Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| quantitative trait loci and interaction effects responsible for variation in female postmating mortality in drosophila simulans and d. sechellia introgression lines. | mating appears to inflict a cost to drosophila females, resulting in a reduction of their lifespan shortly after mating. males from different chromosome extracted lines differ significantly in their detrimental effects on postmating female survival, and seminal fluid proteins produced in the male accessory glands are at least partially responsible for the effect. this suggests that there is a genetic basis underlying the male inflicted effect on female's postmating mortality. however, the genes ... | 2005 | 15354189 |
| differential fitness of mitochondrial dna in perturbation cage studies correlates with global abundance and population history in drosophila simulans. | mitochondria are often referred to as the powerhouse of the cell. however, research linking intraspecific differences in organismal fitness with genotypic mitochondrial dna (mtdna) variation has been hampered by the lack of variation in experimentally tractable species. this study examines whether fly lines harbouring three distinct drosophila simulans mtdna types (sii, -ii and -iii) exhibit differential fitness in laboratory perturbation cages. comparison of the pre-perturbation and post-pertur ... | 2004 | 15306370 |
| genetic architecture of wing morphology in drosophila simulans and an analysis of temperature effects on genetic parameter estimates. | the drosophila wing has been used as a model to investigate the mechanisms responsible for size and shape changes in nature, since such changes might underlie morphological evolution. to improve the understanding of wing morphological variation and the interpretation of genetic parameters estimates, we have established 59 lines from a drosophila simulans laboratory population through single pair random matings. the offspring of each line were reared at three different temperatures, and the wing ... | 2004 | 15305171 |
| linking phylogenetics with population genetics to reconstruct the geographic origin of a species. | reconstructing ancestral geographic origins is critical for understanding the long-term evolution of a species. bayesian methods have been proposed to test biogeographic hypotheses while accommodating uncertainty in phylogenetic reconstruction. however, the problem that certain taxa may have a disproportionate influence on conclusions has not been addressed. here, we infer the geographic origin of drosophila simulans using 2,014 bp of the period locus from 63 lines collected from 18 countries. w ... | 2004 | 15288072 |
| quantitative trait loci for sexual isolation between drosophila simulans and d. mauritiana. | sexual isolating mechanisms that act before fertilization are often considered the most important genetic barriers leading to speciation in animals. while recent progress has been made toward understanding the genetic basis of the postzygotic isolating mechanisms of hybrid sterility and inviability, little is known about the genetic basis of prezygotic sexual isolation. here, we map quantitative trait loci (qtl) contributing to prezygotic reproductive isolation between the sibling species drosop ... | 2004 | 15280240 |
| sex-ratio distorter of drosophila simulans reduces male productivity and sperm competition ability. | the aim of the present study was to determine whether the effects of sex-ratio segregation distorters on the fertility of male drosophila simulans can explain the contrasting success of these x-linked meiotic drivers in different populations of the species. we compared the fertility of sex-ratio and wild-type males under different mating conditions. both types were found to be equally fertile when mating was allowed, with two females per male, during the whole period of egg laying. by contrast s ... | 2004 | 15271073 |
| bacteriophage flux in endosymbionts (wolbachia): infection frequency, lateral transfer, and recombination rates. | the highly specialized genomes of bacterial endosymbionts typically lack one of the major contributors of genomic flux in the free-living microbial world-bacteriophages. this study yields three results that show bacteriophages have, to the contrary, been influential in the genome evolution of the most prevalent bacterial endosymbiont of invertebrates, wolbachia. first, we show that bacteriophage wo is more widespread in wolbachia than previously recognized, occurring in at least 89% (35/39) of t ... | 2004 | 15254259 |
| wolbachia and cytoplasmic incompatibility in mosquitoes. | wolbachia are maternally inherited bacteria that induce cytoplasmic incompatibility in mosquitoes, and are able to use these patterns of sterility to spread themselves through populations. for this reason they have been proposed as a gene drive system for mosquito genetic replacement, as well as for the reduction of population size or for modulating population age structure in order to reduce disease transmission. here, recent progress in the study of mosquito wolbachia is reviewed. we now have ... | 2004 | 15242714 |
| molecular population genetics of male accessory gland proteins in the drosophila simulans complex. | accessory gland proteins are a major component of drosophila seminal fluid. these proteins have a variety of functions and may be subject to sexual selection and/or antagonistic evolution between the sexes. most population genetic data from these proteins are from d. melanogaster and d. simulans. here, we extend the population genetic analysis of acp genes to the other simulans complex species, d. mauritiana and d. sechellia. we sequenced population samples of seven acp's from d. mauritiana, d. ... | 2004 | 15238524 |
| [structural organization and distribution of symbiotic bacteria wolbachia in early embryos and ovaries of drosophila melanogaster and d. simulans]. | electron microscopic and morphometric analyses of wolbachia distribution in early embryos of drosophila flies have demonstrated that the number of bacteria in the embryo remains constant from fertilization to blastoderm, and that afterwards the symbionts could be observed only in the polar cells. each bacterium has a three-layer envelope, makes contacts with microtubules and moves through the cytoplasm following the actively dividing nuclei. it has been found for the first time that wolbachia co ... | 2004 | 15214166 |
| strain-specific quantification of wolbachia density in aedes albopictus and effects of larval rearing conditions. | the density of the endosymbiont wolbachia can influence the expression of the crossing sterilities known as cytoplasmic incompatibility (ci), and also its rate of maternal transmission. aedes albopictus mosquitoes contain a superinfection with the wolbachia strains walba and walbb. a strain-specific real-time quantitative pcr assay was developed and used to quantify relative wolbachia strain densities within individual mosquitoes. the walbb strain was consistently found to be at higher density t ... | 2004 | 15157232 |
| nucleotide variation and recombination along the fourth chromosome in drosophila simulans. | the fourth chromosome of drosophila melanogaster and its sister species are believed to be nonrecombining and have been a model system for testing predictions of the effects of selection on linked, neutral variation. we recently examined nucleotide variation along the chromosome of d. melanogaster and revealed that a low average level of recombination could be associated with considerably high levels of nucleotide variation. in this report, we further investigate the variation along the fourth c ... | 2004 | 15126398 |
