenic field. The present results suggest that in wildtype development neurogenic genes are supressed within all derivatives of the mesoderm and endoderm and some derivatives of the ectoderm, and conditionally expressed in the remaining ectoderm. The organisation of the neurogenic field in the wildtype is discussed.
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    URL: http://dx.doi.org/10.1007/BF00848482
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    Ultrastructural cytochemistry of complex carbohydrates in osteoblasts, osteoid, and bone matrix (1983)
    Springer
    Calcified tissue international 35 (1983), S. 309-319 
    Details
    ISSN: 1432-0827
    Keywords: Calcification ; Glycosaminoglycan ; Glycoprotein ; Collagen ; Acid phosphatase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Glycosaminoglycans (GAGs) and glycoproteins are essential components for osteogenesis. We have examined rat osteoblasts, osteoid, transitional zone, and fully calcified bone matrix, utilizing Spicer's high-iron diaminethiocarbohydrazide-silver protein (HID-TCH-SP) method for sulfated glycoconjugates and Thiéry's periodate-TCH-SP (PA-TCH-SP) method for vicinal glycol-containing glycoconjugates. HID-TCH-SP stained cytoplasmic granules of osteoblasts. Stain deposits in the extracellular matrix were observed in decreasing amounts in osteoid, the transitional zone, and fully calcified bone matrix. Enzyme digestion with testicular hyaluronidase removed most HID-TCH-SP stain deposits. PA-TCH-SP staining was observed with increasing intensity in rough endoplasmic reticulum, Golgi saccules, and cytoplasmic granules. Collagen fibrils in osteoid were weakly stained with PA-TCH-SP, and their staining appeared even weaker in fully calcified bone matrix. In contrast, collagen fibrils in calcified cartilage stained intensely with the PA-TCH-SP method. Focal circular profiles (0.1–0.5µm in diameter), which lacked collagen fibrils but reacted moderately with PA-TCH-SP, were frequently seen in the transitional zone and fully calcified bone matrix, but were only occasionally present in osteoid. The presence of testicular hyaluronidase-resistant GAG and acid phosphatase in these focal areas suggests that they represent sites of GAG degradation. The eventual loss of HID-TCH-SP staining in the bone matrix suggests that removal of sulfated glycoconjugates may be a requisite for expansion of initial calcification sites and/or complete calcification.
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    URL: http://dx.doi.org/10.1007/BF02405052
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    An intermediate state in hydrolysis of amorphous calcium phosphate (1983)
    Springer
    Calcified tissue international 35 (1983), S. 783-790 
    Details
    ISSN: 1432-0827
    Keywords: Amorphous calcium phosphate ; Apatite ; Calcification ; Hydrolysis ; Octacalcium phosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The hydrolysis of previously prepared amorphous calcium phosphate (ACP) was studied in a solution “saturated” with ACP; this eliminated the initial consumption of acid due to ACP dissolution. The procedure established that conversion of a high-concentration ACP slurry to an apatite involves two processes: the first process consumes acid and indicates the formation of a more acidic calcium phosphate intermediary with the solubility of octacalcium phosphate (OCP); the second process consumes base and indicates the conversion of the intermediary to apatite and, possibly, direct conversion of ACP to apatite. The thermodynamic analysis of the solution composition data suggests that ACP converts into a nonstoichiometric apatite when the OCP-like intermediary is formed, and a stoichiometric apatite is formed when no OCP-like intermediary is involved.
