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  • Drosophila  (42)
  • Springer  (42)
  • Annual Reviews
  • 2005-2009
  • 1990-1994  (42)
  • 1980-1984
  • 1950-1954
  • 2009
  • 1992  (42)
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  • 2005-2009
  • 1990-1994  (42)
  • 1980-1984
  • 1950-1954
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 83 (1992), S. 821-826 
    ISSN: 1432-2242
    Keywords: Drosophila ; Balancers ; Inversions ; Translocations ; Meiosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We used a screen for maternally generated late embryonic lethals as a new method for the isolation of inversions that are suitable for the balancing of mutations in Drosophila hydei. The recovery of several inversions by this method demonstrates that female meiosis in D. hydei apparently differs from meiosis in female D. melanogaster, since in D. hydei the defective chromosomes which are generated by a single crossing-over within a paracentric inversion can be recovered via the egg nucleus. In addition, the classic method of crossingover suppression was used in order to isolate more inversions and to improve the balancing capacities of inversions. We succeeded in constructing chromosomes that allow the balancing of mutations on nearly the whole genome of D. hydei. We discuss here whether or not this method is suited for application to other organisms.
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  • 2
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    Oecologia 92 (1992), S. 183-187 
    ISSN: 1432-1939
    Keywords: Drosophila ; Resource exploitation ; Decaying-herbage breeding ; Host choice
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The Drosophila fauna of a deciduous flood plain forest rich in undergrowth near the river Isar, close to Munich, Germany, was surveyed in summer 1990. Decaying herbage baits (decay artificially induced) were set out to study the exploitation of that resource by Drosophila. Sixteen plant species belonging to several families dominant in the collecting area were tested. All attracted and produced drosophilid flies. Ten Drosophila species utilized decaying plant material as breeding sites; at least eight of the ten are polyphagous. Decaying stalks and leaves of Angelica sylvestris (Apiaceae) were examined in detail. In the case of the most frequent species of Drosophila attracted to A. sylvestris, the number of adults collected did not correlate with the number of flies emerging from the substrate. This was particularly true of D. limbata and D. phalerata. When oviposition and larval development of D. limbata and D. phalerata on A. sylvestris was tested in the laboratory, the number of offspring per female was the same in both species. The difference between these two species of the quinaria group in the exploitation of A. sylvestris in the field is therefore not due to differential suitability of the substrate.
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  • 3
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    Journal of molecular evolution 35 (1992), S. 51-59 
    ISSN: 1432-1432
    Keywords: Drosophila ; Gart locus ; Chironomus tentans ; Purine nucleotide biosynthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The Drosophila Gart locus consists of two genes. One gene encodes three enzymes in the de novo purine nucleotide biosynthesis pathway [glycinamide ribonucleotide synthetase (GARS), aminoimidazole ribonucleotide synthetase (AIRS), and glycinamide ribonucleotide transformylase (GART)]. The second gene lies within an intron of the purine gene and encodes a cuticle protein. To investigate the evolution of the Gart locus, the Chironomus tentans homolog was cloned by screening a genomic DNA library with a polymerase chain reaction product. This study shows that the interesting structural features of this locus conserved in two distant Drosophila species are not found in the Chironomus homolog. These features include the cuticle protein gene nested within an intron and the existence of an alternative transcript to yield a monofunctional enzyme. In addition, the extremely rapid divergence of coding sequence seen for members of the tandemly duplicated AIRS domain in Drosophila is found to be much less rapid in Chironomus.
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  • 4
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    Journal of molecular evolution 34 (1992), S. 130-140 
    ISSN: 1432-1432
    Keywords: Drosophila ; Sophophora ; cDNA-DNA hybridization ; Phylogenetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have performed DNA-DNA hybridization experiments among several species of Drosophila using the evolutionarily conserved portion of the genome representing sequences coding for amino acids of proteins. This was done by using as tracer, radioactively labeled complementary DNA that was reverse transcribed from adult mRNA. We show that this procedure extends phylogenetically the distance over which the technique can be applied to fast-evolving groups such as Drosophila. The major phylogenetic conclusions are (1) the subgenus Sophophora is a monophyletic lineage; (2) within Sophophora the melanogaster subgroup is closer to the obscura group than either group is to the willistoni group; (3) the subgenus Drosophila is complex with most major lineages originating deep in the phylogeny; the subgenus may not be monophyletic; (4) as with most groups classically placed in Drosophila, the Hawaiian Drosophila originate early, supporting the notion that this lineage is older than the extant islands; and (5) the virilis/repleta lineage is monophyletic within Drosophila.
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  • 5
    ISSN: 1432-1432
    Keywords: Drosophila ; per gene ; Threonine-Glycine ; repeat sequence ; melanogaster subgroup phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The Threonine-Glycine (Thr-Gly) region of the period gene (per) in Drosophila was compared in the eight species of the D. melanogaster subgroup. This region can be divided into a diverged variable-length segment which is flanked by more conserved sequences. The number of amino acids encoded in the variable-length region ranges from 40 in D. teissieri to 69 in D. mauritiana. This is similar to the range found within natural populations of D. melanogaster. It was possible to derive a Thr-Gly “allele” of one species from that of another by invoking hypothetical Thr-Gly intermediates. A phylogeny based on the more conserved flanking sequences was produced. The results highlighted some of the problems which are encountered when highly polymorphic genes are used to infer phylogenies of closely related species.
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  • 6
    ISSN: 1420-9071
    Keywords: Aromatic plants ; essential oils ; Drosophila ; insecticides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Effects of the essential oils (EOs) extracted from eleven aromatic plants belonging to the Lamiaceae family (common in the Greek flora) were examined upon three different developmental stages ofDrosophila auraria. All of the EOs examined exhibited insecticidal effects, either by preventing egg hatching, or by causing the death of larvae and adult flies. In several cases, malformation and/or prohibition of puparium formation was also observed.