| evolutionary genetics: mobile dnas as sources of adaptive change? | mobile dnas are potent sources of mutation in wild populations, but seem only rarely to have been used in adaptive evolution. a new study has revealed a mobile dna insertion in drosophila simulans that is associated with an apparent selective sweep and an elevation in expression level of an adjacent gene which creates insecticide resistance. | 2004 | 15120086 |
| why there is a one-way crossability between d. melanogaster and d. simulans? an ontogenic explanation. | in the drosophila melanogaster complex, females d. melanogaster mate relatively easily with males drosophila simulans but the reciprocal cross is rare. the species sexual isolation is mainly based on chemical and acoustic signal exchanges between partners. the male side of this communication is investigated in this paper in order to understand the asymmetry. in d. melanogaster the acoustic signature is highly significant, and is synergistically reinforced by the chemical signal. in d. simulans t ... | 2004 | 15088667 |
| a new hybrid rescue allele in drosophila melanogaster. | crosses of drosophila melanogaster females to males of its sibling species drosophila simulans, drosophila mauritiana and drosophila sechellia produce no sons and daughters that are viable only at low temperatures. we describe here a novel rescue allele df(1)ep307-1-2 isolated on the basis of its suppression of high temperature hybrid female lethality. df(1)ep307-1-2 also rescues hybrid males to the pharate adult stage, the same stage at which it is lethal to d. melanogaster pure species males. ... | 2004 | 15088664 |
| genetics of hybrid inviability and sterility in drosophila: dissection of introgression of d. simulans genes in d. melanogaster genome. | interspecific crosses between drosophila melanogaster and drosophila simulans usually produce sterile unisexual hybrids. the barrier preventing genetic analysis of hybrid inviability and sterility has been taken away by the discovery of a d. simulans strain which produces fertile female hybrids. d. simulans genes in the cytological locations of 21a1 to 22c1-23b1 and 30f3-31c5 to 36a2-7 have been introgressed into the d. melanogaster genetic background by consecutive backcrosses. flies heterozygo ... | 2004 | 15088663 |
| the nature of genetic variation in sex and reproduction-related genes among sibling species of the drosophila melanogaster complex. | much is known about the biology of drosophila melanogaster. as a model organism, a comprehensive understanding of its development, physiology and reproduction has been acquired. as a result, a broad variety of transferable genetic tools and information has allowed sibling species of the d. melanogaster complex to emerge as an important speciation model system. by comparing d. melanogaster with its close relative, drosophila simulans, as well as its other sibling species, we are beginning to unde ... | 2004 | 15088662 |
| a mutation in drosophila simulans that lengthens the circadian period of locomotor activity. | the length of the thr-gly repeat within the period gene of drosophilids, coevolves with its immediate flanking region to maintain the temperature compensation of the fly circadian clock. in drosophila simulans, balancing selection appears to maintain a polymorphism in this region, with three repeat lengths carrying 23, 24 or 25 thr-gly pairs, each in complete linkage disequilibrium with a distinctive flanking region amino acid moiety. we wondered whether separating a specific length repeat from ... | 2004 | 15088660 |
| molecular analysis of circadian clocks in drosophila simulans. | the drosophila simulans per gene is polymorphic for the length of a repeat that encodes a series of thr-gly pairs. we have examined the circadian behaviour of flies derived from isofemale lines that carry the major variants, and find some significant differences in the way that the clock responds to temperature challenge, that might relate to the observed frequencies of these alleles in nature. we also observe that circadian thermal behaviour is also predictably influenced by subtle differences ... | 2004 | 15088659 |
| ecological and genetic interactions in drosophila-parasitoids communities: a case study with d. melanogaster, d. simulans and their common leptopilina parasitoids in south-eastern france. | drosophila species are attacked by a number of parasitoid wasps, which constitute an important factor of population regulation. since drosophila melanogaster and drosophila simulans share common parasitoid species, their ecology and evolution can hardly be understood without considering parasitoids. after a short review of data available on drosophila-parasitoid interactions involving d. melanogaster and d. simulans as hosts, we report field and laboratory experiments investigating the ecologica ... | 2004 | 15088657 |
| mitotic and polytene chromosomes: comparisons between drosophila melanogaster and drosophila simulans. | this review deals with the differences between drosophila melanogaster and drosophila simulans in their mitotic and polytene chromosomes. the description of the mitotic karyotypes of d. melanogaster and d. simulans is mainly based on the methods that allow to differentiate their euchromatin from their heterochromatin: banding patterns, distribution of satellite dnas and location of the rdna. the polytene chromosomes karyotypes are known for many years to differ by a major paracentric inversion o ... | 2004 | 15088654 |
| wanderings of hobo: a transposon in drosophila melanogaster and its close relatives. | the transposon hobo is present in the genomes of drosophila melanogaster and drosophila simulans (and d. mauritiana and probably d. sechellia, based on southern blots) as full-size elements and internally deleted copies. the full-size melanogaster, simulans and mauritiana hobo elements are 99.9% identical at the dna sequence level, and internally deleted copies in these species essentially differ only in having deletions. in addition to these, hobo-related sequences are present and detectable wi ... | 2004 | 15088653 |
| transposable element dynamics in two sibling species: drosophila melanogaster and drosophila simulans. | transposable elements (tes) in the two sibling species, drosophila melanogaster and d. simulans, differ considerably in amount and dynamics, with d. simulans having a smaller amount of tes than d. melanogaster. several hypotheses have been proposed to explain these differences, based on the evolutionary history of the two species, and claim differences either in the effective size of the population or in genome characteristics. recent data suggest, however, that the higher amount of tes in d. me ... | 2004 | 15088652 |
| a reanalysis of protein polymorphism in drosophila melanogaster, d. simulans, d. sechellia and d. mauritiana: effects of population size and selection. | comparison of synonymous and nonsynonymous variation/substitution within and between species at individual genes has become a widely used general approach to detect the effect of selection versus drift. the sibling species group comprised of two cosmopolitan (drosophila melanogaster and drosophila simulans) and two island (drosophila mauritiana and drosophila sechellia) species has become a model system for such studies. in the present study we reanalyzed the pattern of protein variation in thes ... | 2004 | 15088651 |