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    URL: http://dx.doi.org/10.1007/BF02405124
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    32Pi- and45Ca-metabolism by matrix vesicle-enriched microsomes prepared from chicken epiphyseal cartilage by isosmotic percoll density-gradient fractionation (1983)
    Springer
    Calcified tissue international 35 (1983), S. 327-338 
    Details
    ISSN: 1432-0827
    Keywords: Matrix vesicles ; 32P-phosphate and45Ca-metabolism ; Epiphyseal cartilage ; Calcification ; Alkaline phosphatase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Matrix vesicle-enriched fractions were isolated from different zones of epiphyseal cartilage by nonenzymatic methods involving tissue homogenization, differential centrifugation, and isosmotic Percoll gradient fractionation. Uptakes of both32Pi and45Ca were studied concomitantly over periods from 20 min to 24 h. Percoll density gradients separated epiphyseal microsomes into two alkaline phosphatase-rich fractions: a low-density noncalcifiable fraction (P-I), and a higher-density fraction (P-II) which readily mineralized. The P-II fraction was found only in calcifying regions of the growth plate. Based on chemical and physical properties and enzyme activities, both fractions were similar except that P-II contained significantly higher levels of mineral ions than did P-I, and had lower levels of alkaline phosphatase. The mineral appeared to be primarily in a noncrystalline form. Metabolism of32Pi and45Ca by P-II followed a complex kinetic pattern in which accumulation of large amounts of both ions was preceded by an initial limited burst of uptake and a lag-phase of variable duration. During mineral ion loading, the density of the P-II fraction progressively increased as evidenced by co-migration of45Ca,32Pi, and alkaline phosphatase to increasingly higher densities. During the period of early mineral deposition (1–5 h), Ca/P uptake ratios were very low (1.0–1.2) and X-ray diffraction patterns showed a predominantly amorphous pattern. This suggests that the mineral accumulated in matrix vesicles is initially some form of noncrystalline calcium monohydrogenphosphate. L-tetramisole, a potent inhibitor of alkaline phosphatase, inhibited accumulation of both45Ca and32Piin the absence of organic P substrates,32Pi being preferentially inhibited over45Ca. This finding, coupled with recent studies on the behavior of alkaline phosphatase at physiological pH, suggests that the protein is not acting as a phosphohydrolase, but rather as a Pi-binding or transport agent in vesicle-mediated calcification.
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    Drosophila lactate dehydrogenase: Developmental aspects (1983)
    Springer
    Biochemical genetics 21 (1983), S. 199-211 
    Details
    ISSN: 1573-4927
    Keywords: Drosophila ; lactate dehydrogenase ; isozymic pattern ; development ; isozymic conversion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Partially purified lactate dehydrogenase (LDH) from third-instar larvae displays two bands (one major and one minor) on polyacrylamide gels. Analogous preparations from pupae and adults exhibit three LDH-staining bands (one major and two minor) in a similar pattern. The migration of the major band is similar for larvae, pupae, and adults, while the two minor LDH bands of pupae and adults migrate more slowly than the minor larval band. It has been shown that larval LDH incubated with β-nicotinamide adenine dinucleotide exhibits two additional minor bands with an electrophoretic mobility similar to that of the minor bands of both pupae and adults. The intensity of the minor larval LDH band (exhibited also by untreated preparations) is drastically reduced. This fact indicates that the life-cycle stage-dependent LDH isozymic distribution is possibly due to a posttranslational effect(s). Highly purified LDH from larvae, pupae, or adults, obtained by an affinity chromatography procedure, displays just one dispersed band, located in the area between the band 5 and the band 6 exhibited by crude extract preparations. These data, in combination with the lack of difference in catalytic properties among enzymes from larvae, pupae, and adults, suggest that LDH synthesis is controlled by the same single structural gene at all developmental stages.
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    Drosophila lactate dehydrogenase: Developmental aspects (1983)
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    Biochemical genetics 21 (1983), S. 199-211 
    Details
    ISSN: 1573-4927
    Keywords: Drosophila ; lactate dehydrogenase ; isozymic pattern ; development ; isozymic conversion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Partially purified lactate dehydrogenase (LDH) from third-instar larvae displays two bands (one major and one minor) on polyacrylamide gels. Analogous preparations from pupae and adults exhibit three LDH-staining bands (one major and two minor) in a similar pattern. The migration of the major band is similar for larvae, pupae, and adults, while the two minor LDH bands of pupae and adults migrate more slowly than the minor larval band. It has been shown that larval LDH incubated with β-nicotinamide adenine dinucleotide exhibits two additional minor bands with an electrophoretic mobility similar to that of the minor bands of both pupae and adults. The intensity of the minor larval LDH band (exhibited also by untreated preparations) is drastically reduced. This fact indicates that the life-cycle stage-dependent LDH isozymic distribution is possibly due to a posttranslational effect(s). Highly purified LDH from larvae, pupae, or adults, obtained by an affinity chromatography procedure, displays just one dispersed band, located in the area between the band 5 and the band 6 exhibited by crude extract preparations. These data, in combination with the lack of difference in catalytic properties among enzymes from larvae, pupae, and adults, suggest that LDH synthesis is controlled by the same single structural gene at all developmental stages.
