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  • Drosophila  (53)
  • Springer  (53)
  • American Association for the Advancement of Science
  • 2015-2019
  • 1985-1989  (31)
  • 1980-1984  (22)
  • 1986  (31)
  • 1980  (22)
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  • 2015-2019
  • 1985-1989  (31)
  • 1980-1984  (22)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular evolution 16 (1980), S. 37-46 
    ISSN: 1432-1432
    Keywords: Evolution ; Drosophila ; Temperature ; Mitochondrial enzymes ; Kinetic properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The evolutionary behavior of two mitochondrial enzymes (L-glycerol 3-phosphate:cytochrome c oxidoreductase E.C.1.1.1.95,αGPO, and L-malate: NAD+ oxidoreductase, E.C.1.1.1.37, m-MDH) obtained from several temperate and tropicalDrosophila species was examined by comparing their catalytic properties, which related to temperature (Km-Ea-Q10-Thermostability). MitochondrialαGPO or m-MDH obtained either from temperate or from tropical species was found to exhibit similar catalytic properties while for both cytosolic enzymes, theαGPDH and s-MDH, Km patterns were similar among species from the same thermal habitat and different between thermal habitats. In combination with other observations reported in the literature these facts support the view that the function, and probably the structure, of mitochondrial enzymes are better conserved in evolution than those of the corresponding enzymes found in the cytosol. It is proposed that the relative invariance of the mitochondrial enzymes structure is probably linked to a necessary relative invariance of molecular interactions inside the mitochondrion.
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  • 2
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    Journal of molecular evolution 24 (1986), S. 83-88 
    ISSN: 1432-1432
    Keywords: Transposons ; Polymorphism ; Drosophila ; Southern technique
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The genomic distributions of the copia, 297, 412, mdg 1, and B 104 transposable elements have been compared by the Southern technique among two Oregon R and four Canton SDrosophila laboratory lines that have been maintained separately for defined periods of a few years. The heterogeneity of the autoradiographic patterns suggests that multiple transposition events have occurred during the time of separation. The hypothesis that transposition could be induced by, variations of environmental parameters is discussed.
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  • 3
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    Development genes and evolution 188 (1980), S. 55-63 
    ISSN: 1432-041X
    Keywords: Drosophila ; Compound eye ; shibire ts ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have analysed the effect of temperature on both developing and adult eye cell clones homozygous forshi ST139, a temperature-sensitive mutant ofDrosophila melanogaster. The mutant gene, autonomous in its cellular expression, causes structural modifications of ommatidial cells when adult clones of cells are exposed to the restrictive temperature (29°C) for several days. However, the mutant phenotype reverses to normal within 4 days at the permissive temperature (20°C). The results of pulse, shift-up and shift-down experiments show that the temperaturesensitive period for developing compound eye cells is from the late second instar up to the early pupa. Cytodifferentiation of compound eye cells is blocked by restrictive temperature treatment during this period, whereas cell proliferation does not seem to be directly affected. These results are discussed with regard to the other known aspects of the phenotype observed in mutant individuals.
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  • 4
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    Development genes and evolution 195 (1986), S. 359-377 
    ISSN: 1432-041X
    Keywords: Drosophila ; Blastoderm fate map ; Head segmentation ; Larval cuticle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Embryos of Drosophila melanogaster were irradiated in the presumptive head region with a UV-laser microbeam of 20 μm diameter at two developmental stages, the cellular blastoderm and the extended germ band. The ensuing defects were scored in the cuticle pattern of the head of the first-instar larva, which is described in detail in this paper. The defects caused by irradiating germ band embryos when morphologically recognisable lobes appear in the head region were used to establish the segmental origin of various head structures. This information enabled us to translate the spatial distribution of blastoderm defects into a fate map of segment anlagen. The gnathal segments derive from a region of the blastoderm between 60% and 70% egg length (EL) dorsally and 60% and 80% ventrally. The area anterior to the mandibular anlage and posterior to the stomodaeum is occupied by the small anlagen of the intercalary and antennal segments ventrally and dorsally, respectively. The labrum, which originates from a paired anlage dorsally at 90% EL, is separated from the remaining head segments by an area for which we did not observe cuticle defects following blastoderm irradiation, presumably because those cells give rise to the brain. The dorsal and lateral parts of the cephalo-pharyngeal skeleton appear to be the only cuticle derivatives of the non-segmental acron. These structures derive from a dorso-lateral area just behind the putative brain anlage and may overlap the latter. In addition to the segment anlagen, the regions of the presumptive dorsal pouch, anterior lobe and post-oral epithelium, whose morphogenetic movements during head involution result in the characteristic acephalic appearance of the larva, have been projected onto the blastoderm fate map. The results suggest that initially the head of the Drosophila embryo does not differ substantially from the generalised insect head as judged by comparison of fate map and segmental organisation.
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  • 5
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    Development genes and evolution 195 (1986), S. 489-498 
    ISSN: 1432-041X
    Keywords: Pole cells and midgut progenitors ; Cell lineages ; Embryogenesis ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In this paper experiments concerning some aspects of the development of pole cells and midgut progenitors in Drosophila are reported. Cells were labelled by injecting horseradish-peroxidase (HRP) in embryos before pole bud formation and transplanted at different stages into unlabelled embryos, where the transplanted cells developed together with the unlabelled cells of the host. The hosts were then fixed and stained at different ages in order to demonstrate the presence of HRP in the progenies of transplanted cells. The main conlusions of the study are as follows. The gonads are the only organ to the formation of which pole cells normally contribute; those pole cells which do not participate in the formation of the gonads are finally eliminated or degenerate. Since the number of primordial germ cells in the gonads is the same irrespective of the number of pole cells present in the embryo, an (unknown) mechanism must exist regulating the final number of pole cells in each of the gonads. After their formation and before reaching the gonads, pole cells have been found to divide only up to two times. With respect to the midgut progenitors, the cells of both anlagen have been found to be committed to develop into midgut, although they behave as equivalent in that they do not apparently distinguish between the anterior and posterior anlage. Midgut progenitors have been found to divide a maximum of three times and to produce two different types of cells, epithelial cells of the midgut wall and spindle-like cells located internally in the gut.
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  • 6
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    Cellular and molecular life sciences 42 (1986), S. 191-192 
    ISSN: 1420-9071
    Keywords: Drosophila ; enzyme ; sn-glycerol-3-phosphate ; dehydrogenase ; dominance ; trans, regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A regulatory element tightly linked to theGpdh locus inDrosophila melanogaster has been isolated from a natural population. Flies homozygous for second chromosomes bearing the element,H31, have half the GPDH activity of normal homozygotes. Heterozygotes betweenH31 andF orS alleles exhibit dominance in GPDH activity. Heterozygotes betweenH31, F orS andDf(2L) GdhA have half the diploid level. The contribution of theS allele to the activity inS/H31 heterozygotes is more than four times that ofH31. The regulatory element distinguishingH31 is tightly linked to theGpdh + locus.