| the sex-ratio trait and its evolution in drosophila simulans: a comparative approach. | sex-ratio x chromosomes, which prevent the production of y-bearing sperm, have been identified in a dozen drosophila species covering a wide phylogenetic range. it has not yet been established whether the same ancestral genetic system underlies this type of meiotic drive across the genus, but the biological characteristics and the evolutionary history of species undoubtedly determine the fate of x-linked drivers. the intragenomic conflict they trigger contributes to geographical variation in d. ... | 2004 | 15088650 |
| patterns of microsatellite variability in the drosophila melanogaster complex. | forty-seven microsatellite loci were amplified in drosophila melanogaster, drosophila simulans, drosophila mauritiana and drosophila sechellia. the two cosmopolitan species d. melanogaster and d. simulans were found to be the most variable ones, followed by d. mauritiana and d. sechellia. a model based clustering algorithm was applied to the population samples of d. melanogaster, d. simulans and d. sechellia. no evidence for population substructure was detected within species--most likely due to ... | 2004 | 15088648 |
| drosophila melanogaster, drosophila simulans: so similar yet so different. | during the last two decades, the two cosmopolitan species drosophila melanogaster and drosophila simulans have been compared with regard to numerous characteristics, ranging from their geographic distribution and ecology to their dna polymorphism. various traits have been compared, including morphology, physiology, sexual behavior, allozymes and other proteins, chromosomal inversions, mitochondrial and nuclear dna, transposable elements, wolbachia etc. such comparisons reveal similarities and di ... | 2004 | 15088643 |
| signature of selective sweep associated with the evolution of sex-ratio drive in drosophila simulans. | in several drosophila species, the xy mendelian ratio is disturbed by x-linked segregation distorters (sex-ratio drive). we used a collection of recombinants between a nondistorting chromosome and a distorting x chromosome originating from the seychelles to map a candidate sex-ratio region in drosophila simulans using molecular biallelic markers. our data were compatible with the presence of a sex-ratio locus in the 7f cytological region. using sequence polymorphism at the nrg locus, we showed t ... | 2004 | 15082554 |
| do quantitative trait loci (qtl) for a courtship song difference between drosophila simulans and d. sechellia coincide with candidate genes and intraspecific qtl? | the genetic architecture of traits influencing sexual isolation can give insight into the evolution of reproductive isolation and hence speciation. here we report a quantitative trait loci (qtl) analysis of the difference in mean interpulse interval (ipi), an important component of the male courtship song, between drosophila simulans and d. sechellia. using a backcross analysis, we find six qtl that explain a total of 40.7% of the phenotypic variance. three candidate genes are located in the int ... | 2004 | 15082549 |
| molecular evolution of x-linked accessory gland proteins in drosophila pseudoobscura. | in drosophila melanogaster and drosophila simulans, positive darwinian selection drives high rates of evolution of male reproductive genes, and accessory gland proteins (acps) in particular. here, we tested whether 13 x-linked male-specific genes, 4 acps and 9 non-acps, are under selective forces in the drosophila pseudoobscura species group, much as those in the d. melanogaster group. we observed a statistically significant correlation in relative rates of nonsynonymous evolution between the tw ... | 2004 | 15073226 |
| patterns of microsatellite variability among x chromosomes and autosomes indicate a high frequency of beneficial mutations in non-african d. simulans. | we analyzed microsatellite variability at 42 x-linked and 39 autosomal loci from african and european populations of drosophila simulans. the african d. simulans harbored significantly more microsatellite variability than the european flies. in the european population, x-linked polymorphism was more reduced than autosomal variation, whereas there was no significant difference between chromosomes in the african population. previous studies also observed a similar pattern but failed to distinguish ... | 2004 | 15044592 |
| common pattern of evolution of gene expression level and protein sequence in drosophila. | sequence divergence scaled by variation within species has been used to infer the action of selection upon individual genes. applying this approach to expression, we compared whole-genome whole-body rna levels in 10 heterozygous drosophila simulans genotypes and a pooled sample of 10 d. melanogaster lines using affymetrix genechip. for 972 genes expressed in d. melanogaster, the transcript level was below detection threshold in d. simulans, which may be explained either by sequence divergence be ... | 2004 | 15034135 |
| [multiple allelism of the net gene in drosophila melanogaster and drosophila simulans]. | the net gene mutations are known to cause abnormal pattern of veining in all wing regions except for the first posterior cells. in natural populations of drosophila melanogaster, the net alleles were identified, which differ in phenotypic expression from standard mutations. the mutants net-extra-analis from a population belokurikha-2000 have only a single additional vein in the third posterior cell. a line from chernobyl-1986 population have another nontypical allele netch86 and shows a lower de ... | 2003 | 14964828 |
| anomalies in the expression profile of interspecific hybrids of drosophila melanogaster and drosophila simulans. | when females of drosophila melanogaster and males of drosophila simulans are mated, the male progeny are inviable, whereas the female progeny display manifold malformations and are sterile. these abnormalities result from genetic incompatibilities accumulated since the time the lineages of the species diverged, and may have their origin in aberrant gene transcription. because compensatory changes within species may obscure differences at the regulatory level in conventional comparisons of the ex ... | 2004 | 14962989 |
| the genetics of mating recognition between drosophila simulans and d. sechellia. | during courtship, visual and chemical signals are often exchanged between the sexes. the proper exchange of such signals ensures intraspecific recognition. we have examined the genetic basis of interspecific differences in male mating behaviour and pheromone concentration between drosophila simulans and d. sechellia by using drosophila simulans/d. sechellia introgression lines. our results show a majority of quantitative trait loci (qtls) explaining variation in both male mating behaviour and ph ... | 2003 | 14768896 |
| patterns of evolutionary constraints in intronic and intergenic dna of drosophila. | we develop methods to infer levels of evolutionary constraints in the genome by comparing rates of nucleotide substitution in noncoding dna with rates predicted from rates of synonymous site evolution in adjacent genes or other putatively neutrally evolving sites, while accounting for differences in base composition. we apply the methods to estimate levels of constraint in noncoding dna of drosophila. in introns, constraint (the estimated fraction of mutations that are selectively eliminated) is ... | 2004 | 14762063 |
| allometric and nonallometric components of drosophila wing shape respond differently to developmental temperature. | phenotypic plasticity of wing size and shape of drosophila simulans was analyzed across the entire range of viable developmental temperatures with procrustes geometric morphometric method. in agreement with previous studies, size clearly decreases when temperature increases. wing shape variation was decomposed into its allometric (24%) and nonallometric (76%) components, and both were shown to involve landmarks located throughout the entire wing blade. the allometric component basically revealed ... | 2003 | 14761056 |