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    Alcohol dehydrogenase thermostability variants in Drosophila melanogaster: Comparison of activity ratios and enzyme levels (1983)
    Springer
    Biochemical genetics 21 (1983), S. 1071-1088 
    Details
    ISSN: 1573-4927
    Keywords: Drosophila ; alcohol dehydrogenase ; enzyme polymorphisms, activity ratios
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Representatives of five allozymic classes of Drosophila alcohol dehydrogenase have been compared with respect to their activity levels on two alcohol substrates, quantities of ADH protein, and stability in crude extracts. Within each allozymic class, strains from widely diverse geographic locations differ in their enzyme activity levels but are identical for a measure known as “activity ratio,” which is obtained by dividing the average activity reading on isopropanol by that obtained with ethanol. They are also similar in the rate at which ADH activity declines in crude extracts held at 25°C. For several of the fast-resistant and fast-moderate strains, differences in ADH activity are associated with differences in the amount of enzyme present. The catalytic efficiencies of the fast-resistant forms are considerably lower than those of the fast-moderate allozymes. The origin and persistence of the rare but ubiquitous fast-resistant allozyme is discussed.
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    Genetic localization and sequential electrophoresis of glucose-6-phosphate dehydrogenase in Drosophila melanogaster (1983)
    Springer
    Biochemical genetics 21 (1983), S. 703-711 
    Details
    ISSN: 1573-4927
    Keywords: Drosophila ; glucose-6-phosphate dehydrogenase ; polymorphism ; sequential electrophoresis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Studies were undertaken to investigate two critical aspects of the glucose-6-phosphate dehydrogenase polymorphism in Drosophila melanogaster. The first investigation unequivocally maps the genetic site of the G6PD locus to the X chromosome. The second study subjects a set of isochromosomal lines to sequential electrophoresis in an attempt to uncover common molecular heterogeneity within the global polymorphism, assuming that this variation may have gone undetected under conventional electrophoretic conditions. The genetic site was mapped following the segregation of the two common electrophoretic alleles, a so-called null allele, and two rare electrophoretic variants. From the pooled results, the Zw locus mapped to 62.9 on the X chromosome relative to the flanking markers car (at 62.5) and sw (at 64.7). A set of 126 iso-X chromosomal lines of diverse geographic origin was subjected to sequential electrophoresis under three different acrylamide conditions in addition to the conventional starch electrophoretic system. No additional variation beyond the common diallele polymorphism was seen.
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    Pupation site selection inDrosophila simulans (1983)
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    Behavior genetics 13 (1983), S. 17-27 
    Details
    ISSN: 1573-3297
    Keywords: pupation site ; pupation height ; artificial selection ; Drosophila ; density-dependent behavior ; genotype-environment interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Selection for increased pupation height was carried out for 17 generations in two lines ofDrosophila simulans derived from a genetically heterogeneous base population. The realized heritability for mean pupation height in each line, calculated over the 17 generations, did not differ significantly from zero. Both selected lines tended to pupate away from the center of the culture medium to a greater extent than the control in the latter generations of the experiment but not in earlier generations. Pupation height may have been refractory to artificial selection because of an adaptation of this species to pupate on the larval food source. In a subsequent experiment, each line was tested at three larval densities in an apparatus different from the one used for selection. Each successively higher density showed a corresponding increase in pupation height. Both selected lines had higher mean pupation heights than the control line. The differences between lines became more pronounced as the larval density increased.
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    URL: http://dx.doi.org/10.1007/BF01071741
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    The effect of alcohol stress on nicotinamide adenine dinucleotide (NAD+) levels in Drosophila (1983)
    Springer
    Biochemical genetics 21 (1983), S. 365-374 
    Details
    ISSN: 1573-4927
    Keywords: alcohol dehydrogenase ; NAD+ levels ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Previous studies carried out in mammalian systems indicated that an organism's NAD+/NADH balance is carefully regulated but can be destabilized by dietary stresses. Since Drosophila alcohol dehydrogenase (ADH) uses NAD+ to remove a hydrogen from ethanol in the first step of alcohol catabolism, it is possible that under alcohol stress conditions the in vivo NAD+ levels in Drosophila may decrease. In this study genetically homozygous flies were stressed with maximally sublethal concentrations of ethanol (10%) for periods of up to 24 hr. The results indicate that NAD+ levels do in fact drop by at least 20% in response to ethanol stress. Evidence is presented that suggests that this decrease is the direct result of ADH-mediated catabolism.
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    URL: http://dx.doi.org/10.1007/BF00499145
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    Effects of disruptive selection on genetic variance (1983)
    Springer
    Theoretical and applied genetics 65 (1983), S. 173-180 
    Details
    ISSN: 1432-2242
    Keywords: Disruptive selection ; Linkage disequilibrium ; Genetic variance ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Theoretical predictions of changes in variance with disruptive selection have used models of infinitely many genes so the increase in variance was necessarily due to linkage disequilibrium. With small numbers of loci, the disequilibrium is shown still to comprise the major part of the changes in variance. In a replicated experiment with Drosophila melanogaster, disruptive selection was practised for three generations, and this was followed by 5 or 7 generations of random mating. The heritability, as estimated from regression of progeny on parent, rose from 37% to 68% on selection, and subsequently declined to 45% on random mating. Changes of variance can be interpreted invoking the build up of linkage disequilibrium during selection followed by its breakdown upon relaxation. The results agree well with those obtained from Monte Carlo simulation.
