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dna sequence variation at the period locus within and among species of the drosophila melanogaster complex.a 1.9-kilobase region of the period locus was sequenced in six individuals of drosophila melanogaster and from six individuals of each of three sibling species: drosophila simulans, drosophila sechellia and drosophila mauritiana. extensive genealogical analysis of 174 polymorphic sites reveals a complex history. it appears that d. simulans, as a large population still segregating very old lineages, gave rise to the island species d. mauritiana and d. sechellia. rather than considering these spec ...19938436278
hybrid lethal systems in the drosophila melanogaster species complex. ii. the zygotic hybrid rescue (zhr) gene of d. melanogaster.hybrid females from drosophila simulans females x drosophila melanogaster males die as embryos while hybrid males from the reciprocal cross die as larvae. we have recovered a mutation in melanogaster that rescues the former hybrid females. it was located on the x chromosome at a position close to the centromere, and it was a zygotically acting gene, in contrast with mhr (maternal hybrid rescue) in simulans that rescues the same hybrids maternally. we named it zhr (zygotic hybrid rescue). the gen ...19938436277
hybrid lethal systems in the drosophila melanogaster species complex. i. the maternal hybrid rescue (mhr) gene of drosophila simulans.hybrid females from drosophila simulans females x drosophila melanogaster males die as embryos while hybrid males from the reciprocal cross die as late larvae. the other two classes are sterile adults. letting c, x, and y designate egg cytoplasm, x, and y chromosomes, respectively, and subscripts m and s stand for melanogaster and simulans, cmxmys males are lethal in the larval stage and are rescued by the previously reported genes, lhr (lethal hybrid rescue) in simulans or hmr (hybrid male resc ...19938436276
noninvolvement of the long terminal repeat of transposable element 17.6 in insecticide resistance in drosophila.waters and colleagues recently suggested [waters, l. c., zelhof, a. c., shaw, b. j. & ch'ang, l.-y. (1992) proc. natl. acad. sci. usa 89, 4855-4859] that an insertion of a long terminal repeat of transposable element 17.6 into the 3' untranslated region of a p450 gene leads to susceptibility to the insecticide ddt in drosophila melanogaster. we tested this hypothesis by screening lines from around the world and found that the presence or absence of a long terminal repeat was uncorrelated with re ...19938390673
regulatory aspects of esterase 6 activity variation in sibling drosophila species.esterase 6 in drosophila melanogaster, drosophila simulans and drosophila mauritiana is produced in several life stages and diverse tissues, but the major pulse of expression is in the sperm ejaculatory duct of adult males. comparison of est6 activity levels among several lines of d. melanogaster, d. simulans and d. mauritiana reveals two major quantitative differences among the species. first, newly eclosed females of both d. simulans and d. mauritiana show significantly higher est6 activity th ...19938360077
evidence for adaptive evolution of the g6pd gene in the drosophila melanogaster and drosophila simulans lineages.proponents of the neutral theory argue that evolution at the molecular level largely reflects a process of random genetic drift of neutral mutations. under this theory, levels of interspecific divergence and intraspecific polymorphism are expected to be correlated across classes of nucleotide or amino acid sequences with different degrees of functional constraint, such as synonymous and replacement sites. nucleotide sites with reduced polymorphism should show comparably reduced levels of intersp ...19938356041
the effects of interspecific y chromosome replacements on hybrid sterility within the drosophila simulans clade.we attempted to introgress y chromosomes between three sibling species of drosophila: d. simulans, d. sechellia and d. mauritiana. four d. sechellia y chromosomes were introgressed into d. simulans without loss of fertility whereas the four reciprocal introgressions (d. simulans y introgressed into d sechellia) all result in sterility. both reciprocal y introgressions of d. simulans and d. mauritiana (four of each) also result in sterility. compared with d. simulans males, the males with the d. ...19938244006
a combined classical genetic and high resolution two-dimensional electrophoretic approach to the assessment of the number of genes affecting hybrid male sterility in drosophila simulans and drosophila sechellia.we have attempted to estimate the number of genes involved in postzygotic reproductive isolation between two closely related species, drosophila simulans and drosophila sechellia, by a novel approach that involves the use of high resolution two-dimensional gel electrophoresis (2de) to examine testis proteins in parents, hybrids and fertile and sterile backcross progenies. the important results that have emerged from this study are as follows: (1) about 8% of about 1000 proteins examined showed d ...19938224814
differences in p element population dynamics between the sibling species drosophila melanogaster and drosophila simulans.patterns of p element establishment and evolution were compared in populations of d. melanogaster and d. simulans. for each species, mixed populations were initiated with m strain flies lacking p elements together with p strain flies having similar p element copy numbers and phenotypes. the mixed populations were subsequently maintained under similar environmental conditions. on the basis of gonadal sterility assays, p elements tended to be significantly more active in d. melanogaster than in d. ...19948206365
properties of drosophila simulans strains experimentally infected by different clones of the bacterium wolbachia.maternally inherited bacteria of the genus wolbachia are responsible for reproductive incompatibilities between strains of drosophila simulans. such incompatibilities are known in several types of crosses, including both directions of crossing between two types of infected strains, 'r' and 's'. to determine whether the bidirectional incompatibility between r and s flies is due only to differences between their bacteria, flies from an uninfected strain have been experimentally infected with bacte ...19948200813