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  • 7
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    Cellular and molecular life sciences 48 (1992), S. 623-629 
    ISSN: 1420-9071
    Keywords: Drosophila ; heat shock ; stress ; heat shock protein ; gene regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Major alterations in genetic activity have been observed in every organism after exposure to abnormally high temperatures. This phenomenon, called the heat shock response, was discovered in the fruit flyDrosophila. Studies with this organism led to the discovery of the heat shock proteins, whose genes were among the first eukaryotic genes to be cloned. Several of the most important aspects of the regulation of the heat shock response and of the functions of the heat shock proteins have been unraveled inDrosophila.
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  • 8
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    Development genes and evolution 202 (1992), S. 23-35 
    ISSN: 1432-041X
    Keywords: Ecdysteroid ; Imaginal disc ; Drosophila ; Cell line
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have investigated the action of the moulting hormone 20-hydroxy ecdysone (20-HOE) on our leg and wing imaginal disc cell lines. At the morphological level, cells stop dividing and there is some cell death. The remaining cells elongate and aggregate, often producing long processes which form connections between different aggregates. 20-HOE acts within the first one or two days of a passage, at an optimum concentration of 10 ng/ml, this being about 1/100 of the optimum for ecdysone. One cloned wing cell line, C9, has been found to be relatively insensitive to the action of 20-HOE. We have been able to select for resistance to 20-HOE by growing cells in gradually increasing concentrations of hormone followed by passages in hormone-free medium. This has enabled us to isolate a wing cell line C1.8R from its parent cloned line C1.8+. This shows no response to 20-HOE, and cell growth continues even at hormone concentrations as high as 150 ng/ml. We have measured chitin synthesis by the incorporation of radioactive glucosamine into a cell fraction resistant to extensive alkali hydrolysis. The residue was incubated with chitinase, which resulted in a 50% reduction in labelled product. Treatment with 10 ng/ml of 20-HOE dramatically increased chitin synthesis in line C1.8+, but had no effect in the line C1.8R, selected for resistance to hormone.
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  • 9
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    Development genes and evolution 202 (1992), S. 49-60 
    ISSN: 1432-041X
    Keywords: Drosophila ; Delta ; Enhancers ; Suppressors ; Neurogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have screened for dominant enhancers and suppressors of the wing phenotype associated with two Delta alleles: Dl 9P39, an amorphic allele, and Dl FE32, an antimorphic allele. The interactions of some of the modifiers with Delta are due to haplo-insufficient expression of the corresponding genes. Although not explicitly shown for the remaining cases, we assume that haploin-sufficiency is also the basis for the relationships of these genes to Delta, since no allele specific interactions were observed. The modifiers found define 22 genes with pleiotropic expression, which can be classified into two groups: genes required for wing vein pattern formation and for neurogenesis, and genes which are not required for neurogenesis. Among the genes of the first group, Hairless and Star were previously known to participate in neural development. One further modifier was found which may correspond to a new neurogenic gene. The second group of genes is larger and includes already known loci, e.g., Plexate, blistered, plexus, etc, as well as other previously unidentified genes, which function during wing morphogenesis.
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  • 10
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    Development genes and evolution 201 (1992), S. 105-112 
    ISSN: 1432-041X
    Keywords: Drosophila ; Genital disc ; tra-2 ts ; Differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Diplo-X flies homozygous for the transform-er-2 ts (tra-2 ts) mutation develop into females at 16° C, while they develop into males at 29° C (Belote and Baker 1982). By means of this conditional mutation, we have carried out a detailed analysis of the development of the genital disc. Temperature shifts between 16 and 29° C, in both directions, and temperature pulses at 29° C, have been applied during the larval growth of tra-2 ts homozygous diplo-X flies, and the external derivatives of the genital disc have been analysed. Genital discs shifted from 16 to 29° C rapidly lose their capacity to differentiate female genital structures, while they become able to differentiate male genital structures whose inventory is more complete the earlier in larval development the temperature shift is carried out; moreover, duplicated male genital structures were observed. In the shift from 29 to 16° C, the genital disc loses its capacity to differentiate male genital structures, while it becomes able to differentiate female genital structures. The inventory of male structures is smaller, and the inventory of the female structures is more complete, the earlier in larval development the temperature is shifted. No duplicated female or male genital structures were observed in the downshift experiment. With respect to the analia, the shift from 16 to 29° C resulted in the quick formation of pure male anal plates, while in the opposite shift the formation of pure female anal plates occurred gradually. Moreover, the time course for the dorsal and ventral anal plates to show normal female phenotype was different: when the dorsal anal plates were completely normal, it was still possible to find incomplete ventral anal plates. In the pulse experiment at 29° C, the genital disc is able to differentiate both female and male genital structures, although the inventory of the latter ones was not complete. In addition, the capacity of the genital disc to differentiate male genital structures depended on the duration of the temperature pulse. The anal plates were always female, although they showed a reduction in their size, the ventral female anal plate being more affected than the dorsal one. No male anal plates were observed. The results have revealed that the genital disc follows a sequence in its capacity to differentiate female or male adult structures. We suggest that this sequence reflects the sequence of determination events occurring in the genital disc during its larval growth. In addition, results shown here provide evidence for the existence in the female genital primordium of a set of cells capable of giving rise either to female genital structures (ventral vaginal plates) or to male genital structures (hypandrium and penis apparatus). We also present evidence supporting the previous idea of two primordia for the anal plates.