| strong selective sweep associated with a transposon insertion in drosophila simulans. | we know little about several important properties of beneficial mutations, including their mutational origin, their phenotypic effects (e.g., protein structure changes vs. regulatory changes), and the frequency and rapidity with which they become fixed in a population. one signature of the spread of beneficial mutations is the reduction of heterozygosity at linked sites. here, we present population genetic data from several loci across chromosome arm 2r in drosophila simulans. a 100-kb segment f ... | 2004 | 14745026 |
| wolbachia transfer from rhagoletis cerasi to drosophila simulans: investigating the outcomes of host-symbiont coevolution. | wolbachia is an endosymbiont of diverse arthropod lineages that can induce various alterations of host reproduction for its own benefice. cytoplasmic incompatibility (ci) is the most common phenomenon, which results in embryonic lethality when males that bear wolbachia are mated with females that do not. in the cherry fruit fly, rhagoletis cerasi, wolbachia seems to be responsible for previously reported patterns of incompatibility between populations. here we report on the artificial transfer o ... | 2004 | 14711652 |
| influence of two wolbachia strains on population structure of east african drosophila simulans. | drosophila simulans is hypothesized to have originated in continental east africa or madagascar. in this study, we investigated evolutionary forces operating on mitochondrial dna (mtdna) in populations of d. simulans from zimbabwe, malawi, tanzania, and kenya. variation in mtdna may be affected by positive selection, background selection, demographic history, and/or any maternally inherited factor such as the bacterial symbiont wolbachia. in east africa, the wri and wma wolbachia strains associa ... | 2003 | 14704179 |
| a mariner-like element with a 5' lesion in drosophila simulans. | the unstable white-s2 (ws2) allele of the white gene occurred spontaneously in the s2 strain of drosophila simulans. this mutation was caused by insertion of the submariner element, a mariner-like element with an abnormal tandem duplication of the 5' inverted terminal repeat (itr). although it has an incomplete itr, submariner excises efficiently. the rate of somatic reversion, estimated by the number of eye-color mosaic flies, was 79.9%, and the reversion frequency in the germline was 0.6%. the ... | 2003 | 14686602 |
| genetic dissection of hybrid incompatibilities between drosophila simulans and d. mauritiana. iii. heterogeneous accumulation of hybrid incompatibilities, degree of dominance, and implications for haldane's rule. | the genetic basis of haldane's rule was investigated through estimating the accumulation of hybrid incompatibilities between drosophila simulans and d. mauritiana by means of introgression. the accumulation of hybrid male sterility (hms) is at least 10 times greater than that of hybrid female sterility (hfs) or hybrid lethality (hl). the degree of dominance for hms and hl in a pure d. simulans background is estimated as 0.23-0.29 and 0.33-0.39, respectively; that for hl in an f1 background is un ... | 2003 | 14686533 |
| sequential evolution of a symbiont inferred from the host: wolbachia and drosophila simulans. | this study aims to unravel the biogeography of a model symbiont/host system by exploiting the prediction that a symbiont will leave a signature of infection on the host. specifically, a global sample of 1,442 drosophila simulans from 33 countries and 64 sampling localities was employed to infer the phylogeography of the maternally inherited alpha-proteobacteria wolbachia. phylogenetic analyses, from three symbiont genes and 24 mtdna genomes (excluding the a + t-rich region), showed that each of ... | 2004 | 14660690 |
| [random amplified polymorphic dna (rapd) analysis of drosophila simulans in the mainland of china]. | the widespread distribution of drosophila simulans in the mainland of china was found recently. random amplified polymorphic dna (rapd) was used to analyzed dna polymorphisms of 38 drosophila simulans populations collected from the mainland of china. the origins of d. simulans in china were also discussed. using 40 arbitary primers (10 bp), we made pcr amplifications under the optimized reaction conditions for rapd that had been established in our laboratory. our molecular phylogenetic tree cons ... | 2003 | 14579539 |
| large-scale adaptive hitchhiking upon high recombination in drosophila simulans. | natural selection is expected to leave a characteristic footprint on neighboring nucleotide variation through the effects of genetic linkage. the size of the region affected is proportional to the strength of selection and greatly reduced with the recombinational distance from the selected site. thus, the genomic footprint of selection is generally believed to be restricted to a small dna stretch in normal and highly recombining regions. here, we study the effect of selection on linked polymorph ... | 2003 | 14573496 |
| conservation and divergence of the genetic structure of larval foraging behaviour in two species of the drosophila simulans clade. | larvae of the sibling species drosophila simulans and d. mauritiana have rates of locomotor and feeding activity that are closely similar. comparisons of the trait means for intra- and interspecific hybrids show that significant epistatic interactions affect both characters when the genomes of the two species are combined. the phenotypic variances of progenies obtained by backcrossing the interspecific hybrids to their respective parent species show that appreciable genetic turnover affecting fo ... | 2004 | 14508499 |
| chromosomal monomorphism in brazilian and argentine populations of drosophila simulans and drosophila repleta. | 1964 | 14239802 | |
| pseudotumors and fitness in drosophila melanogaster and drosophila simulans. | 1961 | 13722547 | |
| genetics of drosophila simulans male mating discrimination in crosses with d. melanogaster. | the genetic bases of sexual isolation between drosophila melanogaster and d. simulans have been mainly studied in females, and there is little information about the role of the males in interspecific mating discrimination. using d. simulans synthetic lines with compound chromosomes from a population of the seychelles islands (high frequency of interspecific mating) and a multimarker strain (low frequency), we show that d. simulans males play an important role in discriminating d. melanogaster fe ... | 2003 | 12939619 |
| natural selection drives drosophila immune system evolution. | evidence from disparate sources suggests that natural selection may often play a role in the evolution of host immune system proteins. however, there have been few attempts to make general population genetic inferences on the basis of analysis of several immune-system-related genes from a single species. here we present dna polymorphism and divergence data from 34 genes thought to function in the innate immune system of drosophila simulans and compare these data to those from 28 nonimmunity gene ... | 2003 | 12930753 |