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  • 7
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    Cellular and molecular life sciences 42 (1986), S. 600-604 
    ISSN: 1420-9071
    Keywords: Drosophila ; temperature-effects ; pupation ; mating ; oviposition ; adaptive strategies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A comparison of pupation-temperature range was made in the laboratory on a temperature gradient (3–38°C) using 12 species ofDrosophila representing four species groups and four different ecological backgrounds (temperate-montane forest:virilis group; desert;repleta group; cosmopolitan:melanogaster group; tropical forest:willistoni group). Within groups, differences are found which usually reflect species' distributions. Comparisons of species' mating-, oviposition- and pupation-temperature ranges reveal that pupation most-often occurs at temperatures beyond those for mating and oviposition. Each species reflects a different combination of temperature effects. Individual species have different temperature-limits for mating, oviposition and pupation. Temperatures permissive for one response are not predictive of limits on other responses. Among species, temperature can affect a particular response differently. Within groups, species differences can be at high and/or low temperatures for any response, and temperature effects among closely related species can manifest themselves in one, or any combination of responses. One cannot predict which responses will be most and least limited, or at which end of the temperature scale a response will be most limited. Among groups,common, but notabsolute temperature ranges generally correspond to the geographic distributions and ecological backgrounds of the species triads. The evaluation of temperature effects on species, based on a single activity, may not be adequate for predicting adaptive strategies.
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  • 8
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    Development genes and evolution 195 (1986), S. 22-32 
    ISSN: 1432-041X
    Keywords: Drosophila ; Cell lineage ; Malpighian tubules ; Compartments ; Cell death
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Genetically marked maroon-like (mal) clones were induced by mitotic recombination with X-rays at the blastoderm stage in mal/mal + heterozygotes and were analysed in differentiated Malpighian tubules (MT). Marked cells were not confined to single anterior (MA) or posterior (MP) tubules, but were distributed among the four tubules. About 70% of the clones with two or more cells were fragmented, i.e. mal cells were separated by wild-type cells. Since the clones contain, on average, 6 cells and the differentiated MT consist of 484 cells (2 × 136 MA cells, 2 × 106 MP cells), we estimate that there are about 80 cells in the blastoderm anlage which on average pass through two to three mitoses. With increasing radiation doses (254 R, 635 R, 1270 R) a linear increase in clone frequency is observed. The mean sizes and size distributions of clones, however, remain unchanged. Since the increasing radiation dose also results in fewer differentiated Malpighi cells, we assume that regeneration does not occur. Therefore, size distributions of marked clones presumably represent real mitotic patterns in normogenesis. We suggest that essentially three successive mitoses take place, with a decreasing fraction of cells showing mitotic activity. Only a small fraction of cells goes through a fourth or even a fifth mitosis. Marked non-Minute clones induced in Minute heterozygotes are more frequent, but are not larger than non-Minute clones in wild-type background. Therefore, compartment boundaries cannot be recognized by this method. However, frequencies of marked cells found simultaneously in MA and MP pairs or in several single tubules of the same individuals are significantly higher than frequencies of multiple recombination events predicted by the Poisson distribution. From this, we conclude that neither the MA pair nor the MP pair nor single tubules represent compartments of the MT anlage.
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  • 9
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    Development genes and evolution 195 (1986), S. 389-398 
    ISSN: 1432-041X
    Keywords: Cell lineage ; Embryogenesis ; Drosophila ; Cell marking ; Cell transplantation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A method is presented which allows the study of the progeny of single cells during Drosophila embryogenesis. Cells from various larval anlagen of donor embryos labelled with a lineage tracer are individually transplanted from defined positions into similar, or different, positions in unlabelled hosts. The clones produced by these cells can be seen in whole mounts or in sections of fixed material, when using a histochemical marker (i.e. HRP), and/or in living embryos, when using fluorescent lineage tracers. The characteristics of the clones disclose lineage parameters, such as division patterns, morphogenetic movements and differentiation. The method is especially useful for testing the respective roles of positional information and cell lineage on the commitment of progenitor cells by transplanting these cells into heterotopic positions or into hosts of different genotypes.
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  • 10
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    Development genes and evolution 195 (1986), S. 334-337 
    ISSN: 1432-041X
    Keywords: Suppression ; P elements ; Lethality ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In this paper we describe a new allele of suppressor of forked, su(f) hd37, referred to as hd37, which was isolated in a hybrid dysgenesis mutation screen and is shown to be P induced by its high frequency of reversion in hybrid dysgenic crosses, and by in situ hybridization. hd37 suppresses forked and fails to complement the forked suppression of known su(f) alleles. However, it complements the recessive lethality of alleles in both of the su(f) lethal complementation groups. We also describe a new phenotypic effect of su(f) alleles, the enhancement of Minute(3)i 55. Recessive lethal alleles enhance the lethal effects of this Minute, but hd37 does not. The temperature sensitive period for forked bristle suppression by hd37 was found to be very narrow, consisting of a short interval (12–18 h) immediately before bristle formation. These results suggest that the several genetic functions associated with this locus may be genetically separable.
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  • 11
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    Development genes and evolution 188 (1980), S. 163-177 
    ISSN: 1432-041X
    Keywords: Yolk sac ; Ultrastructure ; Embryogenesis ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Changes at the ultrastructural level during germ band extension in the embryo ofDrosophila melanogaster are described. Cytoplasmic connections between cells and the yolk sac are present during initial cellular movements. At this time, a continuous system of microfilaments is present adjacent to the membranes in the connections and at the periphery of the yolk sac. As germ band extension progresses, this system becomes discontinuous, and microfilaments are apparent only in the immediate vicinity of the connections. Cytoplasmic connections are disassembled at approximately the midpoint of extension; at the same time, extensive membrane associations develop between germ band cells and between these cells and adjacent yolk sac membranes. Positioning and orientation of cytoplasmic connections suggest that the yolk sac, via these connections, is actively involved in the cellular movements of early germ band extension.
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  • 12
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    Development genes and evolution 189 (1980), S. 57-67 
    ISSN: 1432-041X
    Keywords: Drosophila ; Ecdysone deficient mutants ; Ecdysteroid titer ; Ring gland ; Fine structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This paper describes two ecdysone-deficient, recessive-lethal mutants,lethal(1)giant ring gland (grg) andlethal(1)suppressor of forked mad-ts (mad-ts: Jürgens and Gateff 1979) and compares their ecdysteroid titers with that of the wild-type. Mutant larvae show a much reduced ecdysteroid content, amounting to 1/10 to 1/30 of the wild-type values, but never a true titer peak. They fail to pupate and die after 1–3 weeks. Ecdysteroid feeding elicits different responses in the larvae of the two mutants.mad-ts larvae pupate within 24 h, thus showing that their low ecdysteroid titer is directly connected to their inability to pupate.mad-ts resembles the mutantlethal (3)ecdysone-1 ts (Garen et al. 1977). Thegrg mutant larvae, on the other hand, fail to pupate after 20-hydroxyecdysone feeding as well as injection. The primary defect of thegrg mutant is not entirely clear. Thegrg larval salivary gland cells appear to possess normal ecdysteroid receptors. Furthermore, the low ecdysteroid titer ingrg is not the result of an increased ecdysteroid catabolism. The primary defect in the mutant may lie in the malfunctioning neurosecretory cells which do not show neurosecretion in histological preparations. Further support for this notion comes from electronmicrographs of the enlargedgrg ring glands which, in contrast to the wild-type, do not possess nerve endings. In the wild-type three ecdysteroid peaks were found: one shortly before puparium formation, the second at approximately 12 h and the third at about 30 h after pupation. The ecdysteroid titer peak in late third instar, wild-type larvae is mainly due to the presence of 20-dydroxyecdysone as shown by radioimmunoassays after thin layer chromatography and derivatization followed by gas liquid chromatography and mass spectroscopy. In addition, a number of unidentified polar and apolar metabolites were also present.