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    URL: http://dx.doi.org/10.1007/BF00264888
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    Latitudinal variation in octanol dehydrogenase and acid phosphatase allele frequencies in Drosophila melanogaster (1983)
    Springer
    Theoretical and applied genetics 65 (1983), S. 191-196 
    Details
    ISSN: 1432-2242
    Keywords: Drosophila ; Enzyme polymorphisms ; Latitudinal clines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The octanol dehydrogenase (Odh) and acid phosphatase (Acph) loci of Drosophila melanogaster are each polymorphic for two electrophoretically detectable alleles. The frequencies of the Odh and Acph alleles have been analysed in populations sampled from up to a 40 ° latitudinal range in each of Australasia, North America and Europe/Asia. Odh S frequency is found to be significantly negatively associated with distance from the equator in all three zones. The relationship of Acph S frequency to distance from the equator is significant and negative in Australasia but neither significant nor consistent in sign in North America and Europe/Asia.
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    URL: http://dx.doi.org/10.1007/BF00308064
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    Ultrastructural polysaccharide localization in calcifying and naked cells of the coccolithophoridEmiliania huxleyi (1983)
    Springer
    Protoplasma 118 (1983), S. 157-168 
    Details
    ISSN: 1615-6102
    Keywords: Calcification ; Coccolithophorids ; Polysaccharide localization ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Emiliania huxleyi is a marine coccolithophorid which produces coccoliths,i.e., particles consisting of calcite and macromolecular organic material. The coccoliths are formed intracellulary in specialized organelles which comprise a coccolith vesicle (CV) and a reticular body (RB), together forming the CV/RB system or calcifying system. After termination of calcification, the coccolith is extruded and incorporated into the coccosphere,i.e., one or several layers of extracellular coccoliths surrounding the cell. Apart from the coccolith-producing cells (C cells) ofE. huxleyi, there are naked cells (N cells) which seem to have lost the capacity to produce coccoliths but are very similar to the C cells in other morphological respects. Biochemical studies have revealed that polysaccharides may play a regulatory role in calcification. The aim of the present study was to determine the localization of polysaccharides in both C and N cells electron microscopically. For this purpose, a cytochemical staining technique according toThiéry (1967) was applied. The CV/RB system of C cells was conspicuously stained. Due to the excellent stainability of this system, a putative succession of morphological stages during coccolithogenesis could be described. The staining pattern of the N cells closely resembled that of the C cells. It was found, however, that the “calcifying” system of N and C cells differed in both morphology and position. It is suggested that the divergent morphology of the “calcifying” system of N cells accounts for its failure to produce coccoliths.
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    URL: http://dx.doi.org/10.1007/BF01293073
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    An altered electroretinogram transient associated with an unusual jump response in a mutant ofDrosophila (1983)
    Springer
    Cellular and molecular neurobiology 3 (1983), S. 143-149 
    Details
    ISSN: 1573-6830
    Keywords: electroretinogram ; visual mutants ; visual sensitization ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. Mutations at thestoned locus ofDrosophila melanogaster produce a reversible temperature-sensitive debilitation. At permissive temperatures they also exhibit an unusual jump response to a light-off stimulus. 2. An increase in the amplitude of the off-transient of the electroretinogram (ERG) is associated with this abnormal jump. Both the jump response and the increased amplitude of the off-transient are shown to be dependent on the duration of the light pulse prior to the light-off stimulus. 3. Instoned flies which are light adapted, the jump response, as measured by recording from the indirect flight muscles, is seen to habituate with increasing light-off frequency. This habituation corresponds to the decrease in the amplitude of the off-transient that also occurs with high-frequency stimulation. 4. Another visual mutanttan, removes the off and on-transients of the ERG. 5. The combining of thestoned mutation withtan in thetan, stoned double mutant results in the loss of the jump behavior as well as the partial restoration of the off-transient to an otherwisetan-like ERG. The relationship between the increase in the amplitude of the off-transient instoned flies and the eliciting of the jump response is discussed.