| genetic dissection of hybrid incompatibilities between drosophila simulans and d. mauritiana. ii. mapping hybrid male sterility loci on the third chromosome. | hybrid male sterility (hms) is a rapidly evolving mechanism of reproductive isolation in drosophila. here we report a genetic analysis of hms in third-chromosome segments of drosophila mauritiana that were introgressed into a d. simulans background. qualitative genetic mapping was used to localize 10 loci on 3r and a quantitative trait locus (qtl) procedure (multiple-interval mapping) was used to identify 19 loci on the entire chromosome. these genetic incompatibilities often show dominance and ... | 2003 | 12930748 |
| genetic dissection of hybrid incompatibilities between drosophila simulans and d. mauritiana. i. differential accumulation of hybrid male sterility effects on the x and autosomes. | the genetic basis of hybrid incompatibility in crosses between drosophila mauritiana and d. simulans was investigated to gain insight into the evolutionary mechanisms of speciation. in this study, segments of the d. mauritiana third chromosome were introgressed into a d. simulans genetic background and tested as homozygotes for viability, male fertility, and female fertility. the entire third chromosome was covered with partially overlapping segments. many segments were male sterile, while none ... | 2003 | 12930747 |
| sperm chromatin remodelling and wolbachia-induced cytoplasmic incompatibility in drosophila. | wolbachia pipientis is an obligate bacterial endosymbiont, which has successfully invaded approximately 20% of all insect species by manipulating their normal developmental patterns. wolbachia-induced phenotypes include parthenogenesis, male killing, and, most notably, cytoplasmic incompatibility. in the future these phenotypes might be useful in controlling or modifying insect populations but this will depend on our understanding of the basic molecular processes underlying insect fertilization ... | 2003 | 12897857 |
| sex-dependent gene expression and evolution of the drosophila transcriptome. | comparison of the gene-expression profiles between adults of drosophila melanogaster and drosophila simulans has uncovered the evolution of genes that exhibit sex-dependent regulation. approximately half the genes showed differences in expression between the species, and among these, approximately 83% involved a gain, loss, increase, decrease, or reversal of sex-biased expression. most of the interspecific differences in messenger rna abundance affect male-biased genes. genes that differ in expr ... | 2003 | 12805547 |
| genetic studies on premating isolation in drosophila simulans. ii. a d. simulans line highly crossable to males of d. yakuba and d. teissieri. | females of the s1 line of drosophila simulans, an isofemale line from a natural population at mishima, japan, were found to show high crossability to males of d. yakuba and d. teissieri. with d. yakuba males, 24.0-58.5% of the s1 females were inseminated, while the rate was only 0.0-6.3% for the control lines. the high crossability was ascribed to the genes on the x and third chromosomes. with d. teissieri males, 38.0-51.5% of the s1 females were inseminated, while the rate was only 0.0-6.2% for ... | 2003 | 12773816 |
| mitochondrial genotype affects fitness in drosophila simulans. | drosophila simulans is known to harbor three distinct mitochondrial dna (mtdna) haplotype groups (sii, -ii, and -iii) with nearly 3.0% interhaplotypic divergence but <0.06% intrahaplotypic diversity. with the large amount of genetic variation in this system, the potential power to detect intraspecific fitness differences in fly lines that carry distinct haplotypes is great. we test three life-history traits on fly lines with known sequence differences in the mtdna genome after controlling the nu ... | 2003 | 12750331 |
| variability on the dot chromosome in the drosophila simulans clade. | a recent study suggested that recent nuclear gene introgression between drosophila simulans and d. mauritiana may have obscured efforts to estimate the phylogeny of the species of the d. simulans clade, which includes these two species and d. sechellia. here, we report sequence variation of an intron of the eyeless gene in this species group. this gene should introgress freely between these species because it is not linked to any known barriers to gene exchange. we have also reevaluated levels o ... | 2003 | 12733664 |
| the evolution of autosomal suppressors of sex-ratio drive in drosophila simulans. | sex-ratio drive, which results in males siring female-biased progeny, has been reported in several drosophila species, including d. simulans. it is caused by x-linked drivers that prevent the production of y-bearing sperm. in natural populations of d. simulans, the drivers are usually cryptic, because their spread has elicited the evolution of drive suppressors. we investigated autosomal suppression in flies from madagascar, réunion and kenya. autosomal suppressors were found in all three places ... | 2003 | 12656572 |
| cloning and characterization of a gene encoding glutathione-regulated potassium-efflux system protein kefkl from the endosymbiont wolbachia. | the maternally inherited intracellular symbiont wolbachia is well known for inducing a variety of reproductive and developmental abnormalities in the diverse arthropod hosts it infects. it has been implicated in causing cytoplasmic incompatibility (ci), parthenogenesis, feminization of genetic males and male killing in different hosts. however, the molecular mechanisms by which this fastidious bacterium causes these abnormalities have not yet been determined. in our study, representational diffe ... | 2002 | 12652910 |
| worldwide distribution of transposable element copy number in natural populations of drosophila simulans. | transposable elements (tes), which promote various kinds of mutations, constitute a large fraction of the genome. how they invade natural populations and species is therefore of fundamental importance for understanding the dynamics of genetic diversity and genome composition. on the basis of 85 samples of natural populations of drosophila simulans, we report the distributions of the genome insertion site numbers of nine tes that were chosen because they have a low average number of sites. most p ... | 2003 | 12643577 |
| patterns of dna sequence polymorphism at sod vicinities in drosophila melanogaster: unraveling the footprint of a recent selective sweep. | we survey dna sequence polymorphisms at the sod locus and four neighboring regions of drosophila melanogaster, spanning 55,513 base pairs (bp), in 15 strains from a natural population, plus one reference laboratory strain and one strain of drosophila simulans. our objective is to characterize a proposed selective sweep that occurred at a locus close to sod in d. melanogaster and to characterize the strength of the selection event, its time, and the size of the hitchhiked region. two regions, 181 ... | 2003 | 12578968 |
| the evolutionary history of drosophila buzzatii. xxxiv. the distribution of the retrotransposon osvaldo in original and colonizing populations. | the frequency distribution of the retrotransposon osvaldo in the haploid genome of drosophila buzzatii has been studied in five natural populations from the iberian peninsula and six natural populations from argentina. in iberian populations, osvaldo insertion sites do not follow a poisson distribution, most probably due to eight euchromatic sites with high occupancy, found in all populations. the estimated alpha and beta parameters, which measure the relative importance of drift and negative se ... | 1998 | 12572617 |