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  • 13
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    Development genes and evolution 188 (1980), S. 157-161 
    ISSN: 1432-041X
    Keywords: Drosophila ; Imaginal discs ; Compartments ; Distal outgrowth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Peripheral tissue of the imaginal wing disc gives rise to the proximal mesothoracic structures of the adult. Pieces of peripheral tissue, which have no regenerative capacity when cultured as intact fragments, are capable of distal outgrowth (regeneration) after dissociation and reaggregation. This ability depends on the region of the disc periphery from which the fragment is taken. Extensive distal outgrowth occurs in reaggreages of a fragment containing equal proportions of tissue from anterior and posterior developmental compartments. The extent of outgrowth decreases as the proportion of posterior tissue is reduced, so that a fragment containing only anterior tissue shows no regeneration after dissociation. Limited distal outgrowth occurs in reaggregates of a wholly posterior fragment, but the regenerative capacity is increased greatly when a small amount of anterior tissue is included. It is concluded that distal outgrowth in the wing disc requires an interaction between cells of the anterior and posterior compartments.
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  • 14
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    Development genes and evolution 189 (1980), S. 91-96 
    ISSN: 1432-041X
    Keywords: Epimorphic regulation ; Drosophila ; Imaginal discs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary It has been known for many years that when a wing disc ofDrosophila is bisected, and the fragments cultured in adult females, regulation occurs and either a complete disc is regenerated or the fragment is duplicated. We have investigated how this regeneration process occurs. To establish which cells contribute to the regenerate, and thus determine if regeneration is the result of epimorphic regulation, fragments of discs, after culture in an adult for one to five days, were exposed to3H-thymidine to label replicating cells. Imaginal discs, both whole and as regenerating fragments, undergo some DNA replication which is distributed throughout the disc, but cut discs frequently show clusters of labelled cells around the wound, indicating that regeneration is probably epimorphic.
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  • 15
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    Development genes and evolution 195 (1986), S. 210-221 
    ISSN: 1432-041X
    Keywords: Peripheral nervous system ; Neurogenesis ; Mutants ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mutations previously known to affect early neurogenesis inDrosophila melanogaster have been found also to affect the development of the peripheral nervous system. Anti-HRP antibody staining has shown that larval epidermal sensilla of homozygous mutant embryos occur in increased numbers, which depend on the allele considered. This increase is apparently due to the development into sensory organs of cells which in the wild-type would have developed as non-sensory epidermis. Thus, neurogenic genes act whenever developing cells have to decide between neurogenic and epidermogenic fates, both in central and peripheral nervous systems. Different regions of the ectodermal germ layer are distinguished with respect to their neurogenic abilities.
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  • 16
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    Development genes and evolution 195 (1986), S. 302-317 
    ISSN: 1432-041X
    Keywords: Drosophila ; Maternal effect Mutations ; Pattern formation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mutations in seven different maternal-effect loci on the second chromosome of Drosophila melanogaster all cause alterations in the anterior-posterior pattern of the embryo. Mutations in torso (tor) and trunk (trk) delete the anterior- and posterior-most structures of the embryo. At the same time they shift cellular fates which are normally found in the subterminal regions of the embryo towards the poles. Mutations in vasa (vas), valois (vls), staufen (stau) and tudor (tud) cause two embryonic defects. For one they result in absence of polar plasm, polar granules and pole cells in all eggs produced by mutant females. Secondly, embryos developing inside such eggs show deletions of abdominal segments. In addition, embryos derived from staufen mothers lack anterior head structures, embryos derived from valois mothers frequently fail to cellularize properly. Mutations in exuperantia (exu) cause deletions of anterior head structures, similar to torso, trunk and staufen. However in exu, these head structures are replaced by an inverted posterior end which comprises posterior midgut, proctodeal region, and often malpighian tubules. The effects of all mutations can be traced back to the beginning stages of gastrulation, indicating that the alterations in cellular fates have probably taken place by that time. Analysis of embryos derived from double mutant mothers suggests that these three phenotypic groups of mutants interfere with three different, independent pathways. All three pathways seem to act additively on the system which specifies anterior-posterior cellular fates within the egg.
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  • 17
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    Development genes and evolution 195 (1986), S. 145-157 
    ISSN: 1432-041X
    Keywords: Drosophila ; Cell polarity ; Limb development ; Pattern formation ; Bristle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The legs of flies from 16 different mutant strains ofDrosophila melanogaster were examined for abnormal cuticular polarities and extra joints. The strains were chosen for study because they manifest abnormal cuticular polarities in some parts of the body (10 strains) or because they have missing or defective tarsal joints (6 strains). All but three of the stocks were found to exhibit misorientations of either the bristles, hairs, or “bract-socket vectors” on the legs. The latter term denotes an imaginary vector pointing from a hairlike structure called a “bract” to the bristle socket with which it is associated. On the legs of wild-type flies nearly all such vectors point distally, as do the bristles and hairs. In the mutant flies, the most common vector misorientation is a 180° reversal. When the bract-socket vectors of adjacent bristle sites in the same bristle row point toward one another, the distance between the sites is frequently abnormally large, whereas when the vectors point in opposite directions, the interval is frequently abnormally small. This correlation is interpreted to mean that bristle cells actively repel one another via cytoplasmic extensions that are longer in the direction of the bract-socket vector than in the opposite direction. Repulsive forces of this kind may be responsible for “fine-tuning” the regularity of bristle spacing in wild-type flies. Extra tarsal joints were found in eight of the 16 strains. A ninth strain completely lacking tarsal joints appears in some cases to have an extra tibia-basitarsus joint in its tibia. Whereas the tarsi of wild-type flies contain four joints, the tarsi ofspiny legs mutant flies contain as many as eight joints. In this extreme extra-joint phenotype, four of the joints correspond to the normal wild-type joints, and there is an extra joint in every tarsal segment except the distal-most (fifth) segment. Nearly all such ectopic extra joints have inverted polarity. In other strains the extra tarsal joints are located mainly at the wild-type joint sites, and joints of this sort have wild-type polarity. The alternation of normal and inverted (extra) joints inspiny legs resembles the alternation of normal and inverted (extra) body segment boundaries in the embryonic-lethal mutantpatch, suggesting that tarsal and body segmentation may share a common patterning mechanism.
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  • 18
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    Development genes and evolution 195 (1986), S. 222-228 
    ISSN: 1432-041X
    Keywords: Sense organs ; Drosophila ; Pattern formation ; Peripheral nervous system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Various types of sense organs are arranged in a highly reproducible pattern on the thoracic and abdominal segments ofDrosophila embryos and larvae. We describe this pattern and identify the neurons that innervate each sense organ. This identification is confirmed by the analysis of partial deficiencies for the scute region, which delete specifically some of the sense organs and their innervating neurons. Since our description of the sense organs accounts for all the sensory neurons that have been identified in the embryo, we believe that this description is accurate and complete, except in the terminal segment, where some sense organs remain to be identified.