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    URL: http://dx.doi.org/10.1007/BF00735278
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    The regulation of phosphorylation of a specific protein in synaptosomal fractions fromDrosophila heads: The effects of light and two visual mutants (1983)
    Springer
    Cellular and molecular neurobiology 3 (1983), S. 127-141 
    Details
    ISSN: 1573-6830
    Keywords: cyclic adenosine monophosphate ; calmodulin ; phosphorylation ; visual mutants ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. Protein IV from synaptosomal fractions ofDrosophila heads is phosphorylatedin vitro by an endogenous cyclic adenosine monophosphate (cAMP)-dependent protein kinase. Thein vivo phosphorylation of this protein is affected by light. 2. Two visual mutants,tan andstoned, exhibit altered levels ofin vivo phosphorylation of protein IV. Thetan strain shows depressedin vivo levels of phosphorylation of protein IV, whereasstoned shows an increase in thein vivo level of phosphorylation of this same protein. 3. Protein D is phosphorylatedin vitro by an endogenous Ca2+/calmodulindependent protein kinase and has a molecular weight identical to that of protein IV. Thestoned mutant strain shows an increase in thein vivo level of phosphorylation of protein D. 4. The data presented here suggest that the phosphorylation of protein IV, and perhaps D, may play a role in the early processing of visual information in the fly.
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    Activities of the nuclear envelope in the salivary glands of Drosophila (1983)
    Springer
    Cell & tissue research 228 (1983), S. 497-509 
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    ISSN: 1432-0878
    Keywords: Drosophila ; Larval salivary glands ; Nuclear “oval bodies” ; Annulate lamellae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Morphological data are presented concerning the single-membrane-bound vesicles (“oval bodies”) associated with the nuclear envelopes of larval salivary gland cells of Drosophila. Data are also presented concerning the existence of cytoplasmic annulate lamellae in these same cells. The mode of formation of these structures, as well as the relationships between them and with other cytoplasmic organelles are described. The possible functional significance of these phenomena is discussed.
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    URL: http://dx.doi.org/10.1007/BF00211471
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  • 88
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    Ultrastructure of the compound eye and first optic neuropile of the photoreceptor mutant ora JK84 of Drosophila (1983)
    Springer
    Cell & tissue research 233 (1983), S. 305-317 
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    ISSN: 1432-0878
    Keywords: Freeze fracture ; HVEM ; Retina ; Optic neuropile ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The developmental mutant of Drosophila (ora JK84) is characterized by nonfunctional photoreceptor cells (R1–6), while the R7/R8 cells are normal. A fundamental question is: Does the near absence of photosensitive membranes inhibit development of the Rl-6 axons and their synapses at the other end of the cell? The retina and first optic neuropile (lamina ganglionaris) were examined with freeze-fracture technique and high voltage electron microscopy. R1–6 have reduced rhabdomere caps; rhabdomeric microvilli have about 50% of the normal diameter and 20% of the normal length. Affected cells exhibit prominent vacuoles which appear to communicate with some highly convoluted microvillar membranes. Almost no P-face particles (putative rhodopsin molecules) are present in the R1–6 rhabdomeres, and particle densities are lower in R7 than previously reported. Near the rhabdomere caps, microvilli of R1–6 are fairly normal, but at more proximal levels they are greatly diminished in length and changed in orientation, while at still more proximal levels they are lost. R1–6, R7, and R8 axons from each ommatidium are bundled into normal pseudocartridges beneath the basement membrane. No abnormalities are found in the lamina ganglionaris, and all synaptic associations as well as the presumed “virgin” synapses (of R1–6) appear normal. No glial anomalies are present, and R7/R8 axons project through the lamina in the usual fashion. These fine structural findings are correlated with known electrophysiological, biochemical, and behavioral correlates of both sets of photoreceptors (R1–6, and R7/R8).
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    URL: http://dx.doi.org/10.1007/BF00238298
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    Multiple effects of colchicine on oogenesis in Drosophila: Induced sterility and switch of potential oocyte to nurse-cell developmental pathway (1983)
    Springer
    Cell & tissue research 228 (1983), S. 21-32 
    Details
    ISSN: 1432-0878
    Keywords: Drosophila ; Oogenesis ; Colchicine ; Microtubules ; Sterility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Adult female fruitflies exposed to colchicine admixed to the culture medium show a series of dosage-related abnormalities that affect oogenesis and may induce sterility. Among the effects observed were decreased fecundity and hatchability of laid eggs, formation of oocytes lacking chorionic appendages, abnormal distribution and diminution in number of yolk spheres, inhibition of oocyte growth and abnormally located oocyte nuclei. Potentially the most significant effect was the development of egg chambers which contained the normal complement of 16 cells but in which all the cells had the nuclear morphology of nurse cells. The approach provides for the first time an experimental means to divert a potential oocyte into the developmental pathway of the nurse cell in a wild-type fly, and hence should be helpful in the elucidation of factors which control oocyte and nurse cell differentiation. In addition, the results serve to expand the usefulness of oogenesis in Drosophila as a model system for the evaluation of drug-induced metabolic-morphologic abnormalities.