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  • 11
    ISSN: 1432-041X
    Keywords: Muscle ; Salivary glands ; Gut ; Programmed cell death ; Steroid hormones ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In holometabolous insects, the steroid molting hormone 20-OH-ecdysone (ecdysterone) orchestrates the diverse developmental events of metamorphosis, in large part by regulating gene expression. In Drosophila, the Broad Complex (BR-C) is one of the first loci to be induced by ecdysterone at the end of larval life, and is essential for translating the hormonal signal into the behavioral and anatomical events which herald the onset of metamorphosis. BR-C products are believed to act by binding to and modifying the transcriptional activities of other hormone-sensitive genes. In addition to abnormalities of the epidermis, BR-C mutants dying during metamorphosis manifest a syndrome of multiple internal tissue defects which represent a failure of the larval-to-adult transition. We have reported features of central nervous system metamorphosis requiring BR-C function, notably morphogenetic movements and optic lobe organization. In this paper we describe defective development of salivary glands, flight muscles, and gut in BR-C mutants, including: persistence of larval salivary glands; failure of the adult salivary glands to extend into the thorax; abnormalities of midgut transition and of proventriculus structure and location; and absence of dorsal-ventral indirect flight muscles. Some of these abnormalities represent defects in programmed cell death. Distinct patterns of phenotypes were seen in mutants of each of the three lethal complementation groups comprising the BR-C. The patterns of phenotypes suggest overlapping but distinct functions encoded by this complex locus.
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  • 12
    ISSN: 1432-041X
    Keywords: Drosophila ; Imaginal discs ; Pattern formation ; rotund
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary InDrosophila imaginal discs, pattern formation requires the activity of three positional information systems, antero-posterior (A/P), dorso-ventral (D/V) and proximo-distal (P/D). Three genes,Decapentaplegic, Distal-less androtund (rn), involved in pattern formation along the P/D axis have been characterized. Thern gene is required in a sub-distal region, localized at a similar position along the P/D axis in all appendages; it encodes two major transcripts, m1.7 and m5.3, both expressed in the central region of all the major imaginal discs. The present study of these transcripts in severalrn mutant favours m5.3 as encodingrn morphogenetic function in the imaginal discs. The fine characterization of its distribution partitions all major imaginal discs in domains along the P/D axis. The ventral and dorsal discs appear to be similarly but not identically organized: two P/D domains are evident in the wing and haltere discs whilst the leg and antenna discs appear to be composed of at least three. We also show that m5.3 is sex-regulated in the genital disc and thatrn function is required for proper development of a sub-distal structure of the female genitalia. This suggests that the primordia of the female genitalia may be organized in a similar way to the other imaginal discs, and strongly supports the hypothesis thatrn function is specific to pattern formation along the P/D axis and that it may be involved in the establishment or maintenance of this pattern.
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  • 13
    ISSN: 1432-041X
    Keywords: Drosophila ; Pattern formation ; Segment polarity genes ; gooseberry ; Cell interactions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Segment polarity genes define the cell states that are required for proper organization of each metameric unit of the Drosophila embryo. Among these, the gooseberry locus has been shown to be composed of two closely related genes which are expressed in an overlapping single-segment periodicity. We have used specific antibodies raised against the protein product of the gooseberry proximal (gsb-p) gene to determine the spatial distribution of this antigen in wild type embryos, and to monitor the effects of segment polarity mutants on the pattern of the gsb-p protein distribution. We find that the gsb-p protein accumulates beneath each posterior axonal commissure in the progeny of neuroblasts deriving from the epidermal compartments of wingless (wg) and engrailed (en) expression. The results of this analysis support the idea that gsb-p has a specific role in the control of cell fates during neurogenesis, and indicate that en and wg provide critical positional cues to define the domain in which gsbp will be activated. Furthermore, these data suggest that, in order to be expressed in the embryonic CNS, gsb-p may preliminarily require activity of the gooseberry-distal gene in the epidermis.
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  • 14
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    Development genes and evolution 201 (1992), S. 88-94 
    ISSN: 1432-041X
    Keywords: Fate map ; Drosophila ; Flight muscle ; Mosaics ; Cell lineage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A blastoderm fate map has been prepared for Drosophila, using mosaics of a temperature-sensitive mutation, shibire (shi). The mutation can cause abnormal flight muscle morphology, inducible only by a short heat pulse in early metamorphosis. Thus muscle lineage and development are unperturbed until the heat pulse in the early pupa. The developmental focus of the shi muscle phenotype maps to the ventral thorax at the expected site of thoracic mesoderm, and probably indicates the blastoderm progenitors of the adult flight muscle. The fate map provides greater detail than previously available for the dorsolongitudinal fibers (DLM) of flight muscle, showing wide separation of the fibers of flight muscle. DLM fibers a and b map close together, and far anterior to fibers e and f, which also map together. On a fate map, common developmental focus indicates a common blastoderm origin. Thus, the observed pattern for DLM fibers suggests that the blastoderm progenitors for each of these syncytial fiber pairs (a, b; e, f) include only one or two cells. It follows that there is usually a single genotype within each fiber pair (a, b; e, f), and that this genotype is directly reflected in the fiber phenotype. In a large number of cases, DLM fibers a and b differ in phenotype from other DLM fibers, in parallel with their other differences (e.g., timing of development in pupa, innervation, motor activity). The separation of fate map locations of the developmental focus for DLM fibers within mesoderm suggests that specific fibers of flight muscle may, in normal development, originate in all three thoracic mesodermal parasegments.
