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PubMed1985

Purification and molecular characterization of alcohol dehydrogenase from Drosophila hydei: conservation in the biochemical features of the enzyme in several species of Drosophila.

Alcohol dehydrogenase (ADH) has been purified from Drosophila hydei. Biochemical investigations show that the native enzyme is a dimer consisting of two identical subunits with molecular weight 27,000. The pH optimum values of pure enzyme preparations are 7.9 and 9.4. The pI values are 8.83 and 8.41. Substrate specificities have been characterized. Km(app) values are lowest for propan-2-ol and butan-2-ol and Vmax(app) values are highest for these two substrates. The amino acid composition has been determined. Peptide mapping experiments performed after trypsin digestion of the enzyme allow the identification of 24 peptides. Peptides comprising 64% of the amino acid residues have also been purified by high-performance liquid chromatography (HPLC), and their N-terminal residues and amino acid composition determined. Results are compared with the amino acid sequence of ADH from D. melanogaster Adhs [Thatcher, D. R. (1980). Biochem. J. 187:875]. When data on the biochemical and structural characterization of ADH from D. hydei are compared with data from other species of Drosophila, clear homologies are observed.

Alcohol Oxidoreductases↗
PubMed1976

Behavior genetics of olfactory responses in Drosophila. I. Olfactometry and strain differences in Drosophila melanogaster.

A simple olfactometer was constructed for measuring the responses of adult Drosophila to odoriferous substances, and an index (attractability index, AI) is proposed to evaluate the response. Five strains of Drosophila melanogaster of different geographic origins were tested for their responses to five chemical attractants: ethyl alcohol, acetic acid, lactic acid, ethyl acetate, and n-butyraldehyde. Statistical analysis has shown that the differences of AI among strains are highly significant for all the odorants except acetic acid and that male flies are, in general, less sensitive than females. The number of flies which were inactive in the olfactometer also varied with strain, sex, and odorant, suggesting the involvement of some other behaviors, and this raises some difficulties in interpreting the heterogeneities of AI. Nevertheless, these results suggest that a considerable amount of genetic variation for olfactory response exists in natural population of D. melanogaster.

Acetates↗
PubMed2003

Spatiotemporal calcium signaling in a Drosophila melanogaster cell line stably expressing a Drosophila muscarinic acetylcholine receptor.

A muscarinic acetylcholine receptor (mAChR), DM1, expressed in the nervous system of Drosophila melanogaster, has been stably expressed in a Drosophila S2 cell line (S2-DM1) and used to investigate spatiotemporal calcium changes following agonist activation. Carbamylcholine (CCh) and oxotremorine are potent agonists, whereas application of the vertebrate M1 mAChR agonist, McN-A-343, results in a weak response. Activation of S2-DM1 receptors using CCh resulted in an increase in intracellular calcium ([Ca(2+)](i)) that was biphasic. Two distinct calcium sources were found to contribute to calcium signaling: (1) internal stores that are sensitive to both thapsigargin and 2-aminoethoxydiphenyl borate and (2) capacitative calcium entry. Spatiotemporal imaging of individual S2-DM1 cells showed that the CCh-induced [Ca(2+)](i) transient resulted from a homogeneous calcium increase throughout the cell, indicative of calcium release from internal stores. In contrast, ionomycin induced the formation of a "calcium ring" at the cell periphery, consistent with external calcium influx.

Animals↗
PubMed2005

Hybrid disadvantage in the larval foraging behaviour of the two neotropical species of Drosophila pavani and Drosophila gaucha.

Flies from two populations of the Chilean endemic neotropical species Drosophila pavani and two populations of its sibling species Drosophila gaucha were crossed reciprocally to obtain intra- and interspecific hybrids. The developmental pathways of locomotor activity and feeding rate were analysed for eleven of twelve possible genotype groups. The hybrids showed reduced fitness indicated by a decrease in the measured traits. Hybrid disadvantage was strongest in interspecific hybrids, especially with respect to feeding behaviour. This evidence supports the contention that D. pavani and D. gaucha have evolved different coadapted gene pools controlling the developmental pathways for behavioural traits expressed during larval foraging; but genetic divergence affecting these behaviours has also taken place between locally adapted populations within each species.