analysis of drosophila chromosome 4 using pulsed field gel electrophoresis.previous estimates of the size of drosophila melanogaster chromosome 4 have indicated that it is 1% to 4% of the genome or approximately 6 mb. we have used pulsed field gel electrophoresis (pfge) to separate megabase-sized molecules of d. melanogaster chromosomal dna. southern blots of these gels were probed with dna fragments from the cubitus interruptus and zfh-2 genes, which are located on chromosome 4. they each identify the same-sized distinct band that migrates at approximately 5.2 mb in d ...19938149812
evolutionary inferences from dna variation at the 6-phosphogluconate dehydrogenase locus in natural populations of drosophila: selection and geographic differentiation.several allozyme-coding genes in drosophila melanogaster show patterns suggesting that polymorphisms at these loci are targets of balancing selection. an important question is whether these genes have similar distributions of underlying dna sequence variation which would indicate similar evolutionary processes occurring in this class of loci. one such locus, 6-phosphogluconate dehydrogenase (pgd), has previously been shown to exhibit clinal variation for fast/slow electromorph variation in the u ...19948138153
a single-amino acid substitution in a gamma-aminobutyric acid subtype a receptor locus is associated with cyclodiene insecticide resistance in drosophila populations.resistance to cyclodiene insecticides, documented in at least 277 species, is perhaps the most common kind of resistance to any pesticide. by using cyclodiene resistance to localize the responsible gene, a gamma-aminobutyric acid type a receptor/chloride ion-channel gene was previously cloned and sequenced from an insecticide-susceptible drosophila melanogaster strain. we now describe the molecular genetics of the resistance allele. a single-base-pair mutation, causing a single-amino acid substi ...19938095336
lack of correlation between interspecific divergence and intraspecific polymorphism at the suppressor of forked region in drosophila melanogaster and drosophila simulans.levels of dna sequence polymorphism at the suppressor of forked [su(f)] region in natural populations of drosophila melanogaster and drosophila simulans are estimated by restriction map analysis. su(f) is located at the base of the euchromatic portion of the x chromosome where the level of crossing-over per physical length is extremely low. in a survey of 55 alleles from three natural populations of d. melanogaster, only 2 restriction sites of 27 hexanucleotide and 108 tetranucleotide restrictio ...19938095333
genetic and maternal variation for heat resistance in drosophila from the field.in drosophila, field heritability estimates have focused on morphological traits and ignored maternal effects. this study considers heritable variation and maternal effects in a physiological trait, heat resistance. drosophila were collected from the field in melbourne, australia. resistance was determined using knock-down time at 37 degrees. drosophila melanogaster was more resistant than drosophila simulans, and males tended to be more resistant than females. field heritability and maternal ef ...19948088524
nuclear background affects frequency dynamics of mitochondrial dna variants in drosophila simulans.transplasmic lines, in which the original mitochondrial dna (mtdna) had been completely replaced by the mtdna of the donor, were constructed to test for selection on mtdna variants and to investigate the effects of nuclear-cytoplasmic interactions in drosophila simulans. these lines were used to set up 12 experimental populations putting in competition two mtdna variants with two different starting frequencies. population cages were maintained for 20 generations and periodically sampled to monit ...19948056616
evidence for complex genic interactions between conspecific chromosomes underlying hybrid female sterility in the drosophila simulans clade.f1 hybrid females between the sibling species drosophila simulans, drosophila mauritiana and drosophila sechellia are completely fertile. however, we have found that female sterility can be observed in f2 backcross females who are homozygous for d. simulans x chromosomes and homozygous for autosomal regions from either d. mauritiana or d. sechellia. our results indicate that neither d. mauritiana autosome (2 or 3) can cause complete female sterility in a d. simulans background. the simultaneous ...19948056310
genetics of reproductive isolation in the drosophila simulans clade: complex epistasis underlying hybrid male sterility.we have analyzed the sterility associated with introgressions of the distal one-fourth of the x chromosome from either drosophila mauritiana or drosophila sechellia into the genome of drosophila simulans using a series of visible and dna markers. because in drosophila hybrids, male sterility is usually complete and is often tightly linked with each of several markers used in crosses, a simple genetic basis has generally been assumed. in our low resolution mapping experiment, we were not able to ...19948056308
effects of the fourth chromosome on the sterility of hybrids between drosophila simulans and its relatives.genetic analysis of the fourth chromosome of drosophila simulans shows that it has no effect on either male or female fertility in hybrids with two sibling species, d. mauritiana and d. sechellia. the lack of effect holds even when the d. simulans chromosome is homozygous in a foreign genetic background. the absence of major fourth chromosome "sterility genes" in these hybridizations contrasts with the presence of a fourth-chromosome gene causing complete male sterility in hybrids of the more di ...20078014464
cytoplasmic incompatibility in australian populations of drosophila melanogaster.in drosophila melanogaster, weak incompatibility in crosses between infected and uninfected strains is associated with a wolbachia microorganism. crosses between infected males and uninfected females show a reduction (15-30%) in egg hatch. progeny tests indicated that the infection is widespread in australian d. melanogaster populations and that populations are polymorphic for the presence of the infection. the infection status of 266 lines from 12 populations along the eastern coast of australi ...19948005448