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  • 19
    ISSN: 1432-041X
    Keywords: Determination ; Germ-line ; Somatic cells ; Inhibitor gradient hypothesis ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A hypothesis is presented which explains the segregation of germ cells from somatic cells, and the subsequent determination of both cell types with a single mechanism. This hypothesis is in part based on that of Meinhardt (1977) and can be summarized as follows: In the newly fertilized egg, the action of a sink in the pole plasm leads to the formation of an anterior-posterior gradient of an inhibitor. The concentration of this inhibitor in the posterior 20% of the egg is below that needed to repress synthesis of an activator. When, during the nuclear division stage, nuclei enter this posterior region, synthesis of the activator begins. As the activator is autocatalytic, this leads to the formation of a peak of activator in this region; and since the activator also catalyses the synthesis of the inhibitor, a peak of inhibitor is formed in the same place. The inhibitor then diffuses anteriorly through the periplasm, forming a posterior-anterior gradient. The presence of this inhibitor in the periplasm causes the nuclei that enter the periplasm to form blastoderm cells and to take up particular segmental states appropriate to their position, while those that remain in the yolk-containing plasm develop into vitellophages. The action of the sink in the pole plasm is postulated to result in the formation of the pole cells, and subsequently to direct some of these into forming cells of the germ-line.
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  • 20
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    Development genes and evolution 189 (1980), S. 1-15 
    ISSN: 1432-041X
    Keywords: Cell line ; Drosophila ; Ecdysone ; Ecdysterone ; Hormones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cells of the line Kc, derived fromDrosophila melanogaster embryos, extend long processes when exposed to ecdysteroid hormones. We have devised a quantitative assay for this morphological response, using the subline Kc-H. The assay was used to characterize the conditions required for the response. A halfmaximal response is elicited by approximately 10−8M 20-hydroxyecdysone; the response is saturated by 10−7M 20-hydroxyecdysone, which causes detectable elongation within a few hours, and a maximal response after 2–3 days. The response occurs substantially normally in the absence of serum, during growth in suspension, and in over-crowded cultures. It is not elicited by cyclic nucleotides, vertebrate growth factors, or a variety of other non-ecdysteroid reagents. Of 60 ecdysteroid compounds tested, only those which were active in other insect test systems elicited the response, and the concentrations required were approximately proportional to the concentrations active in other in vitro systems. We conclude that the response of Kc cells to 20-hydroxyecdysone retains basic features of the ecdysteroid response of intact tissues and therefore that Kc cells are a useful model system for studying ecdysteroid action.
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  • 21
    ISSN: 1432-041X
    Keywords: Eggshell ; Chorion ; Peroxidase ; Crosslinking ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary TheDrosophila chorion contains an endogenous peroxidase activity which remains inactive until late stage 14 when it catalyzes the crosslinking of the chorionic proteins. Using explanted follicles developing in vitro, premature, but otherwise normal crosslinking can be induced with hydrogen peroxide and normal crosslinking can be prevented with peroxidase inhibitors. Inhibition or premature activation of the shell peroxidase allows characterization of chorionic filament specific proteins and establishes new criteria for the identification of eggshell components.
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  • 22
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    Development genes and evolution 188 (1980), S. 153-156 
    ISSN: 1432-041X
    Keywords: Drosophila ; Embryogenesis ; mat (3) 1 mutation ; Two-dimensional gels
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The synthesis of a protein which has been detected in blastoderm cells but not in pole cells (Gutzeit and Gehring 1979) has been studied further by means of two-dimensional gel electrophoresis. This protein could not be detected at the nuclear multiplication stage. The protein is translated from mRNA which is transcribed at the blastoderm stage since it is not synthesized in detectable amounts when embryos are injected with α-amanitin prior to the blastoderm stage. Also the protein could not be detected when RNA from freshly laid eggs was translated in vitro. Embryos from females which are homozygous for the mutationmat (3) 1 form pole cells but no blastoderm cells (Rice and Garen 1975). Thesemat (3) 1 embryos, as we will call them in this report, express the protein if aged for a period of time sufficient for completion of blastoderm cell formation in control wild-type embryos.mat (3) 1 embryos and embryos injected with α-amanitin show the same syndrome of visible developmental anomalies; however, the studied protein could only be detected inmat (3) 1 embryos but not in α-amanitin injected embryos.
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  • 23
    ISSN: 1432-041X
    Keywords: Drosophila ; Geographic strains ; Chorion proteins ; Electrophoretic variants ; Chorion gene linkage
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    Topics: Biology
    Notes: Summary Drosophila melanogaster chorion proteins are characterized on one-dimensional isoelectric focusing (IF) gels. The six major chorion components previously identified on SDS gels are shown to resolve into at least 11 components in our IF system. IF screening of 102 geographic strains ofDrosophila melanogaster revealed seven cases of variation in major chorion components. Two strains, Crimea and Falsterbo, which were monomorphic for a variant B1 protein and two strains, Skafto and Lausanne, which were monomorphic for a variant C1 protein, were chosen for further study. After IF developmental analysis of F1 hybrids had indicated that the sources of the variation resided in the structural genes for these proteins, each variant was crossed to a multiply marked and inverted strain (BLT) to determine the linkage group of the variant gene. To localize genes to more specific sites multiply marked 3rd (SKERO) or X-chromosomal (CB1) (X-PLE) mapping strains were used. In both Crimea and Falsterbo the gene for the B1 protein is located near map location 26 on the 3rd chromosome. In both Lausanne and Skafto the C1 gene is located on the X chromosome. Hence, for the first time, we have demonstrated genetically the non-linkage of two chorion genes, B1 and C1.
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    Development genes and evolution 189 (1980), S. 147-153 
    ISSN: 1432-041X
    Keywords: Homeotic mutant ; Drosophila ; Clonal analysis ; Timing of gene action ; Determination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Nasobemia (Ns) is a dominant homeotic mutant ofDrosophila melanogaster which converts parts or all of the antenna to mesothoracic leg.Ns has a temperature sensitive period between 48 and 60 h. The hypothesis thatNs acts during this period and is not required thereafter to maintain the homeotic transformation to leg was tested by removingNs fromNs/+ cells at different stages of development through X-ray induced somatic recombination. The expression of theNs homeotic transformation in recombinant wild type (+/+) cells increased sharply between 48 and 65 h. In clones induced after 65 h the expression of the leg transformation was equal in large and small +/+ clones. We interpret these results as supporting the hypothesis that transient action ofNs between 48 and 65 h switches antennal cells to a clonally stable leg determined state whose maintenance does not require futherNs action.
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    Development genes and evolution 195 (1986), S. 445-454 
    ISSN: 1432-041X
    Keywords: Neural and epidermal cell lineages ; Embryogenesis ; Drosophila
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    Topics: Biology
    Notes: Summary Some aspects of neural and epidermal cell lineages during embryogenesis of Drosophila melanogaster were studied by transplanting horseradish-peroxidase-(HRP-) labelled ectodermal cells from young gastrula donors into host embryos of similar ages. Heterotopic transplantations permitted us to assess the degree of commitment already attained by the transplanted cells. The resulting cell clones showed normal characteristics of cytodifferentiation and cell number. The results indicate that epidermal progenitors perform a maximum of three mitoses during embryonic development, whereas neuroblasts may perform more than ten mitoses. Clone size distribution is in both cases scattered, suggesting either a rather irregular mitotic pattern or cell death. As indicated by heterotopic transplantations, the neurogenic ectoderm for the ventral nervous system exhibits different neurogenic abilities in its different regions, decreasing from medial to lateral; we discuss the hypothesis that some medially located cells of the young gastrulating embryo could be committed towards the neural fate before segregating from the ectoderm. On the other hand, the cells of the dorsal ectodermal regions at the same stage seem to be indifferent with respect to commitment, for they are able to give rise to central neural lineages following their transplantation in the neurogenic region.