Animals↗
PubMed2006

Quantitative genetics of speciation: additive and non-additive genetic differentiation between Drosophila madeirensis and Drosophila subobscura.

The role of dominance and epistasis in population divergence has been an issue of much debate ever since the neoDarwinian synthesis. One of the best ways to dissect the several genetic components affecting the genetic architecture of populations is line cross analysis. Here we present a study comparing generation means of several life history-traits in two closely related Drosophila species: Drosophila subobscura, D. madeirensis as well as their F1 and F2 hybrids. This study aims to determine the relative contributions of additive and non-additive genetic parameters to the differentiation of life-history traits between these two species. The results indicate that both negative dominance and epistatic effects are very important in the differentiation of most traits. We end with considerations about the relevance of these findings for the understanding of the role of non-additive effects in speciation.

Animals↗
PubMed2005

Sexual isolation and cuticular hydrocarbon differences between Drosophila santomea and Drosophila yakuba.

Drosophila santomea and Drosophila yakuba are two sister species inhabiting Saõ Tomé island. Previous studies showed that both species display strong reproductive isolation, although they can produce a few viable hybrids. Our study tried to understand the mechanism of this ethological isolation between two allopatric strains. A strong sexual isolation was confirmed, with a marked asymmetry. Comparisons of latency times to either courtship or copulation suggest that males do not discriminate females, whereas D. yakuba females, but not D. santomea females, accept their homospecifics more quickly. Cuticular hydrocarbon compositions of both species and sexes were also established with gas chromatography (GC) and GC/mass spectrometry analysis. All have (Z)-7-tricosene as their major compound. There are several quantitative differences between species for few minor compounds. The largest difference concerns n-heneicosane, which is more abundant in D. santomea than in D. yakuba flies (up to seven times more between males). A similar quantitative difference was also found in a pair of sympatric strains. Furthermore, D. yakuba males artificially perfumed with n-heneicosane were discriminated negatively by D. yakuba females, suggesting a role for this compound in the sexual isolation between these two species.

Alkenes↗
PubMed1990

Aneuploidy in Drosophila, I. Genetic test systems in the female Drosophila melanogaster for the rapid detection of chemically induced chromosome gain and chromosome loss.

An account is provided of two genetic schemes in the Drosophila melanogaster female designed as rapid detectors of chemically induced aneuploidy, including both chromosome gain and chromosome loss. One scheme is referred to as FIX, in which the female carried free (heterozygously) inverted X (chromosomes) and the other, ZESTE, where females do not carry inversions and the X-linked sexually dimorphic zeste mutation plays the key role in the detection of aneuploid offspring. The principle attribute of the FIX system is that all euploid offspring are wild-type for body and eye color whereas aneuploid females have a yellow body and aneuploid males white eyes; int he ZESTE system all euploid individuals are wild-type for eye color, aneuploid females possess zeste-colored eyes and aneuploid males white eyes. In addition induced polyploidies (2X:2A gametes) appear as yellow and zeste male intersexes in the FIX and ZESTE systems, respectively. In this way all aneuploids are recognized immediately. Consequently, detection of compounds with weak effects requiring large sample sizes may be made in a fraction of the time associated with more traditional schemes for aneuploidy detection in Drosophila.

Aneuploidy↗
PubMed1990

Location of Drosophila C virus target organs in Drosophila host population by an immunofluorescence technique.