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  • 15
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    Development genes and evolution 201 (1992), S. 194-220 
    ISSN: 1432-041X
    Keywords: Drosophila ; Enhancer trap lines ; Embryogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Embryos of 171 Drosophila lines carrying a P-lacZ insertion on the second or third chromosome were analyzed regarding their pattern of lacZ expression. All lines were selected from a larger screen of about 4000 lines (Bier et al. 1989). Tissue specificity and time of onset of lacZ expression was documented for each line. Thereby, a comprehensive list of markers for the various tissue and cell types of the Drosophila embryo could be assembled. With the help of several P-lacZ lines the development of a number of structures was studied which so far had been described only insufficiently or not at all. In particular, the embryonic origin and early development of the oenocytes, imaginal discs, histoblasts, fat body, dorsal vessel, and perineurial cells was analyzed. Several previously unknown cell types associated with the dorsal vessel, trachea, and epidermis were discovered. By combining data regarding the origin of the different mesodermally derived organs it was possible to generate in some detail a fate map of the mesoderm of the stage 11 Drosophila embryo.
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  • 16
    ISSN: 1432-041X
    Keywords: Drosophila ; Homeotic gene regulation ; Antennapedia ; Development ; β-galactosidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In order to study the regulation of spatial and temporal expression of the homeotic gene Antennapedia (Antp) in Drosophila melanogaster, we have constructed fusion genes which contain Antp sequences linked to the reporter gene lac Z of Escherichia coli. In one case of P-element transformation, a fusion gene construct integrated into the endogenous Antp gene close to one of the two promoters (P1). The spatial expression from the reporter gene in this transformant line, as analysed by the detection of β-galactosidase activity, was found to exactly mimic the normal expression from the P1 promoter of the Antp gene. We have used this unique transformant as a tool for studying the expression of the P1 promoter in embryonic, larval and adult development. Parallel lines transformed with the same fusion gene construct did not confer a correct P1 pattern of expression. The position in the genome was, therefore, crucial for the expression pattern of the reporter gene. Experiments aiming at the detection of autoregulatory control of Antp gene expression were designed. The results did not, however, support models of positive or negative autoregulation of P1 expression by Amp protein.
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  • 17
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    Development genes and evolution 201 (1992), S. 364-375 
    ISSN: 1432-041X
    Keywords: Drosophila ; Tissue culture ; In vitro ; Invertebrate embryogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have devised techniques to culture whole, dissected embryos of Drosophila melanogaster. We examine multiple aspects of the morphological and physiological development of the epidermis, musculature, nervous system, and internal organs in this cultured preparation, and show that in vitro development closely parallels normal embryogenesis. These techniques permit a wide range of experimental manipulations during embryogenesis and allow us to extend observations through late embryonic stages, after cuticle deposition. Applications of this technique are presented.
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  • 18
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    Development genes and evolution 201 (1992), S. 120-123 
    ISSN: 1432-041X
    Keywords: Integrin ; Drosophila ; In vitro ; Imaginal disc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Drosophila imaginal disc cell lines show a characteristic pattern of aggregation in culture, which appears to be due to cell-cell rather than cell-substrate interactions. We have examined the distribution of PS integrins in wing and leg cell lines, and find that these integrin homologues are expressed preferentially in aggregates. Cell sheets, small cell clumps and chains of cells express antigen at points of cell-cell contact only.
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  • 19
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    Development genes and evolution 201 (1992), S. 1-11 
    ISSN: 1432-041X
    Keywords: Drosophila ; Neurogenesis ; Signals ; Delta ; Notch
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ectodermal germ layer of Drosophila melanogaster gives rise to two major cell lineages, the neural and the epidermal. Progenitor cells for each of these lineages arise from groups of cells, whose elements must decide between taking on either fate. Commitment of the progenitor cells to one of the developmental fates implies two factors. One is intrinsic to the ectodermal cells and determines a propensity to take on neural fate; this factor is probably represented by the products of the so-called proneural genes, which are differentially distributed throughout the ectoderm. The other factor in the cells' decision to adopt one of the two alternative fates is intercellular communication, which is mediated by the products of the so-called neurogenic genes. Two types of interactions, one inhibiting and the other stimulating neural development, have been inferred. We discuss here the assumed role of various neurogenic genes, in particular Notch and Delta, in these processes.
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  • 20
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    Behavior genetics 22 (1992), S. 469-487 
    ISSN: 1573-3297
    Keywords: courtship ; pheromones ; Drosophila ; apterous ; juvenile hormone ; reproductive development ; sexual behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Theapterous (ap) gene ofDrosophila melanogaster exhibits extreme pleiotrophy: its functioning is essential for life, normal wing structure, juvenile hormone production, female fertility, and normal development of female sexual receptivity. Four mutantap alleles (ap 4,ap 56f,ap c, andap blt) were characterized for three additional phenotypes: male mating success, courtship behavior, and immature male sex appeal (the ability of males to stimulate homosexual cortship). Mating success with mature wild-type virgin females is reduced in males mutant for theap gene, the extreme case beingap 4/ap 4 males, which are behaviorally sterile. Inap mutants, nonwing courtship elements are qualitatively like those ofap +/ap + males. However, the mean rate of nonwing courtship directed toward virgin wild-type females (i.e., the mean temporal frequency of these displays) is reduced in males homozygous forap 4,ap 56f, orap c alleles. In contrast, theap blt allele makes for wild-type rates of nonwing courtship. Immature male sex appeal persists for at least 3 days in males homozygous forap c and, to a lesser extent, inap 56f orap 4 homozygotes;ap blt/ap blt and wild-type males lose immature male sex appeal after 1 day. All three male phenotypes map to theap locus, which is therefore essential for the development of normal levels of male courtship and male mating success and for the timely loss of immature male sex appeal. For each phenotype,ap + is dominant toap alleles making for behavioral abnormalities, with a single exception (for rate of nonwing courtship,ap +/ap c was low). For mating success and frequency of nonwing courtship, each allele pair exhibits at least partial complementation, except forap 4 andap 56f, which fail to complement. For immature male sex appeal,ap c,ap 4, andap 56f fall into the same complementation group. Juvenile hormone production is not correlated with effects on male reproductive behavior.