| wolbachia distribution and cytoplasmic incompatibility during sperm development: the cyst as the basic cellular unit of ci expression. | the growth and distribution of the intracellular microbe wolbachia pipientis during spermatogenesis in several different host/symbiont genetic combinations in drosophila melanogaster and drosophila simulans is described. considerable intra- and inter-strain variation in wolbachia density and tissue distribution was observed. wolbachia were found inside spermatocytes and spermatids or within the somatic cyst cells surrounding the germ cells. some strains displayed both tissue distributions. high ... | 2003 | 12559491 |
| evolution of gene expression in the drosophila melanogaster subgroup. | little is known about broad patterns of variation and evolution of gene expression during any developmental process. here we investigate variation in genome-wide gene expression among drosophila simulans, drosophila yakuba and four strains of drosophila melanogaster during a major developmental transition--the start of metamorphosis. differences in gene activity between these lineages follow a phylogenetic pattern, and 27% of all of the genes in these genomes differ in their developmental gene e ... | 2003 | 12548287 |
| genomic effects of nucleotide substitutions in drosophila simulans. | selective fixation of beneficial mutations reduces levels of linked, neutral variation. the magnitude of this "hitchhiking effect" is determined by the strength of selection and the recombination rate between selected and neutral sites. thus, depending on the values of these parameters and the frequency with which directional selection occurs, the genomic scale over which directional selection reduces levels of linked variation may vary widely. here we present a permutation-based analysis of nuc ... | 2002 | 12524346 |
| superinfection of laodelphax striatellus with wolbachia from drosophila simulans. | wolbachia are maternally inherited, intracellular alpha-proteobacteria that infect a wide range of arthropods. they manipulate the reproduction of hosts to facilitate their spread into host populations, through ways such as cytoplasmic incompatibility (ci), parthenogenesis, feminization and male killing. the influence of wolbachia infection on host populations has attracted considerable interest in their possible role in speciation and as a potential agent of biological control. in this study, w ... | 2003 | 12522428 |
| characterization of non-cytoplasmic incompatibility inducing wolbachia in two continental african populations of drosophila simulans. | wolbachia is an endocellular bacterium infecting arthropods and nematodes. in arthropods, it invades host populations through various mechanisms, affecting host reproduction, the most common of which being cytoplasmic incompatibility (ci). ci is an embryonic mortality occurring when infected males mate with uninfected females or females infected by a different wolbachia strain. this phenomenon is observed in drosophila simulans, an intensively studied wolbachia host, harbouring at least five dis ... | 2003 | 12522425 |
| sex-ratio drive in drosophila simulans: variation in segregation ratio of x chromosomes from a natural population. | the sex-ratio trait that exists in a dozen drosophila species is a case of naturally occurring x chromosome drive that causes males to produce female-biased progeny. autosomal and y polymorphism for suppressors are known to cause variation in drive expression, but the x chromosome polymorphism has never been thoroughly investigated. we characterized 41 x chromosomes from a natural population of drosophila simulans that had been transferred to a suppressor-free genetic background. we found two cl ... | 2002 | 12454068 |
| evolution of wolbachia-induced cytoplasmic incompatibility in drosophila simulans and d. sechellia. | the intracellular bacterium wolbachia invades arthropod host populations through various mechanisms, the most common of which being cytoplasmic incompatibility (ci). ci involves elevated embryo mortality when infected males mate with uninfected females or females infected with different, incompatible wolbachia strains. the present study focuses on this phenomenon in two drosophila species: d. simulans and d. sechellia. drosophila simulans populations are infected by several wolbachia strains, in ... | 2002 | 12389718 |
| linkage limits the power of natural selection in drosophila. | population genetic theory shows that the efficacy of natural selection is limited by linkage-selection at one site interferes with selection at linked sites. such interference slows adaptation in asexual genomes and may explain the evolutionary advantage of sex. here, we test for two signatures of constraint caused by linkage in a sexual genome, by using sequence data from 255 drosophila melanogaster and drosophila simulans loci. we find that (i) the rate of protein adaptation is reduced in regi ... | 2002 | 12370444 |
| tissue-specificity of 412 retrotransposon expression in drosophila simulans and d. melanogaster. | we analyse the expression of the retrotransposon 412 in the soma, testes, and ovaries in populations of drosophila simulans and d. melanogaster, using rt-pcr and in situ hybridization. we find that expression of 412 is highly variable in the soma, confirming previous findings based on northern blots. no 412rna is detected in the ovaries by either in situ hybridization or rt-pcr, in any population of either species. transcripts are, however, detected in the male germline, which show a very charac ... | 2002 | 12242639 |
| testing models of selection and demography in drosophila simulans. | we analyze patterns of nucleotide variability at 15 x-linked loci and 14 autosomal loci from a north american population of drosophila simulans. we show that there is significantly more linkage disequilibrium on the x chromosome than on chromosome arm 3r and much more linkage disequilibrium on both chromosomes than expected from estimates of recombination rates, mutation rates, and levels of diversity. to explore what types of evolutionary models might explain this observation, we examine a mode ... | 2002 | 12242234 |
| evolution of genome size in drosophila. is the invader's genome being invaded by transposable elements? | genome size varies considerably between species, and transposable elements (tes) are known to play an important role in this variability. however, it is far from clear whether tes are involved in genome size differences between populations within a given species. we show here that in drosophila melanogaster and drosophila simulans the size of the genome varies among populations and is correlated with the te copy number on the chromosome arms. the tes embedded within the heterochromatin do not se ... | 2002 | 12082134 |
| spatially explicit models of turelli-hoffmann wolbachia invasive wave fronts. | this paper examines different mathematical models of insect dispersal and infection spread and compares these with field data. reaction-diffusion and integro-difference equation models are used to model the spatio-temporal spread of wolbachia in drosophila simulans populations. the models include cytoplasmic incompatibility between infected females and uninfected males that creates a threshold density, similar to an allee effect, preventing increase from low incidence of infection in the host po ... | 2002 | 12051989 |
| molecular evolution of the est-6 gene in drosophila melanogaster: contrasting patterns of dna variability in adjacent functional regions. | we have investigated nucleotide polymorphism at the esterase 6 gene (est-6) gene, including the complete coding region (1686 bp), as well as the 5'-flanking (1183 bp) and 3'-flanking (193 bp) regions of the gene, in 30 strains of drosophila melanogaster and in one strain of drosophila simulans. the level of silent variation is similar in the coding and in the 3'-flanking region, but smaller in the 5'-flanking region. strong linkage disequilibrium occurs within each region; and also, although les ... | 2002 | 12034506 |