molecular evolution of the metallothionein gene mtn in the melanogaster species group: results from drosophila ananassae.three distinctly different alleles of the metallothionein gene mtn have been identified in natural drosophila melanogaster populations: mtn.3, mtn1, and dp(mtn1), where the latter designates a tandem duplication of mtn1. in drosophila simulans, only mtn.3-type alleles have been found. it has been suggested that mtn.3 is the ancestral allele and demonstrated that a presumed two-step transition from mtn.3 to mtn1 to dp(mtn1) is accompanied by an approximate 5-fold increase in rna levels. we analyz ...19948001781
replacement of the natural wolbachia symbiont of drosophila simulans with a mosquito counterpart.inherited rickettsial symbionts of the genus wolbachia occur commonly in arthropods and have been implicated in the expression of parthenogenesis, feminization and cytoplasmic incompatibility wolbachia from the asian tiger mosquito, aedes albopictus, to replace the natural infection of drosophila simulans by means of embryonic microinjection techniques. the transferred wolbachia infection behaves like a natural drosophila infection with regard to its inheritance, cytoskeleton interactions and ab ...19947906391
a prokaryotic dnaa sequence in drosophila melanogaster: wolbachia infection and cytoplasmic incompatibility among laboratory strains.using oligonucleotide primers derived from the aligned polypeptide sequences of several prokaryotic dnaa genes, we amplified from drosophila melanogaster dna a 557 bp fragment containing a single open reading frame. the predicted peptide sequence shows a significant similarity to previously characterized protein sequences that are encoded by the dnaa genes of several prokaryotes. the dnaa sequences are also detectable by pcr in dna from drosophila simulans and nasonia vitripennis flies which are ...19947894745
nucleotide variation at the hypervariable esterase 6 isozyme locus of drosophila simulans.esterase 6 (est-6/est6) is polymorphic in both drosophila melanogaster and d. simulans for two common allozyme forms, as well as for several other less common variants. parallel latitudinal clines in the frequencies of the common est6-f and est6-s allozymes in these species have previously been interpreted in terms of a shared amino acid polymorphism that distinguishes the two variants and is subject to selection. here we compare the sequences of four d. simulans est-6 isolates and show that ove ...19957877486
unraveling selection in the mitochondrial genome of drosophila.we examine mitochondrial dna variation at the cytochrome b locus within and between three species of drosophila to determine whether patterns of variation conform to the predictions of neutral molecular evolution. the entire 1137-bp cytochrome b locus was sequenced in 16 lines of drosophila melanogaster, 18 lines of drosophila simulans and 13 lines of drosophila yakuba. patterns of variation depart from neutrality by several test criteria. analysis of the evolutionary clock hypothesis shows uneq ...19947851772
neutral and non-neutral evolution of drosophila mitochondrial dna.to test hypotheses of neutral evolution of mitochondrial dna (mtdna), nucleotide sequences were determined for 1515 base pairs of the nadh dehydrogenase subunit 5 (nd5) gene in the mitochondrial dna of 29 lines of drosophila melanogaster and 9 lines of its sibling species drosophila simulans. in contrast to the patterns for nuclear genes, where d. melanogaster generally exhibits much less nucleotide polymorphism, the number of segregating sites was slightly higher in a global sample of nine nd5 ...19947851771
molecular polymorphism in the period gene of drosophila simulans.the threonine-glycine (thr-gly) repeat region of the period (per) gene of eight natural populations of drosophila simulans from europe and north africa was analyzed by polymerase chain reaction, dna sequencing and heteroduplex formation. five different length alleles encoding 21, 23, 25 and two different kinds of 24 thr-gly pairs in the uninterrupted repeat were found. in the 3' region flanking the repeat 6 nucleotide substitutions (3 synonymous, 3 replacement) were observed in three different c ...19947851767
genetics of hybrid male sterility between drosophila sibling species: a complex web of epistasis is revealed in interspecific studies.to study the genetic differences responsible for the sterility of their male hybrids, we introgressed small segments of an x chromosome from drosophila simulans into a pure drosophila mauritiana genetic background, then assessed the fertility of males carrying heterospecific introgressions of varying size. although this analysis examined less than 20% of the x chromosome (roughly 5% of the euchromatic portion of the d. simulans genome), and the segments were introgressed in only one direction, a ...19947828817
meiosis in drosophila males. i. the question of separate conjunctive mechanisms for the xy and autosomal bivalents.the conjunctive mechanism of the xy bivalent is believed to differ from that of the autosomal bivalents in the achiasmate drosophila melanogaster male. it has been proposed that hypothetical cohesive elements, termed collochores, hold the x and y chromosomes together at or near their nucleolar organizing regions (nors) and that collochores are not exhibited by autosomal bivalents. in electron micrographs, unique fibrillar material is observed between the x and y chromosomes at the synaptic site. ...19947821091
the doc transposable element in drosophila melanogaster and drosophila simulans: genomic distribution and transcription.the mobile element doc is similar in structure and coding potential to the line families found in various organisms. in this paper, we analyze the insertional and structural polymorphism of this element and show that it appears to have a long evolutionary history in the genome of d. melanogaster. like the family of i elements, the doc family seems to display three types of elements: full length elements, defective members that have recently transposed and long since immobilized members common to ...19947813908