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  • 26
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    Cellular and molecular life sciences 42 (1986), S. 846-848 
    ISSN: 1420-9071
    Keywords: Drosophila ; bristles ; phenotype ; directional selection ; chaetogen
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    Topics: Biology , Medicine
    Notes: Summary The variations of the dorsocentral and scutellar bristle patterns founded in two bidirectionaly selected lines are discussed in terms of the Richelle and Ghysen model. The phenotype obtained through selection for bristle suppression can be accounted for by a decrease in chaetogen production. Extra bristles can be accounted for by an alteration of the response of the cells to positional information.
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  • 27
    ISSN: 1432-1939
    Keywords: Yeast ; Drosophila ; Host plants ; Communities ; Vectors
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    Topics: Biology
    Notes: Summary The yeast communities from slime fluxes of three deciduous trees (Prosopis juliflora, Populus fremontii and Quercus emoryi) and the necroses of two cacti (Opuntia phaeacantha and Carnegiea gigantea) were surveyed in the region of Tucson, Arizona. In addition, the yeasts carried by dipterans associated with the fluxes or necroses (Drosophila carbonaria, D. brooksae, D. nigrospiracula, D. mettleri, and Aulacigaster leucopeza) were sampled. The results indicate that each host sampled had a distinct community of yeasts associated with it. The dipterans, which can act as vectors of the yeasts, deposited yeasts from other sources in addition to those found on their associated hosts. It is argued that host plant physiology is relatively more important than the activity of the vector in determining yeast community composition. Furthermore, the average number of yeast species per flux or necrosis is not different from the average number of yeast species per fly. It is hypothesized that the vector may affect the number of species per individual flux or not, and that the number is lower than the rot or necrosis could potentially support.
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    Biochemical genetics 24 (1986), S. 683-699 
    ISSN: 1573-4927
    Keywords: Drosophila ; aldox-2 ; molybdoenzymes
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The aldox-2 locus in Drosophila melanogaster has been shown to affect differentially three molybdoenzymes, aldehyde oxidase, pyridoxal oxidase, and xanthine dehydrogenase. These effects are most obvious at times surrounding the pupal-adult boundary, when the normal organism accumulates large amounts of these enzymes in their active form. This locus has been more precisely mapped genetically to 2–82.9±2.1, with complete concordance between the effects of all recombinant chromosomes on all three enzymes. The cytogenetic location has also been determined to be between 52E and 54E8, with the likelihood that it lies within the region 54B1-54E8. The aldox-2 mutant allele has no visible phenotype and is completely recessive for enzyme effects at all stages tested. Segmental duplication of this region, including the aldox-2 + allele, has no apparent effect on the visible phenotype or the enzymatic activity. The mutant aldox-2 allele has no effect on the developmental expression of two unrelated enzymes, 6-phosphogluconate dehydrogenase and NADP+-dependent isocitrate dehydrogenase. The effects of this locus on aldehyde oxidase, xanthine dehydrogenase, and pyridoxal oxidase suggest that this locus may code for a product involved in the synthesis of the molybdenum cofactor common to these enzymes.
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    Biochemical genetics 24 (1986), S. 291-308 
    ISSN: 1573-4927
    Keywords: Drosophila ; aldehyde oxidase ; gene dosage ; Aldox
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Aldox “null” alleles which were isolated from natural populations in Great Britain and North Carolina were analyzed for complementation. No complementation was observed between any combinations of “null” alleles for aldehyde oxidase (AO) specific activity in late third-instar larvae and newly emerged adults. AO immunologically cross-reacting material (AO-CRM) was quantitated in all homozygous stocks at both developmental stages as well as all allelic combinations in newly emerged adults. When the adult organism contains only Aldox n alleles, the polypeptides are not immunologically recognizable or may be rapidly degraded. Larvae and adults have different abilities to degrade mutationally altered enzymatically inactive AO polypeptide or synthesize them differentially. This is indicated by easily measurable AO-CRM levels in late third-instar larvae of Aldox n homozygotes, while newly emerged adult Aldox n homozygotes have very little, if any, AO-CRM. Newly emerged adult heterozygotes of Aldox n /Aldox + do have increased AO-CRM, indicating that the Aldox n alleles can code for a polypeptide which can be “rescued” if Aldox + gene product is present. Heterozygotes containing an Aldox + allele with a deficiency for the Aldox region produce 74.2% of the AO-CRM found in Aldox + homozygotes. This may indicate the presence of trans-acting factors which serve to activate gene expression in a system in which each gene copy is not maximally expressed.
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  • 30
    ISSN: 1573-4927
    Keywords: Drosophila ; ontogeny ; amylase ; α-glucosidases ; functional significance
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Changes in amylase (E.C. 3.2.1.1), maltase (E.C. 3.2.1.20), sucrase, and PNPGase activities in relation to changes in wet weight and protein content were studied during the development of larvae and adult flies from two strains of Drosophila melanogaster, homozygous for different amylase alleles. All α-glucosidase activities increase exponentially during a large part of larval development, parallel to the increase in weight, and drop at the end of the third instar. Amylase activity of the Amy 1 strain follows the same pattern. In contrast, amylase activity of the Amy 4,6 strain continues its exponential increase longer. In the third larval instar amylase activity in the Amy 4,6 strain becomes much higher than in the Amy 1 strain. During the first hours of adult life amylase activity of the two strains does not differ. Then Amy 4,6 activity starts to rise and becomes much higher (4–5 times) than Amy 1 amylase activity, which remains approximately constant. All adult enzyme activities are much higher than in larvae. Comparison of enzyme activity of amylase and α-glucosidases in larvae and adults confirms that differences in amylase activities can become important only when starch is a limiting factor in the food.
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    Biochemical genetics 18 (1980), S. 439-454 
    ISSN: 1573-4927
    Keywords: Drosophila ; acetylcholinesterase ; insecticide resistance ; electrophoretic variation
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We examined the Canton-S strain of Drosophila melanogaster for electrophoretic variation of the enzyme acetylcholinesterase. The pattern of bands obtained (stained with acetylthiocholine) depended on age, sex, and tissue (i.e., head vs. body part and hemolymph). However, through mixing experiments, it was concluded that most of these apparent differences were due to modification of the enzyme by unknown substances located in the fly's body. The electrophoretic pattern of head acetylcholinesterase was altered so that it became characteristic of the body which was present during extraction. For example, when heads of D. melanogaster were homogenized in an extract from D. lebanonensis bodies, the characteristic AChse bands of melanogaster were absent and instead the bands of lebanonensis were found. it was found that extraction of adult heads in 0.1 M potassium phosphate buffer alone or with a 2-min exposure to 1 mg/ml trypsin at 20 C gave the most reproducible results, independent of age and sex. Using these conditions, 25 strains of D. melanogaster and 30 strains of D. pseudoobscura were examined without finding any reproducible electrophoretic variant of acetylcholinesterase. In addition, 53 strains from 39 other Drosophila species produced a total of only six electrophoretic forms of the head enzyme. Additional electromorphs were found when whole flies were used, but these were not studied in detail because of the possibility that they could be due to postextraction modification.