| [dna from drosophila melanogaster region 61c7/c8 has high evolution rate]. | the results of a comparative study of cloned dna fragments of drosophila simulans, d. mauritiana, d. teissieri, and d. erecta are presented. the fragments were amplified in pcr with primers specified to the region of d. melanogaster interband 61c7/c8. the uniqueness of all cloned fragments in the genomes of these species was confirmed. a comparative analysis of nucleotide sequences revealed that the rate of evolution of dna from d. melanogaster interband 61c7/c8 is close to the rate of neutral e ... | 2002 | 12018164 |
| divergence of mitochondrial dna is not corroborated by nuclear dna, morphology, or behavior in drosophila simulans. | we ask whether the observed mitochondrial dna (mtdna) population subdivision of drosophila simulans is indicative of organismal structure or of specific processes acting on the mitochondrial genome. factors either intrinsic or extrinsic to the host genome may influence the evolutionary dynamics of mtdna. potential intrinsic factors include adaptation of the mitochondrial genome and of nucleomitochondrial gene complexes specific to the local environment. an extrinsic force that has been shown to ... | 2002 | 11989683 |
| an introgression approach to mapping differences in mating success and sperm competitive ability in drosophila simulans and d. sechellia. | the progeny of drosophila females doubly-mated to males from the same and a closely related species are mostly sired by conspecific males. we examined the genetic basis for conspecific mating preference and sperm precedence by using 186 drosophila lines in which random chromosomal fragments of d. sechellia were introgressed into d. simulans. sperm competition was measured for each of these lines by crossing ebony d. simulans female with ebony d. simulans males followed by wild-type males from th ... | 2002 | 11974604 |
| molecular evolutionary analysis of a histone gene repeating unit from drosophila simulans. | a repeating unit of the histone gene cluster from drosophila simulans containing the h1, h2a, h2b and h4 genes (the h3 gene region has already been analyzed) was cloned and analyzed. a nucleotide sequence of about 4.6 kbp was determined to study the nucleotide divergence and molecular evolution of the histone gene cluster. comparison of the structure and nucleotide sequence with those of drosophila melanogaster showed that the four histone genes were located at identical positions and in the sam ... | 2001 | 11922104 |
| dynamics of double and single wolbachia infections in drosophila simulans from new caledonia. | the bacterial symbiont wolbachia can cause cytoplasmic incompatibility in drosophila simulans flies: if an infected male mates with an uninfected female, or a female with a different strain of wolbachia, there can be a dramatic reduction in the number of viable eggs produced. here we explore the dynamics associated with double and single wolbachia infections in new caledonia. doubly infected females were compatible with all males in the population, explaining the high proportion of doubly infect ... | 2002 | 11920119 |
| wolbachia density and virulence attenuation after transfer into a novel host. | the factors that control replication rate of the intracellular bacterium wolbachia pipientis in its insect hosts are unknown and difficult to explore, given the complex interaction of symbiont and host genotypes. using a strain of wolbachia that is known to over-replicate and shorten the lifespan of its drosophila melanogaster host, we have tracked the evolution of replication control in both somatic and reproductive tissues in a novel host/wolbachia association. after transinfection (the transf ... | 2002 | 11880639 |
| testing the neutral theory of molecular evolution with genomic data from drosophila. | although positive selection has been detected in many genes, its overall contribution to protein evolution is debatable. if the bulk of molecular evolution is neutral, then the ratio of amino-acid (a) to synonymous (s) polymorphism should, on average, equal that of divergence. a comparison of the a/s ratio of polymorphism in drosophila melanogaster with that of divergence from drosophila simulans shows that the a/s ratio of divergence is twice as high---a difference that is often attributed to p ... | 2002 | 11875569 |
| adaptive protein evolution in drosophila. | for over 30 years a central question in molecular evolution has been whether natural selection plays a substantial role in evolution at the dna sequence level. evidence has accumulated over the last decade that adaptive evolution does occur at the protein level, but it has remained unclear how prevalent adaptive evolution is. here we present a simple method by which the number of adaptive substitutions can be estimated and apply it to data from drosophila simulans and d. yakuba. we estimate that ... | 2002 | 11875568 |
| characterization of wolbachia host cell range via the in vitro establishment of infections. | maternally transmitted bacteria of the genus wolbachia are obligate, intracellular symbionts that are frequently found in insects and cause a diverse array of reproductive manipulations, including cytoplasmic incompatibility, male killing, parthenogenesis, and feminization. despite the existence of a broad range of scientific interest, many aspects of wolbachia research have been limited to laboratories with insect-rearing facilities. the inability to culture these bacteria outside of the invert ... | 2002 | 11823204 |
| recurrent evolution of dna-binding motifs in the drosophila centromeric histone. | all eukaryotes contain centromere-specific histone h3 variants (cenh3s), which replace h3 in centromeric chromatin. we have previously documented the adaptive evolution of the drosophila cenh3 (cid) in comparisons of drosophila melanogaster and drosophila simulans, a divergence of approximately 2.5 million years. we have proposed that rapidly changing centromeric dna may be driving cenh3's altered dna-binding specificity. here, we compare cid sequences from a phylogenetically broader group of dr ... | 2002 | 11805302 |
| the distribution and proliferation of the intracellular bacteria wolbachia during spermatogenesis in drosophila. | wolbachia is a cytoplasmically inherited alpha-proteobacterium found in a wide range of host arthropod and nematode taxa. wolbachia infection in drosophila is closely associated with the expression of a unique form of post-fertilization lethality termed cytoplasmic incompatibility (ci). this form of incompatibility is only expressed by infected males suggesting that wolbachia exerts its effect during spermatogenesis. the growth and distribution of wolbachia throughout sperm development in indivi ... | 2002 | 11804774 |
| protein variation in drosophila simulans, and comparison of genes from centromeric versus noncentromeric regions of chromosome 3. | 2002 | 11801748 | |
| variable modes of inheritance of morphometrical traits in hybrids between drosophila melanogaster and drosophila simulans. | we investigated body-size inheritance in interspecific sterile hybrids by crossing a drosophila simulans strain with 13 strains of drosophila melanogaster, which were of various origins and chosen for their broad range of genetic variation. a highly significant parent-offspring correlation was observed, showing that the d. melanogaster genes for size are still expressed in a hybrid background. superimposed on to this additive inheritance, the size of hybrids was always less than the mid-parent v ... | 2002 | 11798427 |