mating propensity of indian drosophila melanogaster populations with d. simulans: a nonadaptive latitudinal cline.crosses were investigated between a single strain of drosophila simulans and 28 natural indian populations of d. melanogaster. in each case, a mass culture and 10 isofemale lines of d. melanogaster were studied. crosses were much easier between d. melanogaster females and d. simulans males than in the reciprocal case. also, hybrid offspring were easier to obtain by using d. melanogaster flies (either males or females) from isofemale lines than from mass cultures. finally, the crossability, estim ...19957759292
inferring weak selection from patterns of polymorphism and divergence at "silent" sites in drosophila dna.patterns of codon usage and "silent" dna divergence suggest that natural selection discriminates among synonymous codons in drosophila. "preferred" codons are consistently found in higher frequencies within their synonymous families in drosophila melanogaster genes. this suggests a simple model of silent dna evolution where natural selection favors mutations from unpreferred to preferred codons (preferred changes). changes in the opposite direction, from preferred to unpreferred synonymous codon ...19957713409
evidence for a wolbachia symbiont in drosophila melanogaster.the bacterial cell division gene, ftsz, was used as a specific probe to show the presence of a symbiotic bacterium in two wild type strains of drosophila melanogaster. under stringent hybridization conditions we have shown that the bacterium is transferred to the progeny of these strains from infected mothers and can be eradicated by treatment with the antibiotic tetracycline. we have characterized this bacterium, by amplifying and sequencing its 16s rrna gene, as being a member of the genus wol ...19937691685
the reproductive incompatibility system in drosophila simulans: dapi-staining analysis of the wolbachia symbionts in sperm cysts.any hitherto available technique used to detect the presence of wolbachia, a rickettsia-like endosymbiont of drosophila simulans, i.e., crossing with tester strains, electron microscope observations, dapi-staining of embryo, or amplification of specific sequences by pcr are notably time-consuming techniques. staining sperm cysts with the fluorochrome dapi is here shown to be a fast and reliable technique to detect the symbiont and evaluate the level of infection of individual males. wolbachia ce ...19937689622
cloning and characterization of an ftsz homologue from a bacterial symbiont of drosophila melanogaster.a 1194 bp open reading frame that codes for a 398 amino acid peptide was cloned from a lambda gt11 library of drosophila melanogaster genomic dna. the predicted peptide sequence is very similar to three previously characterized protein sequences that are encoded by the ftsz genes in escherichia coli, bacillus subtilis and rhizobium meliloti. the ftsz protein has a major role in the initiation of cell division in prokaryotic cells. using a tetracycline treatment that eradicates bacterial parasite ...19937689140
genetic studies on premating isolation in drosophila simulans. i.ad. simulans line highly crossable with d. melanogaster.the s2 line of drosophila simulans, an isofemale line from a natural population at mishima, japan, was found to have high crossability with d. melanogaster. over 80% of the s2 females mated with d. melanogaster males, while only 2.4- 14.2% of control females from other d. simulans lines mated. the reciprocal mating (d. melanogaster female x s2 males) was in normal range (35-50%). the crossability of the f1 females between the s2 and other normal simulans lines was slightly higher than the contro ...19957632441
evolution of single and double wolbachia symbioses during speciation in the drosophila simulans complex.maternally inherited bacteria of the genus wolbachia are responsible for the early death of embryos in crosses between uninfected females and infected males in several insect species. this phenomenon, known as cytoplasmic incompatibility, also occurs between strains infected by different symbionts in some species, including drosophila simulans. wolbachia was found in two species closely related to d. simulans, drosophila mauritiana, and drosophila sechellia, and shown to cause incompatibility in ...19957604001
malathion resistance levels in sympatric populations of drosophila simulans (diptera: drosophilidae) and d. melanogaster differ by two orders of magnitude.malathion resistance levels were determined in populations of the sympatric species drosophila melanogaster (meigen) and drosophila simulans (sturtevant) from a collection site in tampa bay, fl, with a 20+ yr history of intensive malathion exposure. bioassays of insecticide resistance were done by using a desiccation technique that reduces both the effects of avoidance behavior on the results and the total time of the assay. resistance levels in isofemale lines of d. simulans are as much as 2 or ...19957593892
localization of pheromonal sexual dimorphism in drosophila melanogaster and its effect on sexual isolation.drosophila melanogaster is sexually dimorphic for cuticular hydrocarbons, with males and females having strikingly different profiles of the long-chain compounds that act as contact pheromones. gas-chromatographic analysis of sexual mosaics reveals that the sex specificity of hydrocarbons is located in the abdomen. this explains previous observations that d. melanogaster males display the strongest courtship toward mosaics with female abdomens. we also show that males of the sibling species dros ...19957568163
somatic movement of the mariner transposable element and lifespan of drosophila species.the effect of somatic movement of the mariner transposable element on lifespan was measured in drosophila simulans and drosophila melanogaster males at 25 degrees c. in d. simulans this movement significantly decreased lifespan, whereas in d. melanogaster no correlation between transposon movement and lifespan was found. the results in d. simulans support the hypothesis that somatic genetic damage induced by dna element movement can reduce lifespan.19957565881
cytoplasmic incompatibility in drosophila simulans: dynamics and parameter estimates from natural populations.in drosophila simulans, cytoplasmically transmitted wolbachia microbes cause reduced egg hatch when infected males mate with uninfected females. a wolbachia infection and an associated mtdna variant have spread northward through california since 1986. pcr assays show that wolbachia infection is prevalent throughout the continental us and central and south america, but some lines from florida and ecuador that are pcr-positive for wolbachia do not cause incompatibility. we estimate from natural po ...19957498773