Using the immunofluorescence technique we attempted to locate, in the Drosophila host, Drosophila C virus (DCV) target organs after injection of adult flies. Two kinds of organs were infected: those which play a role in reproductive function, including the fat body and follicular cells, and other, including thoracic muscle fibers, tracheal cells, and the digestive tract. These organs correspond to those found in previous tests. Fat body proteins of a DCV-free host population seemed to cross-react with antivirus C antibody. This immune response depended on the origin of the host population. It is known that, when DCV is ingested from the first larval instar, it may have beneficial effects upon host development and reproduction. As DCV has a narrow host spectrum, it is suggested that it is well adapted to its natural host. Hypotheses are proposed to explain how the host resists viral infection and may in fact benefit from such an infection.

Animals↗
PubMed1996

The Drosophila gene alien is expressed in the muscle attachment sites during embryogenesis and encodes a protein highly conserved between plants, Drosophila and vertebrates.

We have found a novel gene (alien) that is expressed exclusively in the muscle attachment sites (apodemes) during embryogenesis in Drosophila. Antibodies raised against the Alien protein enable us to follow the developing attachments from state 11/12 until stage 16/17. The coding region of the Drosophila alien gene is highly conserved to a gene of unknown function, isolated from a plant (Loo et at., 1995), and to the human TRIP15 gene (Lee et al., 1995). Searching for thyroid receptor interacting proteins, TRIP15 was isolated as a negative regulator. Whether there is a functional correlation to Alien remains to be analyzed. Alien expression is independent of muscle formation, as shown in rolling stone mutant embryos. Even in twist and snail mutants, lacking mesodermal development, alien expression is fairly normal, showing a rather autonomous development of the apodemes. The conservation of alien suggests an important role in differentiation.

ATPases Associated with Diverse Cellular Activitie↗
PubMed1997

Trans-activation by the Drosophila myb gene product requires a Drosophila homologue of CBP.

Attempts to demonstrate trans-activation activity by the Drosophila myb gene product (D-Myb) have been unsuccessful so far. We demonstrate that co-transfection of Schneider cells with a plasmid expressing the Drosophila homologue of transcriptional co-activator CBP (dCBP) results in transactivation by D-Myb. Using this assay system, the functional domains of D-Myb were analyzed. Two domains located in the N-proximal region, one of which is required for DNA binding and the other for dCBP binding, are both necessary and sufficient for trans-activation. In this respect, D-Myb is similar to c-Myb and A-Myb, but different from mammalian B-Myb. These results shed light on how the myb gene diverged during the course of evolution.

Animals↗
PubMed1996

Wild-type and insecticide-resistant homo-oligomeric GABA receptors of Drosophila melanogaster stably expressed in a Drosophila cell line.

RDL is an ionotropic GABA receptor subunit, a product of the Rdl gene, originally identified in the Maryland strain of Drosophila melanogaster. Here, we report the generation of a Drosophila melanogaster cell line (S2-RDLA302S) stably expressing a mutated, dieldrin-resistant (A302S) form of RDL. The properties of this dieldrin-resistant, homo-oligomeric receptor have been compared with those of the stably expressed, wild-type form (S2-RDL). Using these stable lines, a striking reduction in sensitivity to both picrotoxinin and dieldrin was observed for responses to GABA of S2-RDLA302S compared to S2-RDL. To determine if these stable insect cell lines generate results similar to those obtained by transient expression in Xenopus laevis oocytes, we have examined the actions of two widely used convulsants, EBOB and TBPS, and a recently developed convulsant BIDN, on RDL-mediated GABA responses in the two expression systems. In both oocytes and S2 cells, the three convulsants suppressed the amplitude of responses to GABA. Thus, in accord with earlier work on agonist and allosteric sites, the S2-RDL cell line is found to yield similar pharmacological results to those obtained in transient expression studies. Stable cell lines are now available expressing susceptible and resistant forms of an ionotropic receptor by GABAergic insecticides.

Animals↗
PubMed1996

Molecular organization of the alcohol dehydrogenase loci of Drosophila grimshawi and Drosophila hawaiiensis.