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    URL: http://dx.doi.org/10.1007/BF00206261
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    On the relation between genetic and environmental variability in animals (1982)
    Springer
    Journal of molecular evolution 18 (1982), S. 310-314 
    Details
    ISSN: 1432-1432
    Keywords: Neutral mutation theory ; Natural selection ; Protein evolution ; Levene model ; Environmental variability ; Genetic variability ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary If a phenotypic character is under stabilizing selection, the selective disadvantage of a nonoptimal genotype will decrease exponentially to zero as the proportion of phenotypic variation that is environmental in origin -V e /V p - increases. Under the modified mutation-drift hypothesis of genetic polymorphism, the proportion of mutations that are effectively neutral and average heterozygosity should increase with this ratio. Invertebrates, because of their small size, fast development, and low degree of homeostasis (relative to vertebrates), are expected to show a larger environmental component of phenotypic variation than vertebrates. This may help explain why invertebrates are in general more genetically variable than vertebrates and why, when laboratory populations ofDrosophila are maintained in heterogeneous environments, genetic variability is lost less rapidly than when they are kept in constant conditions.
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    URL: http://dx.doi.org/10.1007/BF01733897
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    Correlation between adult transformation and aldehyde oxidase staining pattern in wing discs ofApterous genotypes inDrosophila melanogaster (1982)
    Springer
    Development genes and evolution 191 (1982), S. 285-288 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Imaginal discs ; homoeosis ; Compartments ; Aldehyde oxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The aldehyde oxidase staining pattern in wing discs ofDrosophila melanogaster bearing the genotypesap blt /ap blt andap blt andap blt /ap 73n showns changes from the wild-type pattern. Extensive areas of the presumptive dorsal posterior wing blade, which are normally unstained, have enzyme activity in these mutants. In wings of these genotypes, dorsal posterior structures are replaced by dorsal anterior wing structures. A strong correlation has been found between the frequencies of various staining patterns in the discs and the extent of transformation in the cuticular structures of the wing, which is consistent with the idea that aldehyde oxidase activity can be used as an indicator in the wing disc of this transformation. Unlike the homoeotic mutationengrailed, apterous has not been interpreted as a selector gene yet the work reported here shows thatapterous alleles can cause changes resembling those of theengrailed phenotype both in aldehyde oxidase staining behaviour and in the cuticular transformation.
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    URL: http://dx.doi.org/10.1007/BF00848418
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    Effects of the “sexcombless” chromosome (In(1)sx) on males and females ofDrosophila melanogaster (1982)
    Springer
    Development genes and evolution 191 (1982), S. 264-269 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Sexcombless ; Foreleg basitarsus ; Genital disc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The chromosome which carries the mutationsexcombless (In(1)sx) affects males and females ofD. melanogaster. In the male foreleg basitarsi the number of sexcomb teeth is dramatically reduced from 10 to 0.7 and the number of transverse rows of bristles is increased from 6 to 8. Females homozygous forIn(1)sx show a normal bristle pattern in the foreleg basitarsus. The genital disc derivatives of both male and femaleIn(1)sx flies are strongly affected. While the external genitalia show a duplicated or a reduced bristle pattern, the internal genitalia are mostly absent. However, the sexually dimorphic tergites and sternites of the abdomen remain unaffected. The male-specific effect on the basitarsus and the general effects on the genital disc derivatives are proposed to represent two different phenotypic effects ofIn(1)sx which may derive from mutations at different gene loci in the inverted chromosome.
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    URL: http://dx.doi.org/10.1007/BF00848414
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    Growth is required for cell competition in the imaginal discs ofDrosophila melanogaster (1982)
    Springer
    Development genes and evolution 191 (1982), S. 289-291 
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    ISSN: 1432-041X
    Keywords: Drosophila ; Imaginal discs ; Cell competition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Imaginal wing discs from late third-instar larvae were gammairradiated to induce clones of rapidly growingMinute − cells in a background of slowly growingMinute cells and culturedin vivo for periods up to 18 days. Clones in discs cultured for 16 to 18 days did not grow significantly larger than clones in uncultured controls, indicating that competition between populations of cells having potentially different mitotic rates does not occur in imaginal discs after their growth is completed.