ultrastructural studies on spermatogenesis in a sex-ratio-mutant strain of drosophila simulans.the aberrant sex-ratio mutation in d. simulans used for this study is a temperature-sensitive autosomal recessive. homozygous males raised at 16 degrees c produce about 2% of f1, but those raised at 26 degrees c, have a normal sex ratio. ultrastructural studies of spermatogenesis have revealed many anomalies in the germ cells of flies raised at 16 degrees c, but the same flies raised at 26 degrees c had few anomalies. the earliest spermatogenic stage with noticeable abnormalities was the primary ...19807405869
the satellite dnas of drosophila simulans. 19817333458
genetic variability at the esterase-6 locus in natural populations of drosophila simulans in relation to environmental heterogeneity.the allozymic variation at at the esterase-6 locus examined in fourteen samples of natural populations of drosophila simulans collected in two different localities. the samples were collected from different species of fruits in the two localities and from banana baits located some meters apart from the fruits. the analysis was done by sequential electrophoresis, using varied gel concentrations and buffers. by this technique, we detected 27 alleles at the esterase-6 locus, where only five alleles ...19817327390
crossing-over in the female hybrids between drosophila simulans and drosophila mauritiana.the cross between d. simulans and d. mauritiana yields fertile hybrid females. crossing-over occurs in such female hybrids. this system allows the transfer of pieces of chromosomes from one species into another, thus providing an experimental tool to analyze the genetic basis of evolutionary problems, as well as the regulation of gene expression during development.19827200915
artificial selection for altered male wing display in drosophila simulans. 19827138454
estimation of genetic variability in natural populations of drosophila simulans by two-dimensional and starch gel electrophoresis.genic variation in natural populations of drosophila simulans was surveyed using allozymic and two-dimensional electrophoretic techniques. consistent with some previous reports, allozymic heterozygosity appeared lower than in the sibling species d. melanogaster (0.07 vs. 0.16). no variation was detected by two-dimensional electrophoresis of 19 lines scored for 70 abundant proteins. this is consistent with reported reductions in estimates of genic heterozygosity by two-dimensional electrophoresis ...19827095420
genetic analysis of drosophila vitellogenesis: a molecular weight variant of yolk polypeptide-2 in drosophila simulans. 19806930533
pupation site selection in drosophila simulans. 19836838459
light-dependent pupation site preferences in drosophila. ii. drosophila melanogaster and drosophila simulans.drosophila melanogaster prefers to pupate in the dark, while its sibling species, d. simulans, prefers the light when the species are tested in isolation and when cultured and tested together. reciprocal interspecific hybridizations were carried out and the f1 individuals were tested. progeny from the cross of d. melanogaster females with d. simulans males chose pupations sites exactly intermediate between those of the two parental species, while the reciprocal-cross offspring preferred light pu ...19816803758
determination of some biochemical and structural features of alcohol dehydrogenases from drosophila simulans and drosophila virilis. comparison of their properties with the drosophila melanogaster adhs enzyme.the biochemical properties of the enzyme alcohol dehydrogenase of two different drosophila species, drosophila simulans and drosophila virilis, were studied and compared with those of drosophila melanogaster adhs enzyme. all of them consist of two identical subunits of molecular weight 27800 and share significant similarities in function. the substrate specificities of these enzymes were characterized and km(app.) and vmax.(app.) values were calculated. all these alcohol dehydrogenases show grea ...19816796069
hybrid sterility in drosophila simulans: relationships with the hybrid dysgenesis syndrome in drosophila melanogaster. 19816790477
comparative studies of allozyme loci in drosophila simulans and drosophila melanogaster. i. three dipeptidase loci.genetic variation at three dipeptidase loci (dip-a, dip-b, and dip-c) in drosophila simulans was analyzed by starch gel electrophoresis. dip-a was found to be polymorphic in four populations, while dip-b and dip-c were found to be polymorphic in one. the numbers of different alleles found at each respective locus were: dip-a, two; dip-b, two; and dip-c, three. dip-a was genetically mapped at 57.9 on the second chromosome, and dip-b and dip-c at 80.9 and 87.9 on the third chromosome, respectively ...19816784720
purification and enzyme stability of alcohol dehydrogenase from drosophila simulans, drosophila virilis and drosophila melanogaster adhs.three alcohol dehydrogenases from drosophila simulans, drosophila virillis and drosophila melanogaster adhs (which possesses an alloenzyme with slow electrophoretic mobility) were purified essentially to homogeneity. the purification procedure involves a new step of affinity chromatography, which efficiently lowers the amount of contaminants in the final preparation, producing a very stable enzyme. the purification procedure developed consists of a salmine sulphate precipitation, two cm-sepharos ...19806779810
analysis of courtship sequences of the hybrids between drosophila melanogaster and drosophila simulans.several transitions between sequential male courtship elements were analyzed for drosophila melanogaster, its close relative d. simulans, and two types of hybrid males. hybrid males from special reciprocal crosses did not differ. while d. melanogaster and d. simulans males differed markedly for the majority of transitions studied, hybrid males showed no consistent pattern with the parent species, being indistinguishable from d. simulans males, indistinguishable from d. melanogaster, or intermedi ...19806779788
localization of the ribosomal rna genes in drosophila simulans.in situ hybridization of cloned rrna genes from drosophila melanogaster to d. simulans metaphase chromosomes shows that in the tested wild type strains both sex chromosomes contain a nucleolus organizer region. silver grain counts support the published data that the x chromosomal rrna gene number is significantly higher than the y chromosomal.19806772417