To determine sequences involved in conserved and species-specific aspects of alcohol dehydrogenase (Adh) gene expression in Hawaiian Drosophila, a 3644-base pair (bp) region containing the D. grimshawi gene and the homologous 3335-bp region containing the D. hawaiiensis Adh gene were sequenced. These genes have the two-promoter and exon-intron structure seen for many Drosophila Adh genes. Analysis of putative and known regulatory sequences of the D. grimshawi and D. hawaiiensis genes in comparison to those of D. affinidisjuncta (the only other Hawaiian species for which the promoter organization is known) highlighted elements likely to be involved in conserved aspects of Adh gene expression as well as sequences that may account for species-specific differences in tissue-specific expression. Sequence comparisons, in the context of regulatory roles previously assigned to particular gene fragments, indicated that multiple insertions and deletions in the promoter regions are responsible for differences in tissue-specific regulation displayed by these genes.

Alcohol Dehydrogenase↗
PubMed1991

Wrinkling of the eye in hybrids between Drosophila virilis and Drosophila lummei is caused by interaction of maternal and zygotic genes.

Hybrids of Drosophila virilis females and Drosophila lummei males have visible developmental anomalies in external adult structures. Reciprocal hybrids are normal, and the anomalies are not found in other interspecific F1 hybrids of the virilis subgroup. Antibiotic treatments with ampicillin, streptomycin and tetracycline did not cure the syndrome. The genetic basis of the wrinkling of the compound eye was analysed in detail. Both male and female F1 progeny of D. virilis mothers were affected, indicating that wrinkling of eyes is maternally determined. F1 hybrid females produced healthy progeny. Backcross hybrid females (D. virilis x F1) with 16 different combinations of autosomes, either heterozygous or homozygous for D. virilis, were crossed with D. lummei males. It was found that homozygous D. virilis chromosomes 2 and 5 together were necessary to induce the maternal effect. The hybrid zygote responded to the maternal effect when the chromosomes 2, 4 and/or 5 were heterozygous. Elimination of the small sixth (dot) chromosome of D. lummei from the hybrids was correlated with the wrinkling of eyes, but was not the cause, as the two phenomena had a different genetic basis and temperature response. Furthermore, the eyes were wrinkled in flies which presumably had had no D. lummei dot chromosome to lose.

Animals↗
PubMed1996

Incompatibilities between Y chromosome and autosomes are responsible for male hybrid sterility in crosses between Drosophila virilis and Drosophila texana.

Crosses between Drosophila virilis and D. texana produce viable and fertile F1 males and females. When F1 males are backcrossed to either parental species they also produced fertile sons. However, about one-third of F1 males carrying the D. texana Y chromosome are sterile. When fertile F1 males with the D. texana Y chromosome are crossed to D. virilis, about three quarters of the sons are sterile. We show that these sterilities result from incompatibilities between the D. texana Y chromosome and at least two of the D. virilis autosomes. X/Y incompatibilities can be excluded in this pair of species, and X/autosome incompatibilities appear to be either absent or to play a minor role in the sterility of male progeny from backcrosses of F1 males to females from either species. It is suggested that Y/autosome incompatibilities may be among the first to appear in the development of postzygotic isolation in Drosophila.

Animals↗
PubMed2004

Wing shape heritability and morphological divergence of the sibling species Drosophila mercatorum and Drosophila paranaensis.

The fruit-flies Drosophila paranaensis and Drosophila mercatorum pararepleta are sibling species belonging to the repleta group. Females of these two species are normally considered to be morphologically indistinguishable while males only differ consistently in the morphology of their genitalia. These species are sympatric throughout a large area of their geographic distribution. In this study, we investigated the degree of morphological divergence between D. paranaensis and D. mercatorum pararepleta based on morphometric analysis of their wings. The ellipse method was used to describe the placement of the longitudinal and transversal wing veins as well as the size of the wing and the shape of its outline. The heritability under laboratory and field conditions was also estimated from the parameters generated. Multivariate analysis showed that wing morphology possessed sufficient differences to discriminate between the two species with a successful classification rate of 95-98% for females and 82-87% for males. The results of the autoclassification were confirmed by a cross-validation test for females (92-96%). Most measurements possessed significant natural heritability (a mean of 0.48 for D. mercatorum and 0.88 for D. paranaensis), indicating that the variation observed was related to differences in genes acting additively. The principal difference between the two species was in the placement of the posterior transverse wing vein. However, the pattern of morphological variation in the wings of both species was similar, possibly because of shared restrictions in wing development pathways.