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  • 21
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    Behavior genetics 22 (1992), S. 557-573 
    ISSN: 1573-3297
    Keywords: Drosophila ; biometrical analysis ; behavior genetics ; genetic analysis ; ss a ; deletion mapping
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract The homeotic mutationspineless-aristapedia (ss a ) transforms the aristae into second tarsi. Flies with aSS a phenotype also show extremely positive geotaxis as measured in a Hirsch-type geotaxis maze. Other antennal mutants and flies with their aristae amputated do not show such extreme positive geotaxis. Deletion analysis has comapped the geotaxis effect withSS a in band 89C on the third chromosome. Finally, a biometrical analysis has detected additional genes on the X chromosome that also affects geotaxis.
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  • 22
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    Genetica 86 (1992), S. 37-46 
    ISSN: 1573-6857
    Keywords: Mariner ; Drosophila ; molecular evolution ; transposable element
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The population biology and molecular evolution of the transposable element mariner has been studied in the eight species of the melanogaster subgroup of the Drosophila subgenus Sophophora. The element occurs in D. simulans, D. mauritiana, D. sechellia, D. teissieri, and D. yakuba, but is not found in D. melanogaster, D. erecta, or D. orena. Sequence comparisons suggest that the mariner element was present in the ancestor of the species subgroup and was lost in some of the lineages. Most species contain both active and inactive mariner elements. A deletion of most of the 3′ end characterizes many elements in D. teissieri, but in other species the inactive elements differ from active ones only by simple nucleotide substitutions or small additions/deletions. Active mariner elements from all species are quite similar in nucleotide sequence, although there are some-species-specific differences. Many, but not all, of the inactive elements are also quite closely related. The genome of D. mauritiana contains 20–30 copies of mariner, that of D. simulans 0–10, and that of D. sechellia only two copies (at fixed positions in the genome). The mariner situation in D. sechellia may reflect a reduced effective population size owing to the restricted geographical range of this species and its ecological specialization to the fruit of Morinda citrifolia.
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  • 23
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    Evolutionary ecology 6 (1992), S. 342-351 
    ISSN: 1573-8477
    Keywords: Drosophila ; polymorphism ; aggregation ; ephemeral patches ; soft selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Many models have been proposed in which environmental heterogeneity promotes genetic diversity. Such models describe the situation where different phenotypes have different fitness values in different types of patch and are the genetic equivalent of the traditional resource partitioning models in ecology which allow the coexistence of species. Here we construct a different type of cellular model in which polymorphisms in populations ofDrosophila can be maintained without traditional resource partitioning. Parameter values taken from laboratory and field observations represent fungal breedingDrosophila. Some stochasticity is used in the description of the migration between patches. In the model space is divided into a uniform matrix of cells each of which has the potential to contain an ephemeral resource item (fungal fruiting body). Square arenas of up to 400 cells were used. Genotypes arrive at a fresh site, breed (Hardy-Weinberg equilibrium) and lay eggs. The eggs hatch and the larvae compete using the Hassell-Comins competition equations, as if they were three different species. Adult emergents all migrate to an adjacent cell. The aggregation patterns observed in nature are produced using an ‘attraction probability’ where each fly has a chance of moving to the currently most densely populated adjacent patch. This ‘black box’ description of migration produces distribution patterns which are indistinguishable from those seen in wild populations of fungal breedingDrosophila. Results show that the ‘attraction probability’ is the key factor in the maintenance of polymorphism and that even when the competitive advantage of the superior genotype is very great, polymorphisms can be maintained.
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  • 24
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    Biochemical genetics 30 (1992), S. 77-83 
    ISSN: 1573-4927
    Keywords: acetylcholinesterase ; insecticide ; resistance ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Selection of field populations originating from several countries allowed us to isolate 13 strains ofDrosophila melanogaster resistant to parathion.In vitro studies of acetylcholinesterase inhibition by paraoxon have been carried out on purified enzymes: most of the resistant strains harbor an altered acetylcholinesterase. Enzymes with higher resistance levels have been characterized with respect to their cross-resistance toward several insecticides. The patterns obtained have permitted us to group them and to delineate four categories. The existence of four distinct types of protein suggests that several mutations of acetylcholinesterase are responsible for insecticide resistance inDrosophila.
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  • 25
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    Biochemical genetics 30 (1992), S. 159-168 
    ISSN: 1573-4927
    Keywords: Drosophila ; indirect flight muscle ; tropomyosin ; polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We describe polymorphism in aDrosophila indirect flight muscle-specific tropomyosin isozyme, named TnH-34. Three variants of this protein differ in their mobilities as determined by 1-D and 2-D SDS-PAGE. Meiotic mapping places the polymorphism close to, if not within, the structural gene encoding this tropomyosin isozyme. The most likely site of the mutations is within a single C-terminal exon. Flight-testing of different genotypes reveals that this variation in TnH-34 does not affect flight ability. These results suggest that some sequence variation may be tolerated in this section of the protein and correlate with the variability of this protein in different insect species.
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  • 26
    ISSN: 1573-4927
    Keywords: Drosophila ; glycerol-3-phosphate dehydrogenase ; restriction map ; duplication ; enzyme activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Restriction site variation in a 25-kb region including thesn-glycerol-3-phosphate dehydrogenase (Gpdh) locus has been assessed in 29 single femaleD. melanogaster lines from the Cardwell (Australia, QLD) population. TheGpdh locus was duplicated in about one-third of the lines, although the duplication was incomplete and lacked exons 1 and 2. There was no restriction site variation in the duplicated region. Three insertions were found in the gene region but only one affected GPDH activity. The lines with the duplication had higher levels of GPDH activity and protein amount than did nonduplicated lines. This effect was also observed in lines extracted from two other Australian populations. The duplication is shown to have a similar structure in each population investigated and is also present in populations from China and Africa. It is suggested that the effect of the duplication on GPDH activity, which might be due to structural factors affecting transcription at theGpdh locus, could account for the worldwide distribution of the duplication.