genetic basis of male sterility in hybrids between two closely related species of drosophila.drosophila simulans and drosophila mauritiana are closely related sibling species, the former cosmopolitan and the latter restricted to the small oceanic island of mauritius. genetic analysis of male sterility in hybrids between these species shows that at least five loci (one on each chromosome arm) are responsible for this reproductive isolation. this is the most loci that could have been detected with the techniques used and implies that the true genetic divergence for sterility is even great ...19846589604
olfactory responses to alcohols by adults of sympatric populations of drosophila melanogaster and drosophila simulans. 19846435598
nucleotide sequence comparison of the adh gene in three drosophilids.the alcohol dehydrogenase (adh) gene has been isolated from drosophila simulans and d. mauritiana by screening lambda clone libraries of each with a previously cloned adh gene from d. melanogaster. the isolated lambda clones were subcloned and partially sequenced to determine the relatedness of these species and to examine details of evolutionary change in the structure of the adh gene. we report the sequence of the first 704 nucleotides of each gene as well as 127 bases in the 5' untranslated r ...19846429340
regulatory gene evolution: adaptive differences in expression of alcohol dehydrogenase in drosophila melanogaster and drosophila simulans.in drosophila melanogaster x d. simulans hybrids, the alcohol dehydrogenase (adh) electromorphs characteristic of the two parents display tissue- and stage-specific differences in relative level of expression. this implies distinct cis-acting regulatory elements associated with the respective adh alleles. these cis-acting elements account in part, but not completely, for markedly different overall patterns of adh expression in the two species. the regulatory patterns seem to be adaptively signif ...19846429088
meiosis and early cleavage in drosophila melanogaster eggs: effects of the claret-non-disjunctional mutation.the claret-non-disjunctional (cand) mutation is a female-specific mutation in drosophila melanogaster, which causes a high frequency of mortality (89--90%) in eggs laid by the homozygous females. among the progeny that survive to the adult stage, greater than 50% are aneuploid and/or mosaic for the x and number 4 chromosomes. the genetic studies of cand indicate that it is homologous to the claret mutation (ca-simulans) in drosophila simulans. the cytological effect of the cand mutation on meios ...19836413518
variation in response to co2 in drosophila melanogaster and d. simulans.a type of slow-recovery from high temperature co2 exposure is a wild-type characteristic of drosophila simulans. species hybrids of wild-type d. melanogaster and d. simulans have intermediate recovery times. the response to nitrogen exposure at both high and low temperatures is the same for the two species suggesting that the observed co2 response is more than just anoxia. since there is no female bias in hybrids, and since injections of d. simulans extract into d. melanogaster produced no incre ...20136408161
the 5s ribosomal genes in the drosophila melanogaster species subgroup. nucleotide sequence of a 5s unit from drosophila simulans and drosophila teissieri.the 5s genes of the eight species of the d. melanogaster subgroup have been mapped. the spacers, in contrast with coding regions, differ markedly between most species. one 5s gene unit has been sequenced for both d. simulans and d. teissieri. the mature 5s rna region in these two species is identical to the corresponding region of d. melanogaster. only 5 nucleotide variations occur between the d. melanogaster and d. simulans 5s gene spacers. the spacer in d. teissieri is very different. only two ...19846320111
intraspecific diversity of nucleotide sequences within the adenine + thymine-rich region of mitochondrial dna molecules of drosophila mauritiana, drosophila melanogaster and drosophila simulans.mitochondrial dna (mtdna) molecules from drosophila mauritiana, d. melanogaster, and d. simulans contain a single adenine + thymine (a+t)-rich region, which is similarly located in all molecules, but varies in size among these species. using agarose gel electrophoresis and electron microscopy, a difference in occurrence of one ecori site, and a difference in size (approximately 0.7 kb) of the a+t-rich regions was found between mtdna molecules of flies of two female lines of d. mauritiana. in het ...19806258143
origin and direction of replication in mitochondrial dna molecules from the genus drosophila.mitochondrial dna (mtdna) obtained from ovaries of drosophila simulans, d. mauritiana, d. takahashii, d. yakuba and d. virilis was examined by electron microscopy. from a consideration of the structural properties of replicative intermediates, it was concluded that in mtdna molecules of each species, synthesis on one strand can be up to 97% complete before synthesis on the complementary strand is initiated. mtdna molecules of each species contain a single a+t-rich region which shows species-spec ...19806253922
interspecific dna transformation in drosophila.a dna fragment that includes the wild-type rosy (ry+) gene of drosophila melanogaster has been introduced by microinjection into the germ line of the reproductively isolated species drosophila simulans and incorporated into the d. simulans genome. transformation was mediated by the transposable element p, which occurs in the genome of most natural populations of d. melanogaster but not in d. simulans. rubin and spradling [rubin, g.m. & spradling, a.c. (1982) science 218, 348-353] have previously ...19846095302
an abnormal sex ratio in drosophila simulans. 19676035593
the genetics of an acid phosphatase in drosophila melanogaster and drosophila simulans. 19665919327
the effects of artificial selection for slow mating in drosophila simulans. i. the behavioural changes. 19685639888
unequal proportions of dna complementary to ribosomal rna in males and females of drosophila simulans. 19665229971
the effects of artificial selection for slow mating in drosophila simulans. ii. genetic analysis of the slow mating line. 19715156614