Animals↗
PubMed1984

Cloned Drosophila alcohol dehydrogenase genes are correctly expressed after transfection into Drosophila cells in culture.

We have obtained correct transcription of the cloned alcohol dehydrogenase (Adh) gene of Drosophila melanogaster after DNA-mediated gene transfer into Drosophila cells in culture. Supercoiled plasmids, each containing various regions of the Adh gene cloned in pBR327, were introduced into Schneider line 2 (SL2) cells by the calcium phosphate-DNA transfection technique. Although these cells do not normally express their endogenous Adh genes, they do express the exogenous genes as shown by primer extension and nuclease S1 analyses of RNA isolated 48 hr after transfection. The resulting alcohol dehydrogenase (ADH) transcripts, both the larval and adult types, have the correct 5' ends and are properly spliced. The transfected cells have also acquired ADH enzyme activity. The levels of enzyme activity and of ADH protein crossreacting material in cells transfected with different Adh plasmids correlate directly with the level of ADH transcripts. When a mutant Adh gene cloned from an ADH-negative mutant fly with a defect in the splicing of ADH RNA is transfected into the Schneider line 2 cells, the resulting ADH RNA is not spliced properly and there is no synthesis of ADH; thus, the mutant gene transfection into cell culture mimics the mutant phenotypes observed in the mutant fly.

Alcohol Dehydrogenase↗
PubMed1985

Transcription of Drosophila small hsp-tk hybrid genes is induced by heat shock and by ecdysterone in transfected Drosophila cells.

Hybrid genes containing the 5' region of Drosophila heat shock protein (hsp) genes, ligated to the herpesvirus thymidine kinase (tk) gene, were transfected into Drosophila line S3 cells. Constructions containing sequences upstream from hsp70, or from any of the small hsp genes, showed heat-inducible tk expression. Ecdysterone-inducible tk expression was seen only in transfections with small hsp-tk hybrid genes. Plasmids containing a synthetic "heat shock consensus sequence" or a deletion of the hsp23 upstream region were totally inactive in transfection studies.

Animals↗
PubMed1989

A long interspersed repetitive element--the I factor of Drosophila teissieri--is able to transpose in different Drosophila species.

Long interspersed repetitive elements (LINEs) are transposable elements present in many species. In mammals they are difficult to study because most of them are defective and their transposition frequency is low. The I factor of Drosophila melanogaster is a LINE element that is particularly interesting because its transposition occurs at high frequency during I-R hybrid dysgenesis. This phenomenon occurs when males from the class of inducer strains are crossed with females from the class of reactive strains. Inducer strains contain several complete 5.4-kilobase I factors at various sites on the chromosomal arms. Reactive strains are devoid of complete I factors. Many results indicate that active I factors have invaded the D. melanogaster genome recently. To study the evolutionary history of I elements, we have cloned and sequenced a potentially active I factor from Drosophila teissieri. It is flanked by a target-site duplication and terminates at the 3' end by tandem repeats of the sequence TAA. When introduced into the germ line of a reactive strain of D. melanogaster by P element-mediated transformation, it is able to transpose and induces hybrid dysgenesis. This strengthens the hypothesis of a recent reinvasion of the D. melanogaster genome by active I factors giving rise to the inducer strains. They could have originated by horizontal transfer from another species. Such events also could occur for other LINE elements and might explain the spread of new variants in mammalian genomes. Moreover, the results give a further insight into I factor functional organization.

Amino Acid Sequence↗