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    Biochemical genetics 18 (1980), S. 717-726 
    ISSN: 1573-4927
    Keywords: Drosophila ; 5-fluorouracil ; drug response ; thymidylate synthetase
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Mutant strains sensitive and resistant to the drug 5-fluorouracil (FU) have been isolated from the wild-type Pac strain of Drosophila melanogaster. The resistant strain, termed flur, is resistant to at least 0.0035%FU (2.7 × 10−4 m) in the food media and exhibits cross-resistance to 5-fluorodeoxyuridine (FUdR) but not to 5-fluorouridine (FUR). The sensitive strain termed flu S , exhibits over 90% mortality on 0.0008% FU (6 × 10−5 m). Genetic analysis indicates that the flu gene is located on the third chromosome, which agrees with results of previous workers. An analysis of the enzyme thymidylate synthetase from the selected sensitive and resistant strains indicates that the resistant strain enzyme possesses an elevated specific activity. Levels 4 times that of the sensitive strain were observed when the enzymes were assayed at 20 C. This increase is apparently not due to induction by FU in the food media. It is suggested that the enzyme thymidylate synthetase may be involved in the resistance process.
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    Biochemical genetics 18 (1980), S. 781-791 
    ISSN: 1573-4927
    Keywords: Drosophila ; phenylalanine hydroxylase ; developmental regulation
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Herein we demonstrate that Drosophila larvae possess a synthetic activity capable of converting phenylalanine to tyrosine. This system is readily extractable and displays many characteristics of phenylalanine hydroxylase systems described in other organisms, the most notable being that a tetrahydropteridine is required for full expression of activity. The level of phenylalanine hydroxylase activity present in the organism varies with the stage of development: from an undetected level of activity at the first larval instar, there is a rapid increase in phenylalanine hydroxylase activity which reaches a peak at the time of puparium formation, after which there is a rapid decrease again to an undetected level.
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    Biochemical genetics 18 (1980), S. 929-937 
    ISSN: 1573-4927
    Keywords: glucose oxidase ; glucose metabolism ; Drosophila ; sex specific
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A glucose oxidase (GO) has been identified in the ejaculatory duct of male Drosophila melanogaster. Evidence is given that this enzyme was previously misidentified as HEX-1. Genetic analysis indicates that the Go structural gene is located on the third chromosome at 48 ± 0.5 cm. Go is polymorphic in males in populations of D. melanogaster and D. simulans located in Athens, Georgia. Two other hexose enzymes have also been tentatively identified for the first time in Drosophila. These are NAD(P)-glucose dehydrogenase (GODH) and NAD-gluconate dehydrogenase (GNDH). GODH and GNDH are found in both males and females and may circumvent the initial steps in the pentose shunt.
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    Biochemical genetics 24 (1986), S. 873-889 
    ISSN: 1573-4927
    Keywords: Drosophila ; alcohol dehydrogenase ; temperature ; adaptation ; enzyme polymorphism
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The gene products of the two major alleles of alcohol dehydrogenase (ADH-F and ADH-S) have been subjected to kinetic and biochemical analyses over a range of temperatures. Although temperature was found to have a significant effect on both kinetic and biochemical properties ofDrosophila ADH, no significant differential effect was observed between the major ADH allozymes. The results are discussed within the context of the selective maintenance ofAdh polymorphism in natural populations.
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  • 36
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    Biochemical genetics 24 (1986), S. 859-872 
    ISSN: 1573-4927
    Keywords: Drosophila ; alcohol tolerance ; glycerol-3-phosphate oxidase
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The role of sn-glycerol-3-phosphate oxidase (GPO; EC 1.1.99.5) in the variation of ethanol tolerance inDrosophila melanogaster was assessed in isofemale lines derived from individuals collected at the Chateau Tahbilk Winery and Wandin North Orchard of Victoria, Australia. When fed an undefined medium (semolina-treacle) with 6% ethanol (v/v), larvae of lines with high GPO activities survived better than did larvae of lines with low GPO activities. Although GPO was induced to higher activity levels by dietary ethanol in larvae of all the test lines, GPO activity was greater in lines representing the area outside the wine cellar. This implied that the cellar environment selected against individuals with high levels of GPO. These data do not explain the established difference in tolerance between cellar and outside populations. The GPO activities of lines were not dependent upon the activities of the lipogenic enzyme, glycerol-3-phosphate dehydrogenase; the major ethanol-degrading enzyme, alcohol dehydrogenase; or the citric acid cycle enzyme, fumarase. Thus, GPO activity is an important component of the metabolic mechanism of ethanol tolerance in larvae, but the mode of action of GPO has not been defined.
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    Journal of chemical ecology 12 (1986), S. 1037-1055 
    ISSN: 1573-1561
    Keywords: Drosophila ; Diptera ; Drosophilidae ; yeasts ; cactus ; community ecology ; mutualism ; coadaptation ; evolution ; alkaloids ; fatty acids ; sterols
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The mutualistic interactions of cactophilicDrosophila and their associated yeasts in the Sonoran Desert are studied as a system which has evolved within the framework of their host cactus stem chemistry. Because theDrosophila-yeast system is saphrophytic, their responses are not thought to directly influence the evolution of the host. Host cactus stem chemistry appears to play an important role in determining where cactophilicDrosophila breed and feed. Several chemicals have been identified as being important. These include sterols and alkaloids of senita as well as fatty acids and sterol diols of agria and organpipe cactus. Cactus chemistry appears to have a limited role in directly determining the distribution of cactus-specific yeasts. Those effects which are known are due to unusual lipids of organpipe cactus and triterpene glycosides of agria and organpipe cactus.Drosophilayeast interactions are viewed as mutualistic and can take the form of (1) benefits to theDrosophila by either direct nutritional gains or by detoxification of harmful chemicals produced during decay of the host stem tissue and (2) benefits to the yeast in the form of increased likelihood of transmission to new habitats. Experiments on yeast-yeast interactions in decaying agria cactus provide evidence that the yeast community is coadapted. This coadaptation among yeasts occurs in two manners: (1) mutualistic increases in growth rates (which are independent of the presence ofDrosophila larvae) and (2) stabilizing competitive interactions when growth reaches carrying capacity. This latter form is dependent on larval activity and results in benefits to the larvae present. In this sense, the coadapted yeast community is probably also coadapted with respect to itsDrosophila vector.
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    Behavior genetics 10 (1980), S. 401-407 
    ISSN: 1573-3297
    Keywords: sexual isolation ; Drosophila ; geographic distance ; isolation index ; resource utilization
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    Topics: Biology , Psychology
    Notes: Abstract Six strains of the cosmopolitan speciesD. immigrans from the Australian life zone plus one from the USA, show weak sexual isolation and more rarely sexual selection. Levels of sexual isolation cannot be related to geographic distances. Assortative mating may have evolved as a byproduct of ecological divergence.
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  • 39
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    Behavior genetics 16 (1986), S. 271-279 
    ISSN: 1573-3297
    Keywords: Drosophila ; habitat choice ; learning ; experience
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    Topics: Biology , Psychology
    Notes: Abstract Microhabitat preferences ofDrosophila pseudoobscura strains were examined in a Waddington maze, with an emphasis on learning how early environment affected adult habitat choice. The genotypes were roughly those expected in a natural population; the environmental variables included light, temperature, and food. It was found that (1) the different genotypes chose habitats differently; (2) early experience affected subsequent habitat choice; and (3) the effect of early experience was complex, as preference for one niche dimension (temperature) was reinforced by experience with the generally preferred value, preference for another niche dimension (light) was weakened by experience with the generally preferred value, and preference for other niche dimensions (food) was generally unaffected by experience. In this study the contribution to the total chi square was about equal from genotype and from environment. The significance of these findings for studies of dispersal and population structure of natural populations is discussed.