a stablizing interaction between the founder effect and interdeme mixing in competing populations of drosophila melanogaster and drosophila simulans. 19724622476
[development of sexual dimorphism as an expression of gene est-6 in the ontogenesis of drosophila melanogaster and drosophila simulans]. 20064217999
dispersal activities of the sibling species drosophila melanogaster and drosophila simulans. 19734201482
studies of a homologous gene-enzyme system, esterase c, in drosophila melanogaster and drosophila simulans. 19734197378
chromosome variation within drosophila simulans detected by quinacrine staining. 19714109035
differences in the quinacrine staining of the chromosomes of a pair of sibling species: drosophila melanogaster and drosophila simulans. 19714106800
enzymatic and quantitative variation in european and african populations of drosophila simulans.allozyme polymorphism at 15 loci of d. simulans was studied in 7 natural populations from europe, north and tropical africa. morphological traits were studied in nine european and eleven afrotropical strains. within a population, the biochemical polymorphisms of drosophila simulans and its sibling drosophila melanogaster are not very different, although d. simulans has a lower heterozygosity. between-populations genetic differentiation is however much lower in d. simulans than in d. melanogaster ...19854008274
a further characterization of drosophila cuticular monoenes using a mass spectrometry method to localize double bonds in complex mixtures.positions of double bonds of olefins of complex mixtures, such as those of drosophila cuticular hydrocarbons, have been determined using a simple method combining methoxymercuration-demercuration of extracts and analysis by gas chromatography-mass spectrometry using ammonia for chemical ionization. chemical similarities between cuticular monoenes of both sexes of drosophila simulans and males of drosophila melanogaster are specified: the major isomer is always in position 7.19853923860
location of an x-linked factor causing sterility in male hybrids of drosophila simulans and d. mauritiana.we report the first mapping of a genetic factor responsible for reproductive isolation: a small segment of genome strongly affecting sperm motility in hybrids between the sibling species drosophila simulans and d. mauritiana. maximum-likelihood analysis of data from ten generations of backcrossing places this factor at 1.1 +/- 0.2 map units from the forked locus, at position 54.9 +/- 0.2 or 57.1 +/- 0.2 on the x chromosome.19863781872
courtship behavior and the kinetics of mating in three lines of drosophila simulans and their hybrids. 19873606537
linkage disequilibrium in experimental populations of drosophila simulans: a test of the random drift hypothesis. 19873443289
sexual isolation and courtship behavior in drosophila simulans, d. mauritiana, and their interspecific hybrids. 19883377736
organization and evolution of the alcohol dehydrogenase gene in drosophila.the alcohol dehydrogenase (adh) gene was isolated from drosophila simulans and d. mauritiana, and the dna sequence of a 4.6-kb region, containing the structural gene and flanking sequence, was determined for each. these sequences were compared with the adh region of d. melanogaster to characterize changes that occur in the drosophila genome during evolution and to identify conserved sequences of functional importance. drosophila simulans and d. mauritiana adh are organized in a manner similar to ...19883367783
drosophila s virus, a hereditary reolike virus, probable agent of the morphological s character in drosophila simulans.isometric reolike virions were found in all the examined drosophila simulans flies from two strains (simes-st and israel-st) presenting the s phenotype, a maternally inherited morphological trait (abnormalities of bristles). normal flies of both strains appeared virus-free. virions were found in the cytoplasm of male and female gonads and epidermal cells, including the bristle-forming cells, which appeared disorganized. steps of virogenesis were described. a positive correlation was demonstrated ...19883346947
natural populations of drosophila simulans show great uniformity of the mitochondrial dna restriction map.the mitochondrial dna of 21 drosophila simulans isofemale lines of different geographic origins was digested with seven restriction endonucleases. all the lines, with one exception for one line and one enzyme, showed the same restriction patterns. the results confirm previous investigations showing great uniformity of the mtdna genome in d. simulans.19883215515
differing amounts of genetic polymorphism in testes and male accessory glands of drosophila melanogaster and drosophila simulans.we surveyed genetic polymorphism by two-dimensional gel electrophoresis of male reproductive tract proteins in 20 isofemale lines each of drosophila melanogaster and drosophila simulans. after classifying 244 such proteins of drosophila melanogaster and 271 of drosophila simulans by their distribution between testes and accessory glands within the reproductive tract, significant correlations were found between genetic polymorphism and tissue distribution. in both species, gland-specific proteins ...19883132149
extensive microheterogeneity of serine trna genes from drosophila melanogaster.the nucleotide sequences of nine genes corresponding to trna(ser)4 or trna(ser)7 of drosophila melanogaster were determined. eight of the genes compose the major trna(ser)4,7 cluster at 12de on the x chromosome, while the other is from 23e on the left arm of chromosome 2. among the eight x-linked genes, five different, interrelated, classes of sequence were found. four of the eight genes correspond to trna(ser)4 and trna(ser)7 (which are 96% homologous), two appear to result from single crossove ...19873126300
physiological significance of the alcohol dehydrogenase polymorphism in larvae of drosophila.this study deals with biochemical and metabolic-physiological aspects of the relationship between variation in in vivo alcohol dehydrogenase activity and fitness in larvae homozygous for the alleles adh71k, adhf, adhs, of drosophila melanogaster, and for the common adh allele of drosophila simulans. the adh genotypes differ in the maximum oxidation rates of propan-2-ol into acetone in vivo. there are smaller differences between the adh genotypes in rates of ethanol elimination. rates of accumula ...19873117619