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  • 27
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    Biochemical genetics 30 (1992), S. 515-527 
    ISSN: 1573-4927
    Keywords: glutathioneS-transferase ; Drosophila ; cellular detoxification ; pesticide resistance ; insect metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We have isolated aDrosophila gene,DmGST-2, that encodes glutathioneS-transferase, a homo- or heterodimeric enzyme thought to be involved in detoxification of xenobiotics, including known carcinogens. The encoded protein has a primary sequence that is more similar to mammalian placental and nematode GSTs than that of a previously describedDrosophila GST gene, herein referred to asDmGST-1. We provide a physical map of the gene and show that it specifies at least two mRNAs, measuring 1.9 and 1.6 kb, which differ only in the lengths of their 3′ untranslated regions. Both of the mRNAs are present during all developmental stages.In situ hybridization of theDmGST-2 gene to larval polytene chromosomes places it within the 53F subdivision of chromosome 2, and Southern blotting to chromosomal DNA indicates that the gene has no close relatives within theDrosophila genome. Our results make possible molecular genetic approaches for further elaborating the function of glutathioneS-transferases in insect development and physiology, in the metabolism of plant toxins, and in conferring insecticide resistance.
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  • 28
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    Biochemical genetics 30 (1992), S. 159-168 
    ISSN: 1573-4927
    Keywords: Drosophila ; indirect flight muscle ; tropomyosin ; polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We describe polymorphism in aDrosophila indirect flight muscle-specific tropomyosin isozyme, named TnH-34. Three variants of this protein differ in their mobilities as determined by 1-D and 2-D SDS-PAGE. Meiotic mapping places the polymorphism close to, if not within, the structural gene encoding this tropomyosin isozyme. The most likely site of the mutations is within a single C-terminal exon. Flight-testing of different genotypes reveals that this variation in TnH-34 does not affect flight ability. These results suggest that some sequence variation may be tolerated in this section of the protein and correlate with the variability of this protein in different insect species.
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  • 29
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    Biochemical genetics 30 (1992), S. 305-315 
    ISSN: 1573-4927
    Keywords: Drosophila ; diaphorase ; purification ; kinetics ; immunochemical characteristics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Diaphorase-1 and diaphorase-2 were isolated from twoDrosophila species,D. virilis andD. melanogaster, and purified by gel filtration, affinity chromatography, immunoaffinity chromatography, and ion-exchange chromatography. The molecular weights of both enzymes were the same in each species. The molecular weight of diaphorase-1 was the same under both denaturating and nondenaturating conditions, close to 60,000, indicating a monomeric structure. Sodium dodecyl sulfate (SDS) electrophoresis of the purified diaphorase-2 revealed the presence of a single protein band of 55,000 Da, while the molecular weight of the native enzyme was found to be 67,000. The two diaphorases were further characterized by their pH optima, isoelectric points, and kinetic parameters, and antibodies were raised in rabbits against the purified enzymes fromD. virilis. The antibodies showed no cross-reactions but recognized the corresponding diaphorases inD. melanogaster andD. novamexicana as well asD. virilis. The data obtained confirmed the hypothesis of an independent genetic control of diaphorase-1 and diaphorase-2 inDrosophila.
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  • 30
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    Biochemical genetics 30 (1992), S. 305-315 
    ISSN: 1573-4927
    Keywords: Drosophila ; diaphorase ; purification ; kinetics ; immunochemical characteristics
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Diaphorase-1 and diaphorase-2 were isolated from twoDrosophila species,D. virilis andD. melanogaster, and purified by gel filtration, affinity chromatography, immunoaffinity chromatography, and ion-exchange chromatography. The molecular weights of both enzymes were the same in each species. The molecular weight of diaphorase-1 was the same under both denaturating and nondenaturating conditions, close to 60,000, indicating a monomeric structure. Sodium dodecyl sulfate (SDS) electrophoresis of the purified diaphorase-2 revealed the presence of a single protein band of 55,000 Da, while the molecular weight of the native enzyme was found to be 67,000. The two diaphorases were further characterized by their pH optima, isoelectric points, and kinetic parameters, and antibodies were raised in rabbits against the purified enzymes fromD. virilis. The antibodies showed no cross-reactions but recognized the corresponding diaphorases inD. melanogaster andD. novamexicana as well asD. virilis. The data obtained confirmed the hypothesis of an independent genetic control of diaphorase-1 and diaphorase-2 inDrosophila.
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  • 31
    ISSN: 1573-4927
    Keywords: Drosophila ; glycerol-3-phosphate dehydrogenase ; restriction map ; duplication ; enzyme activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Restriction site variation in a 25-kb region including thesn-glycerol-3-phosphate dehydrogenase (Gpdh) locus has been assessed in 29 single femaleD. melanogaster lines from the Cardwell (Australia, QLD) population. TheGpdh locus was duplicated in about one-third of the lines, although the duplication was incomplete and lacked exons 1 and 2. There was no restriction site variation in the duplicated region. Three insertions were found in the gene region but only one affected GPDH activity. The lines with the duplication had higher levels of GPDH activity and protein amount than did nonduplicated lines. This effect was also observed in lines extracted from two other Australian populations. The duplication is shown to have a similar structure in each population investigated and is also present in populations from China and Africa. It is suggested that the effect of the duplication on GPDH activity, which might be due to structural factors affecting transcription at theGpdh locus, could account for the worldwide distribution of the duplication.