| wolbachia-mediated sperm modification is dependent on the host genotype in drosophila. | estimates of wolbachia density in the eggs, testes and whole flies of drosophilid hosts have been unable to predict the lack of cytoplasmic incompatibility (ci) expression in so-called mod(-) variants. consequently, the working hypothesis has been that ci expression, although related to wolbachia density, is also governed by unknown factors that are influenced by both host and bacterial genomes. here, we compare the behaviour of the mod(-) over-replicating wolbachia popcorn strain in its native ... | 2001 | 11749711 |
| the effect of thermal stress on the mating behavior of three drosophila species. | selection may act on the weakest link in fitness to change how a species adapts to an environmental stress. for many species, this limitation may be reproduction. after adult drosophila melanogaster, drosophila simulans, and drosophila mojavensis males were exposed to varying levels of thermal stress well below those that endanger life, courtship and mating frequency declined. the regression coefficients of both courtship and mating success did not differ significantly between d. melanogaster an ... | 2006 | 11731970 |
| sex-ratio segregation distortion associated with reproductive isolation in drosophila. | sex-ratio distortion is the most common form of non-mendelian segregation observed in natural populations. it may occur even more frequently than direct observations suggest, because the dysgenic population consequences of a biased sex ratio are expected to result in the rapid evolution of suppressors, resulting in suppressed or "cryptic" segregation distortion. here we report evidence for cryptic sex-ratio distortion that was discovered by introgressing segments of the genome of drosophila maur ... | 2001 | 11687638 |
| variations of male cuticular hydrocarbons with geoclimatic variables: an adaptative mechanism in drosophila melanogaster? | 7-tricosene (7t) and 7-pentacosene (7p) are the major components of cuticular hydrocarbons in drosophila simulans and d. melanogaster males. a chemical study of 16 isofemale lines of d. melanogaster sampled at the first and eighth generations in laboratory conditions showed the stability of chromatographical profiles. then a large scale study of male 7t/7p polymorphism was performed with 85 populations of d. melanogaster and 29 of d. simulans collected all over the world. there were significant ... | 2000 | 11678502 |
| patterns of dna sequence variation suggest the recent action of positive selection in the janus-ocnus region of drosophila simulans. | levels of nucleotide polymorphism in three paralogous drosophila simulans genes, janusa (jana), janusb (janb), and ocnus (ocn), were surveyed by dna sequencing. the three genes lie in tandem within a 2.5-kb region of chromosome arm 3r. in a sample of eight alleles from a worldwide distribution we found a significant departure from neutrality by several statistical tests. the most striking feature of this sample was that in a 1.7-kb region containing the jana and janb genes, 30 out of 31 segregat ... | 2001 | 11606541 |
| drosophila euchromatic ltr retrotransposons are much younger than the host species in which they reside. | the recent release of the complete euchromatic genome sequence of drosophila melanogaster offers a unique opportunity to explore the evolutionary history of transposable elements (tes) within the genome of a higher eukaryote. in this report, we describe the annotation and phylogenetic comparison of 178 full-length long terminal repeat (ltr) retrotransposons from the sequenced component of the d. melanogaster genome. we report the characterization of 17 ltr retrotransposon families described prev ... | 0 | 11544196 |
| dynamics of r1 and r2 elements in the rdna locus of drosophila simulans. | the mobile elements r1 and r2 insert specifically into the rrna gene locus (rdna locus) of arthropods, a locus known to undergo concerted evolution, the recombinational processes that preserve the sequence homogeneity of all repeats. to monitor how rapidly individual r1 and r2 insertions are turned over in the rdna locus by these processes, we have taken advantage of the many 5' truncation variants that are generated during the target-primed reverse transcription mechanism used by these non-ltr ... | 2001 | 11514447 |
| circadian rhythms of female mating activity governed by clock genes in drosophila. | the physiological and behavioral activities of many animals are restricted to specific times of the day. the daily fluctuation in the mating activity of some insects is controlled by an endogenous clock, but the genetic mechanism that controls it remains unknown. here we demonstrate that wild-type drosophila melanogaster display a robust circadian rhythm in the mating activity, and that these rhythms are abolished in period- or timeless-null mutant flies (per(01) and tim(01)). circadian rhythms ... | 2001 | 11470898 |
| dna variation at the rp49 gene region of drosophila simulans: evolutionary inferences from an unusual haplotype structure. | an approximately 1.3-kb region including the rp49 gene plus its 5' and 3' flanking regions was sequenced in 24 lines of drosophila simulans (10 from spain and 14 from mozambique). fifty-four nucleotide and 8 length polymorphisms were detected. all nucleotide polymorphisms were silent: 52 in noncoding regions and 2 at synonymous sites in the coding region. estimated silent nucleotide diversity was similar in both populations (pi = 0.016, for the total sample). nucleotide variation revealed an unu ... | 2001 | 11454763 |
| the sibling species drosophila melanogaster and drosophila simulans differ in the expression profile of glutathione s-transferases. | two major forms of glutathione s-transferase are known in drosophila melanogaster: gst d and gst 2. in the present paper we report the existence of a third major form of glutathione s-transferase in drosophila simulans. induction with phenobarbital revealed a different regulation of gst between these species. despite the fact that these two species are closely related, there was a difference in the expression profile of the enzyme implicated in the detoxification system, suggesting variations in ... | 2001 | 11435138 |
| the frequency distribution of nucleotide variation in drosophila simulans. | patterns of codon bias in drosophila suggest that silent mutations can be classified into two types: unpreferred (slightly deleterious) and preferred (slightly beneficial). results of previous analyses of polymorphism and divergence in drosophila simulans were interpreted as supporting a mutation-selection-drift model in which slightly deleterious, silent mutants make significantly greater contributions to polymorphism than to divergence. frequencies of unpreferred polymorphisms were inferred to ... | 2001 | 11420372 |
| evolutionary est analysis identifies rapidly evolving male reproductive proteins in drosophila. | sequence comparisons of genomes or expressed sequence tags (ests) from related organisms provide insight into functional conservation and diversification. we compare the sequences of ests from the male accessory gland of drosophila simulans to their orthologs in its close relative drosophila melanogaster, and demonstrate rapid divergence of many of these reproductive genes. nineteen ( approximately 11%) of 176 independent genes identified in the est screen contain protein-coding regions with an ... | 2001 | 11404480 |