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  • 40
    ISSN: 1573-3297
    Keywords: Drosophila ; learning ; memory ; classical conditioning ; mutants
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    Topics: Biology , Psychology
    Notes: Abstract Holliday & Hirsch (this issue) now agree that “Quinnet al. (1974) have demonstrated learning [inDrosophila] with group data, and their inability to identify individual differences (IDs) in performance does not invalidate their conclusion that some individuals in the population must have learned.” However, they consider it important, if not necessary, to show that anindividual fly has learned. In response to Holliday and Hirsch, this paper discusses why it is not necessary to measure learning in individual fruit flies before searching for underlying biochemical mechanisms.
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  • 41
    ISSN: 1573-4927
    Keywords: ethanol ; lipid ; alcohol dehydrogenase ; Drosophila ; nutrition
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract At a moderate concentration (2.5%, v/v) dietary ethanol reduced the chain length of total fatty acids (FA) and increased the desaturation of short-chain FA in Drosophila melanogaster larvae with a functional alcohol dehydrogenase (ADH). The changes in length in total FA were postulated to be due to the modulation of the termination specificity of fatty acid synthetase. Because the ethanol-stimulated reduction in the length of unsaturated FA was blocked by linoleic acid, it was thought to reflect the properties of FA 9-desaturase. Although the ethanol-stimulated reduction in chain length of unsaturated FA was also observed in ADH-null larvae, ethanol promoted an increase in the length of total FA of the mutant larvae. Thus, the ethanolstimulated change in FA length was ADH dependent but the ethanol effect on FA desaturation was not. Ethanol also stimulated a decrease in the relative amount of phosphatidylcholine and an increase in phosphatidylethanolamine. Because similar ethanol-induced changes have been found in membrane lipids of other animals, ethanol may alter the properties of membranes in larvae. It is proposed that ethanol tolerance in D. melanogaster may be dependent on genes that specify lipids that are resistant to the detrimental effects of ethanol.
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  • 42
    ISSN: 1573-4927
    Keywords: flight metabolism ; Drosophila ; αGPDH ; Kacser-Burns
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Measurements of wing-beat frequency (WBF) have been used to characterize flight muscle metabolic rate in Drosophila melanogaster during tethered flight. Progeny of crosses between 17 X-chromosome substitution lines and three null-activity stocks have been studied in order to determine the effect on flight metabolism of sharply reduced activity of α-glycerophosphate dehydrogenase (αGPDH). It was found that flies with an approximate 50% reduction in αGPDH activity have a metabolic rate that is, in most cases, indistinguishable from that of wild-type flies and, in the most extreme cases, reduced by only 4%. These results demonstrate that αGpdh is not a “major gene” for flight metabolism, in the quantitative genetic sense of the term. These results are in agreement with the Kacser and Burns (1973, 1979, 1981) theory of flux, which postulates that the activity of an enzyme embedded in a multienzyme pathway can sometimes vary from wild-type to very low levels (perhaps 5–10% wild type) with no significant effect on flux through the total pathway.
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    Theoretical and applied genetics 57 (1980), S. 257-266 
    ISSN: 1432-2242
    Keywords: Drosophila ; Ethanol ; Climatic races ; Desiccation ; Development times
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Adult tolerance of ethanol vapour in a closed system containing 12% ethanol in solution, decreases in a cline from southern to northern Australia. However a Darwin population is more tolerant than predicted from its latitude. Ethanol tolerance races in Australia have almost certainly evolved within the last 100–150 years, because of resource unavailability prior to that time. Within populations, variation among isofemale strains is lowest in the climatically extreme southern Melbourne (37°S) and northern Darwin and Melville I. (11–12°S) populations. This suggests low resource diversity within extreme populations compared with the climatically less extreme Brisbane (28°S) and especially Townsville (19°S) populations. For desiccation resistance, the population rankings are: Darwin Melbourne 〉 Townsville 〉 Brisbane Melville I. and for development time, rankings are similar: Darwin Melbourne 〈 Townsville 〈 Brisbane Melville I. Therefore resource utilization heterogeneity is greatest in populations not greatly stressed by desiccation and where development times are extended. In total therefore, the utilization of a diversity of resources is a feature of populations tending somewhat towards a K-strategy; this is emphasized by the relative heterogeneity among isofemale strains of these populations for desiccation resistance and to a lesser extent development times. The D. melanogaster gene pool can be viewed as made up of climate-associated races. Since the ethanol tolerances of adjacent (and climatically similar) Darwin and Melville I. are very different, resource utilization races may occur within climatic races. Such a mosaic of resource utilization races are more likely in climatically extreme than in optimal habitats.
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  • 44
    ISSN: 1617-4623
    Keywords: Drosophila ; Heat shock ; Polymorphism ; Transcript mapping ; Deletion
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    Topics: Biology
    Notes: Summary We have continued the transcriptional analysis of the region of cytological locus 67B that contains the four small heat shock genes and other genes. Transcription from one of the heat shock genes in the region, hsp 26, takes place during high temperature treatment and at certain developmental stages, without heat shock, in several tissues, such as imaginal discs and adult ovaries. Observations of unexpected products after nuclease protection experiments periments provided the first indication of what genomic blot experiments showed to be small deletions. The alleles containing the deletion are expressed at the same level as the wild type allele. The deletion shortens the protein product, implying that it is in the coding region. Furthermore, flies homozygous for one of the deletion alleles are viable.
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    Molecular genetics and genomics 180 (1980), S. 411-418 
    ISSN: 1617-4623
    Keywords: Drosophila ; Vitellogenin ; Female-sterile mutant ; Protein processing
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    Topics: Biology
    Notes: Summary The mutant fs(1) 1163 of Drosophila melanogaster, which was isolated by Gans et al. (1975) is a recessive homozygous female sterile at 18°C and a dominant female — sterile at 29°C. We reported previously that there are reduced quantities of the largest of the three yolk polypeptides in Drosophila melanogaster in the haemolymph and eggs of this mutant at 29°C (Bownes and Hames 1978 a). In this paper we show that the yolk protein defect maps within approximately 2.5 recombination units of the female sterility at 21±2.5 map units on the X-chromosome. The temperature-sensitive period of the yolk protein defect is after emergence. In vitro labelling of fs(1) 1163 ovaries and fat bodies showed that they were able to synthesise yolk polypeptide 1. Interestingly, studies on the proteins present in the various tissues indicate that the fat body tends to accumulate all three yolk polypeptides in the mutant. This phenotype is partially co-dominant in that an effect is seen in heterozygotes as well as homozygotes and is enhanced by increased temperature. This mutant could therefore have a defect (a) in the structural gene for yolk polypeptide 1, (b) in the processing and secretion enzyme systems; (c) in the fat body or all tissues leading to altered secretion properties. Mutants like fs(1) 1163 which alter specific steps in vitellogenesis should be of value for analysing the genetic and biochemical control of the synthesis, transport and sequestering of the yolk polypeptides during oogenesis.
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    Molecular genetics and genomics 205 (1986), S. 557-560 
    ISSN: 1617-4623
    Keywords: Drosophila ; Secretion mutant ; Sequence analysis ; Yolk protein
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    Topics: Biology
    Notes: Summary The female-sterile mutants fs(1) 1163 of Drosophila melanogaster described by Gans et al. (1975) has been characterised as a yolk protein 1 (YP1) secretion mutant (Bownes and Hames 1978b; Bownes and Hodson 1980). We have cloned and sequenced the YP1 gene from this strain, and the strain in which the mutant was induced. One amino acid substitution was found in the predicted polypeptide sequence, an isoleucine to asparagine change at position 92. The sequence of the leader peptide was identical to previously published YP1 sequences. The possible effects of the amino acid change were investigated by computer analysis, which suggests there is no major alteration of secondary structure, but that a hydrophobic region in YP1 is lost in the mutant. This may affect higher order structure.