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  • 32
    ISSN: 1617-4623
    Keywords: Drosophila ; Muscle proteins ; Paramyosin ; Leucine zippers ; Differential polyadenylation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Several cDNA clones encoding the complete Drosophila paramyosin sequence, including two potential polyadenylation sites, have been obtained. Southern analysis and in situ hybridization to polytene chromosomes indicate that in Drosophila the paramyosin gene is single copy, located on the left arm of the third chromosome at region 66D14. Northern analyses show predominantly two different RNAs which are the products of the choice between the two alternative polyadenylation sites. The two species begin to be synthesized around 10 h of development when embryonic muscles are formed, expression peaking at the end of embryogenesis. The protein is first expressed at germ band shortening in association with muscle precursor cells. A second maximum of paramyosin RNA expression occurs at late pupal stages when the higher molecular weight form becomes more abundant. In young adults this species becomes the main transcript detected. The 102 kDa polypeptide sequence is highly similar to that of Caenorhabditis elegans paramyosin. The protein has a central α-helical coiled-coil rod, organized in 29 groups of four typical seven-residue repeats and flanked by two short non-α-helical regions. Several leucine zippers are located on the hydrophobic face of the α-helix in paramyosin which, together with disulfide bonds between cysteines, are probably involved in the stabilization of the dimer. The structural and functional properties of Drosophila paramyosin deduced from the sequence are compared with those of known invertebrate myosins and paramyosins.
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  • 33
    ISSN: 1617-4623
    Keywords: Antibacterial ; Digestion ; Drosophila ; Gene family ; Lysozyme
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary As part of a study of the genes involved in antibacterial defense in Drosophila melanogaster, we have isolated genomic clones harboring a family of chicken-type lysozyme genes, using a lepidopteran lysozyme cDNA as probe. The locus was mapped to the cytological location 61F1-4 on the third chromosome and two of the genes at this locus, LysD and LysP, were analyzed in detail. In contrast to the bacteria-induced lysozymes in the hemolymph of many insects, the transcription levels of both Drosophila genes decrease after bacterial injections into the hemocoel. Apparently, these gene products, like the specifically adapted lysozymes in mammalian foregut fermenters, have been recruited for the digestion of bacteria present in fermenting food. The LysD gene is expressed in an anterior section of the midgut during all feeding stages of development in both larvae and adults. The LysP gene is only active in the adult where it is expressed in the salivary glands. The transcription units for both genes are very compact and they lack introns. Lysozyme D is unusual in that it is predicted to have an acidic isoelectric point whereas lysozyme P appears to be a typical basic lysozyme.
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  • 34
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    Molecular genetics and genomics 235 (1992), S. 441-449 
    ISSN: 1617-4623
    Keywords: Drosophila ; Gene regulation ; Transcription ; Transposable element
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Two spontaneous mutations of rudimentary, the gene encoding the first steps of de novo pyrimidine biosynthesis in Drosophila, are suppressed by mutant alleles of the suppressor of Hairy-wing locus. This interaction differs from typical su(Hw) suppression in that neither rudimentary allele is associated with an insertion of the gypsy retrotransposon. One allele, r sP1, appears to be a point mutation. Adult r sP1 homozygous females accumulate substantially less 7.3 kb rudimentary transcript than do wild-type females. The other allele, r sP2, is an insertion of an mdg3 retrotransposon in the sixth exon of rudimentary and in the opposite transcriptional orientation. This insertion divides the rudimentary locus into two separate, yet functional, transcription units by truncating transcription from the rudimentary promoter and promoting transcription of downstream rudimentary sequences. Phenotypic suppression of both r sP1 and r sP2 by mutant alleles of the suppressor of Hairy-wing locus correlates with enhanced levels of the r sP1 and r sP2 transcripts.
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  • 35
    ISSN: 1573-6857
    Keywords: Drosophila ; transposons ; mobility ; cultured cells
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    Topics: Biology
    Notes: Abstract The genomic distribution and the number of elements of eleven transposon families have been compared by the Southern technique between permanent cultured cells, larval salivary glands and the brains and whole flies of an inbred Drosophila line (inb-c) from which the cells were established. In cultured cells, changes in restriction patterns consistent with various types of rearrangements such as amplification, transposition and excision of the elements of copia, 1731, 412, 297 and mdg-4 transposon families are detected whereas B 104, G and blood elements appear stable. In previous reports these rearrangements were not detected among individuals of the inb-c line or among samples of somatic tissues, or in samples spanning years of maintenance of cultured cells. Hence, we believe that they have been induced de novo during the passage to the cell culture.
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  • 36
    ISSN: 1573-6857
    Keywords: Drosophila ; transposons ; mobility ; inbreeding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The stability of the elements of eleven transposon families (412, B 104, blood, 297, 1731, G, copia, mdg 4, hobo, jockey and I) has been compared by the Southern technique among individuals of a Drosophila line that has been subjected to 30 generations of sister sib matings. The 412, B104, blood, 297, 1731 and G elements appear stable. Heterochromatic copia and hobo elements and euchromatic I elements appear highly polymorphic. In addition, copia, mdg 4, jockey and I elements undergo an instability resulting in significant variations in relative intensity among autoradiographic bands. The extent of the polymorphisms detected strongly suggests de novo rearrangements of transposable elements.