identical satellite dna sequences in sibling species of drosophila.the evolution of simple satellite dnas was examined by dna-dna hybridization of ten drosophila melanogaster satellite sequences to dnas of the sibling species, drosophila simulans and drosophila erecta. seven of these repeat types are present in tandem arrays in d. simulans and each of the ten sequences is repeated in d. erecta. in thermal melts, six of the seven satellite sequences in d. simulans and seven of the ten sequences in d. erecta melted within 1 deg.c of the corresponding values in d. ...19873112413
contrasting patterns of geographic variation in the cosmopolitan sibling species drosophila melanogaster and drosophila simulans.an electrophoretic study was carried out to compare the geographic pattern of genetic variation in drosophila simulans with that of its sibling species, drosophila melanogaster. an identical set of 32 gene-protein loci was studied in four geographically distant populations of d. simulans and two populations of d. melanogaster, all originating from europe and africa. the comparison yielded the following results: tropical populations of d. simulans were, in terms of the number of unique alleles, a ...19873107542
interspecific genetic control of courtship song production and reception in drosophila.the genetic control of courtship song differences between drosophila melanogaster and drosophila simulans males was investigated by producing hybrids from reciprocal crosses. the song rhythm difference between the parental species appears to be due to sex-linked genes, whereas the basic interpulse-interval difference is autosomally inherited. hybrid females show selective preferences for artificially generated songs carrying intermediate "hybrid" characteristics.19863083506
nucleotide sequence of a retrotransposon 297 isolated from drosophila simulans. 19863025817
molecular analysis of p element behavior in drosophila simulans transformants.in this report we describe the successful transformation of drosophila simulans with an autonomous p element from drosophila melanogaster without the use of a selectable marker. this result demonstrates that there is no species barrier for p element transposition. utilizing gel blotting and in situ hybridization techniques, we have monitored the behavior of newly-introduced p elements in several d. simulans transformed lines over twelve generations. in most instances, an overall increase in the ...19852993820
drosophila s virus is a member of the reoviridae family.the s character of drosophila simulans, the absence or malformation or both of bristles and other cuticular structures, was described by comendador (drosophila inf. serv. 55:26-28, 1980). its characteristics (maternal transmission, low pathogenicity, and sensitivity to temperature) suggested the existence of a virus as the causative agent. indeed, reoviruslike particles were found in subcuticular cells of s individuals, and its association with s phenotypic expression was shown. this virus was c ...19892911113
mitochondrial dna variability in drosophila simulans: quasi absence of polymorphism within each of the three cytoplasmic races.nucleotide variability of mtdna extracted from 144 isofemale lines collected in the whole range of d. simulans was analysed with 10-15 restriction enzymes and 73 lines were studied using one or a few enzymes. all clones were distributed into 3 mitochondrial genomes, sii, siii and siiii. these types are allopatric and can define geographic races. mixed populations occur only in madagascar and réunion, where siii and siiii are found together. among 40 sites detected with 10 enzymes, the variabilit ...19882906636
the rosy region of drosophila melanogaster and drosophila simulans. i. contrasting levels of naturally occurring dna restriction map variation and divergence.a 40-kb region around the rosy and snake loci was analyzed for restriction map variation among 60 lines of drosophila melanogaster and 30 lines of drosophila simulans collected together at a single locality in raleigh, north carolina. dna sequence variation in d. simulans was estimated to be 6.3 times greater than in d. melanogaster (heterozygosities per nucleotide of 1.9% vs. 0.3%). this result stands in marked contrast to results of studies of phenotypic variation including proteins (allozymes ...20092900794
genetics of an unstable white mutant in drosophila simulans: reversion, suppression and somatic instability.a spontaneous white mutation, white-milky (wmky) of drosophila simulans is moderately unstable and is associated with a 16-kb long dna insertion into the white gene. wmky, which is an unstable mutation found in d. simulans, has been genetically analyzed. among nine spontaneous, partial reversions toward wild type, five were white locus mutations. they are phenotypically different from each other and three show eye color sexual dimorphism indicating a failure of the dosage compensation mechanism. ...19882842227
maternally inherited transposon excision in drosophila simulans.a mutation in the white gene of drosophila mauritiana resulting from insertion of the transposable element mariner exhibits genetic instability in germline and somatic cells. the instability is greatly enhanced in the presence of the trans-acting autosomal factor mos, giving eye-color mosaics with pigmented sectors of tissue on an otherwise peach-colored background. the mos factor, when introduced into the genome of the sibling species drosophila simulans, exhibited a dramatic maternal effect on ...19882832948
transposable and nontransposable elements similar to the i factor involved in inducer-reactive (ir) hybrid dysgenesis in drosophila melanogaster coexist in various drosophila species.the i factor is a transposable element controlling inducer-reactive (ir) hybrid dysgenesis in drosophila melanogaster, which occurs when males from the class of inducer strains are crossed with females from the class of reactive strains. inducer strains contain several copies of the complete 5.4-kilobase (kb) i factor at various sites on the chromosomal arms; reactive strains contain no complete i factor. incomplete and defective i elements occur at constant locations in pericentromeric heteroch ...20102829216
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