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    URL: http://dx.doi.org/10.1007/BF00848419
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    Sequential gene activation by ecdysteroids in polytene chromosomes ofDrosophila melanogaster (1982)
    Springer
    Development genes and evolution 191 (1982), S. 103-111 
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    ISSN: 1432-041X
    Keywords: Drosophila ; Polytene Chromosomes ; Ecdysteroids ; Fat Body
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Changes in polytene chromosome 3 L puffing patterns in the fat body ofDrosophila melanogaster larvae and prepupae are compared to those in the salivary gland. While some general features are common to the two tissues, there are differences which reflect their different developmental roles. In vitro experiments with fat body chromosomes show that they have a distinct response to ecdysteroids which is different from that of salivary gland chromosomes, and which does not,in this culture system, reproduce the changes observed in normal development. In short term culture experiments, the fat body chromosomes appear more sensitive to ecdysteroids than the salivary gland chromosomes and, although 20-OH ecdysone is more active than ecdysone in these assays, the possibility is not excluded that ecdysone has a role in normal development as it appears to alter gene activity at physiological levels in these cells.
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    Homologies of positional information in thoracic imaginal discs ofDrosophila melanogaster (1982)
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    Development genes and evolution 191 (1982), S. 293-300 
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    ISSN: 1432-041X
    Keywords: Drosophila ; Imaginal discs ; Positional information ; Homology ; Intercalary regeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The regulative behavior of fragments of the imaginal discs of the wing and first leg was studied when these fragments were combined with fragments of other thoracic imaginal discs. A fragment of the wing disc which does not normally regenerate when cultured could be stimulated to regenerate by combination with certain fragments of the haltere disc. When combined with a haltere disc fragment thought to be homologous by the criteria of morphology and the pattern of homoeotic transformation, such stimulated intercalary regeneration was not observed. Combinations of first and second leg disc fragments showed that a lateral first leg fragment could be stimulated to regenerate medial structures when combined with a medial second leg disc fragment but not when combined with a lateral second leg disc fragment. Combinations of wing and second leg disc fragments showed that one fragment of the second leg disc is capable of stimulating regeneration from a wing disc fragment while another second leg disc fragment fails to stimulate such regeneration. It is suggested that absence of intercalary regeneration in combinations of fragments of different thoracic imaginal discs is a result of homology or identity of the positional information residing in the cells of the fragments. The pattern of correspondence of positional information revealed by this analysis is consistant with the pattern of homology determined by morphological observation and by analysis of the positional specificity of homoeotic transformation among serially homologous appendages. The implications of the existence of homologous positional information in wing and second leg discs which share a common cell lineage early in development are discussed.
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    Gap junctions are non-randomly distributed inDrosophila wing discs (1982)
    Springer
    Development genes and evolution 191 (1982), S. 335-339 
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    ISSN: 1432-041X
    Keywords: Drosophila ; Gap junction ; Wing disc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The distribution of gap junctions in mature larvalDrosophila melanogaster wing discs was analyzed by means of quantitative electron microscopy. Gap junctions are non-randomly distributed in the proximal-distal disc axis and in the apical-basal cell axis of the epithelium. In the epithelial cells, the surface density, number and length of gap junctions are greatest in the apical cell region and distal disc region. The average gap junction surface density is 0.0572 μm−1 and 2.77% of the lateral cell surface is composed of gap junctions. In the adepithelial cells, the gap junction surface density is 0.0005 μm−1 and 0.06% of the cell surface is composed of gap junctions. No gap junctions were observed between epithelial cells and adepithelial cells. The absolute area of gap junctions was estimated in a proximal-distal strip of cells in the disc and is considerably less in the folded regions of the epithelium compared to the flat notum and wing pouch regions. The results are discussed with respect to pattern formation and growth control in imaginal discs.
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    Dicephalic — ADrosophila mutant affecting polarity in follicle organization and embryonic patterning (1982)
    Springer
    Development genes and evolution 191 (1982), S. 28-36 
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    ISSN: 1432-041X
    Keywords: Drosophila ; Polarity ; Maternal effect ; Nurse cells ; Embryogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The mutationdicephalic (dic) affects follicle development and thereby alters the antero-posterior polarity of embryonic patterning. It maps at a single locus (3–46.0±1.0) and can be characterized as a semi-dominant maternal effect mutation with low penetrance. Indic follicles, the 15 nurse cells form two clusters located at opposite poles of the oocyte; the numerical distribution of the nurse cells among the clusters varies from 7:8 to 1:14. Thedic egg shell carries a micropyle (anterior marker) at either pole, but the misshapen respiratory appendages are restricted to one of the two poles in most eggs. The malformed eggs rarely yield larvae and these are always abnormal anteriorly and/or posteriorly. The segment pattern expressed in their cuticle may represent two anterior parts of opposite polarities (double head type), two posterior parts of opposite polarities (double abdomen type, rare) or show uniform polarity. Lability of organization at the cystocyte stage appears as the primary developmental defect of the mutant.