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    Behavior genetics 16 (1986), S. 307-317 
    ISSN: 1573-3297
    Keywords: assortative mating ; sexual selection ; inbreeding ; polymorphism ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract The hypothesis that negative assortative mating occurs as a mechanism limiting inbreeding between genetically related individuals ofDrosophila melanogaster was tested. In order to avoid bias linked to using inbred lines, experiments made use of the F1 hybrid progeny between lines rendered homozygous on chromosomes 1, 2, and 3. No negative assortative mating was found, but significant additive variation was observed between lines for orientation, vibration, copulation latencies, and copulation duration. There was no consistency of results, either among parameters or between sexes from the same line. It is therefore unlikely that the variations observed are due merely to quantitative differences in “vigor”. Since all lines originated from the same wild population, these differences are a possible estimate of natural variation in sexual behavior.
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    Behavior genetics 16 (1986), S. 407-413 
    ISSN: 1573-3297
    Keywords: Drosophila ; pupation height ; larval behavior ; light
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract A comparison of pupation height in light and dark was made using 12 species ofDrosophila, representing four species groups and four different ecological backgrounds (temperate-montane forest,virilis group desert,replate group; cosmopolitanmelanogaster group; tropical forest,willistoni group). Light condition has a significant effect on pupation height in only two of the species. In the light,D. montana stays close to the food surface, whileD. melanogaster pupates higher in light than in dark. Light-dependent patterns of pupation response do not correspond to those previously reported for the light-dependent mating response. Considerable interspecific variation exists for pupation height in each species triad, some of which could provide a basis for larval niche separation. Patterns of species differences in the desertrepleta triad are the same in light and in darkness.
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    Behavior genetics 10 (1980), S. 237-249 
    ISSN: 1573-3297
    Keywords: Drosophila ; behavior ; ADH activity ; adaptation ; evolution ; alcohol avoidance ; Adh genotypes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Three alcohol dehydrogenase genotypes, homozygous for either the electrophoretically fast, slow, or null allele at theAdh locus inD. melanogaster, were tested for relative larval alcohol preference behavior (APB) over a range of ethanol concentrations. Differences in behavior between genotypes were not significant at concentrations below 10%. At concentrations greater than 10%, avoidance behavior was negatively correlated with the relative ADH activity levels of the genotypes tested. A model based on the differential buildup of toxic acetaldehyde is proposed to explain the avoidance response.
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    Molecular genetics and genomics 204 (1986), S. 302-309 
    ISSN: 1617-4623
    Keywords: Drosophila ; Yolk polypeptides ; Yolk protein genes ; Evolution ; In situ hybridisation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The yolk proteins stored in Drosophila, oocytes for utilisation during embryogenesis are an ideal system for studying the regulation of gene expression during development. The 3 major polypeptides found in yolk in D. melanogaster are synthesised in the fat body and ovarian follicle cells and selectively accumulated by the oocyte during vitellogenesis. In order to understand more about their regulation and the mechanism of uptake, studies on other species are necessary. Three yolk polypeptides have previously been identified in the D. melanogaster sibling species (D. melanogaster, D. simulans, D. mauritiana, D. erecta, D. teissieri, D. orena and D. yakuba). In D. melanogaster three genes located on the X chromosome are known to code for these yolk polypeptides. in this study genomic Southern transfers and in situ hybridisation experiments were carried out on the sibling species. Using the three cloned yolk protein genes from D. melanogaster, homologous sequences could be detected in the sibling species. It is suggested that three yolk protein genes occur in each of these species, all being located on the X chromosome, and that two of the genes are very closely linked in these same species. Yolk protein gene-homologous DNA sequences have also been identified in two more distantly related species D. funebris and D. virilis.
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    Molecular genetics and genomics 205 (1986), S. 483-486 
    ISSN: 1617-4623
    Keywords: Drosophila ; wingless ; Autonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary T(Y;2) translocations were used to cytologically localise the wingless locus of Drosophila melanogaster. We found that an existing T(Y;2), which is an insertion of a segment of 2L into the Y chromosome, has wg + within this insert. This Y chromosome was used to generate an attached XY chromosome containing wg +. The mutation claret-nondisjunctional (ca nd) was used to induce the loss of this XY chromosome and thus generate gynandromorphs with wg 1/wg 1 male tissue and wg +/wg 1/wg 1 female tissue. Analysis of these gynanders demonstrated that a genotypically wingless mutant hemithorax is usually also phenotypically mutant in these half body mosaics; thus wg 1 is discautonomous. This observation is of interest as it is known that wg is not cell autonomous.
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    Molecular genetics and genomics 205 (1986), S. 213-216 
    ISSN: 1617-4623
    Keywords: Drosophila ; Follicle cell ; Protein ; Female sterile ; Mutation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In order to correlate the synthesis of a previously described set of follicel cell (Fc) proteins with a known mutation that affects female fertility, three female sterile mutations, fs(1)384, fs(1)508 and fs(1)1501, mapping in the same region as the Fc locus (7C1-9), were analysed with respect to Fc synthesis. The fs(1)508 strain displayed a normal Fc protein pattern, while in fs(1)384 no Fc protein synthesis could be detected. The fs(1)1501 pattern of Fc polypeptide synthesis was totally different from that of any previously analysed strain, displaying a set of proteins that were much larger than the standard Fc variant form. Two of the female sterile mutations, fs(1)384 and fs(1)1501, were combined in rans with two wild-type strains displaying two different electrophoretic variant forms of the Fc proteins. The combinations were then analysed for Fc protein synthesis, using the fact that females heterozygous for two of the Fc variant forms display both parental forms. The results indicate that the fs(1)384 mutation is directly involved in the synthesis of the Fc proteins, as the trans heterozygotes only synthesize the Fc form derived from the wild-type parent. We also suggest that the large proteins synthesized by the fs(1)1501 mutant are a defective Fc variant form. The nature of the two mutations is also discussed.
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    Cell & tissue research 211 (1980), S. 51-64 
    ISSN: 1432-0878
    Keywords: Cerebral glucose utilization ; Deoxyglucose method ; Dry autoradiography ; Insect brain ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Nervous activity may be localized in anatomical sections of brain tissue by the autoradiographic deoxyglucose technique. The method provides sufficient structural preservation and spatial resolution for detailed functional investigation of complex but small-sized nervous systems when the original technique is modified as follows: (i) use of 3H instead of 14C as radioactive label, (ii) application of labeled deoxyglucose in concentrations close to physiological glucose levels rather than in trace amounts, (iii) stimulation for 4–9 h after deoxyglucose application instead of 20–45 min, (iv) subsequent preparation avoiding aqueous phases at all stages from fixation to autoradiography, and (v) plastic embedding of the tissue such that serial semithin sections of good structural preservation may be routinely cut. Brief aqueous fixation and dehydration at room temperature as has been described for vertebrates apparently cannot preserve stimulus-induced distribution of radioactive label in the brain of the fly Drosophila melanogaster. Aspects of the results that illustrate the potential and some limitations of the present technique are discussed.
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