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  • 37
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    Genetica 87 (1992), S. 1-6 
    ISSN: 1573-6857
    Keywords: Temperature ; splicing mechanism ; mammals ; Drosophila ; turtles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sex determination and differentiation are inherently fascinating to both layperson and geneticist. Major advances have accelerated interest in the molecular genetic events mediating these processes in nematodes, flies, mice and humans. Far less attention has been paid to those organisms, particularly reptiles, where sex is determined by environmental cues. However, recent experimental evidence suggests that the two modes of sex determination may not only share common genetic elements, but may also be regulated by similar mechanisms. We argue that the ability to manipulate sex by temperature provides a particularly suitable model for exploring the molecular basis of this fundamental biological process.
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  • 38
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    Genetica 86 (1992), S. 67-84 
    ISSN: 1573-6857
    Keywords: Drosophila ; population genetics ; transposable elements
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This paper is an attempt to bring together the various, dispersed data published in the literature on insertion polymorphism of transposable elements from various kinds of populations (natural populations, laboratory strains, isofemale and inbred lines). Although the results deal mainly with Drosophila, data on other organisms have been incorporated when necessary to illustrate the discussion. The data pertinent to the regions of insertion, the rates of transposition and excision, the copy number regulation, and the degree of heterozygosity were analysed in order to be confronted with the speculations made with various theoretical models of population biology of transposable elements. The parameters of these models are very sensitive to the values of the transposable element characteristics estimated on populations, and according to the difficulties of these estimations (population not at equilibrium, particular mutations used to estimate the transposition and excision rates, trouble with the in situ technique used to localize the insertions, undesired mobilization of TEs in crosses, spontaneous genome resetting, environmental effects, etc.) it cannot be decided accurately which model better accounts for the population dynamics of these TEs. Tendencies, however, emerge in Drosophila: the copia element shows evidence for deficiency of insertions on the X chromosomes, a result consistent with selection against mutational effects of copia insertions; the P element repartition does not significantly deviate from the neutral assumption, in spite of a systematic copy number of insertions higher on the X than on the autosomes. Data on other elements support either the neutral model of TE containment, neither of the two models, or both. Prudence in conclusion should then be de rigueur when dealing with such kind of data. Finally the potential roles of TEs in population adaptation and evalution are discussed.
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  • 39
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    Journal of comparative physiology 162 (1992), S. 203-208 
    ISSN: 1432-136X
    Keywords: Triacylglycerols ; Glycogen ; Reproductive diapause ; Overwintering ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Temperate species of the Drosophila melanogaster group enter reproductive diapause for overwintering in response to short daylength. During the prediapause period they accumulate triacylglycerols, but not glycogen, as energy resources. The capacity for storing triacylglycerols differs between species, and appears to be closely correlated with diapause and cold-hardiness; cool-temperate species, such as those of the auraria species complex, which enter a deep diapause and are highly cold-hardy, accumulate larger quantities of triacylglycerols than warm-temperate species, such as D. rufa and D. lutescens, which enter a weak diapause and are less cold-hardy. Among the cool-temperate spcies, D. subauraria occurs at a higher latitude and has the greatest capacity for accumulating triacylglycerols. A subtropical species, D. takahashii, which has no diapause in nature and is not cold-hardy, is unable to store the same quantities of triacylglycerols as temperate species.
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  • 40
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    Journal of comparative physiology 162 (1992), S. 278-283 
    ISSN: 1432-136X
    Keywords: Biological oscillator ; Deuterium ; Drosophila ; Heart rate ; Temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A non-intrusive optical technique has been developed to monitor heartbeat in late third-instar Drosophila larvae. Heartbeat in this insect is an oscillation that is not temperature compensated. Deuterium oxide lengthens the period of a number of high and low frequency oscillators and clocks in a variety of organisms. To determine whether deuterium affects heart rate, flies were raised on proteated and deuterated media and their heartbeat was monitored at four temperatures ranging from 18 to 33°C. The rate of heartbeat increased linearly with increasing temperature, and decreased with increasing concentrations of deuterium. There was a significant interaction between temperature and deuterium: the higher the concentration of deuterium oxide the less temperature-sensitive was the heart rate. Raising temperatures also increased the amount of “noise” in the rhythm: signal-to-noise ratio, which characterizes the amount of power in a rhythmic signal, decreased with increasing temperatures. Deuterium oxide had no effect on signal-to-noise ratio.
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  • 41
    ISSN: 1617-4623
    Keywords: Dosage compensation ; LSPI-α ; L12 ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The X-linked geneLSPI-α ofDrosophila melanogaster, expressed in the third larval instar, does not exhibit dosage compensation at its normal locus but does compensate when it is relocated to ectopic sites on the X chromosome. A transcription unit designatedL12, which is active in the second larval instar and capable of encoding a putative protein of 28.5 kDa, lies immediately downstream fromLSPI-α. We have determined thatL12 is dosage compensated by measuring the steady-state level of its transcript in male and female larvae. The difference in response of these two adjacent genes should be taken into consideration when models of the mechanism of dosage compensation are formulated.
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  • 42
    ISSN: 1617-4623
    Keywords: Phosphoglycerate kinase ; Drosophila ; Nucleotide sequence ; Glycolysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The gene that encodes phosphoglycerate kinase in Drosophila melanogaster (Pgk) has been isolated and characterized. There is a single copy of Pgk in the Drosophila genome located at cytogenetic position 23A1-2. Transcripts of Pgk are 1.6 kb long and are found during development with a profile similar to the expression pattern of other genes of the glycolytic pathway. There are substantial amounts of maternal transcript in early embryos which decline in abundance until mid-embryogenesis when transcript levels increase; levels remain high, during larval stages, fall during pupariation and rise again at emergence. The nucleotide sequence of the Pgk gene reveals two small introns, one of which is at a position identical to the site of an intron found in Pgk genes from other organisms. The Pgk gene has no TATA box in the region of transcription initiation and has multiple transcription initiation sites that are closely spaced within 110 nucleotides of the translation start site.
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