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    A clonal analysis of cell lineage and growth in the male and female genital disc ofDrosophila melanogaster (1982)
    Springer
    Development genes and evolution 191 (1982), S. 42-55 
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    ISSN: 1432-041X
    Keywords: Clonal analysis ; Growth ; Cell lineage ; Genital disc ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary InDrosophila, the terminalia (i.e. internal and external analia and genitalia, except the gonads) are formed by the genital disc. Comparative studies suggested that this disc may have evolved through fusion of the imaginal primordia of the last 3 or 4 abdominal segments. The present report describes the clonal relationships within the complex genital disc. Genetically marked cell clones were induced in male and female embryos and larvae heterozygous for cell marker mutations. 1) Frequencies and sizes of clones suggest that the embryonic disc anlage consists of 14–17 precursor cells: 4–6 for the analia, some 7 for the male genitalia, and 3–4 for the female genitalia. These cells grow exponentially during larval development. 2) In both sexes, the clones were confined to either analia or genitalia, suggesting two separate cell lineages already established at blastoderm. 3) Internal and external genitalia remain in the same compartment at least up to 60 h (end of first instar). 4) A clonal restriction appeared around 84 h (mid second instar), separating a dorsal from a ventral part in the male genitalia. The ventral compartment comprises the ventral part of the lateral plate and clasper, hypandrium, and all internal genitalia. No such boundary was detected in the female. 5) In the female, analia and parovaria originate from the same precursors; another cell lineage forms eighth tergites, vaginal plates, oviduct, receptacle, and spermathecae. 6) In female analia, dorsal and ventral plate share common precursors at least up to 84 h. A medio-lateral boundary may appear at 84 h in the ventral anal plate. No clonal restriction was found in the male analia. 7) At all times, clones could cross between left and right sides of the symmetrical terminalia; they consistently did so via ventral structures. 8) The results are discussed in a phylogenetic context, and we propose that the clonal relations reflect the evolution of the complex genital disc.
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    Maternal effects of zygotic mutants affecting early neurogenesis inDrosophila (1982)
    Springer
    Development genes and evolution 191 (1982), S. 191-201 
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    ISSN: 1432-041X
    Keywords: Neurogenic mutants ; Maternal effects ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The size of the neurogenic region ofDrosophila melanogaster is under the control of several genes of zygotic expression. Lack of function from any of those genes produces an increase of the size of the neurogenic region at the expense of the epidermal anlage. However, differences exist in the extent of neuralisation achieved by each of the genetic loci upon mutation. The present results show that in the case ofN andmam phenotype differences are due to different contributions of maternal gene expression. This could be shown by studying the phenotype which appeared in mutant embryos when the oocytes developed from homozygous mutant precursor cells. Clones of mutant cells were induced in the germ line of females heterozygous for the neurogenic mutationin trans over germ line dependent, dominant female sterile mutations. After removing maternal information the phenotype ofN andmam mutants became identical in both cases. Furthermore maternal information fromN + was found to be necessary for viability of the wildtype.
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    Clonal analysis ofsex-lethal, a gene needed for female sexual development inDrosophila melanogaster (1982)
    Springer
    Development genes and evolution 191 (1982), S. 211-214 
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    ISSN: 1432-041X
    Keywords: Drosophila ; Clonal analysis ; Sex determination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The mutationSxl f , located on the X-chromosome, is a sex-limited recessive lethal that specifically kills 2X; 2A flies while it does not affect X; 2A flies (Cline 1978). We have analyzed the role ofSxl f on sex determination by a clonal analysis of a new spontaneous allele,Sxl fLS . Female embryos and larvae heterozygous forSxl fLS were irradiated at different times of development to generate homozygousSxl fLS clones which were recognized by linked marker mutations. We have studied the phenotype of such clones on sexually dimorphic regions of the fly (foreleg basitarsus, 5th, 6th and 7th tergites, analia and external genitalia). Despite their female (2X; 2A) chromosomal constitution, clones homozygous forSxl fLS differentiated male structures. These results confirm and extend the preliminary report of Cline (1979). They show that the wildtype product ofSxl f is required for female development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848339
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