Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| wolbachia-induced delay of paternal chromatin condensation does not prevent maternal chromosomes from entering anaphase in incompatible crosses of drosophila simulans. | the behavior of parental chromosomes during the first mitosis of drosophila simulans zygotes obtained from unidirectional incompatible crosses is described and it is demonstrated that the condensation of parental chromatin complements was asynchronous. the timing of paternal chromatin condensation appeared to be delayed in these embryos, so that condensed maternal chromosomes and entangled prophase-like paternal fibers congressed in the equatorial plane of the first metaphase spindle. at anaphas ... | 1997 | 9044057 |
| genetics of sexual isolation in male hybrids of drosophila simulans and d. mauritiana. | sexual isolation between the sibling species d. simulans and d. mauritiana is due largely to the rejection of d. simulans males by d. mauritiana females. genetic analysis shows that genes on the x and third chromosomes contribute to the differences between males causing sexual isolation, while the y chromosome, second chromosome and cytoplasm have no effect. these chromosome effects differ from those observed in a previous analysis of sexual isolation in hybrid females, implying that different g ... | 1996 | 9062078 |
| an introgression analysis of quantitative trait loci that contribute to a morphological difference between drosophila simulans and d. mauritiana. | drosophila simulans and d. mauritiana differ markedly in morphology of the posterior lobe, a male-specific genitalic structure. both size and shape of the lobe can be quantified by a morphometric variable, pcl, derived from principal components and fourier analyses. the genetic architecture of the species difference in pcl was investigated previously by composite interval mapping, which revealed largely additive inheritance, with a minimum of eight quantitative trait loci (qtl) affecting the tra ... | 1997 | 9071588 |
| genetic basis of sperm and testis length differences and epistatic effect on hybrid inviability and sperm motility between drosophila simulans and d. sechellia. | results are reported from a genetic study of hybrid inviability and three 'fertilization traits' (sperm motility and length, and testis size) that affect hybrid sterility between the sibling species drosophila simulans and d. sechellia. the main findings are as follows. (i) for sperm length there was a dominant effect of the d. simulans genome over that of d. sechellia, and the y chromosome of d. sechellia in the background of d. simulans reduced the sperm length. (ii) in contrast, testis length ... | 1997 | 9134705 |
| nucleotide sequence divergence in the a+t-rich region of mitochondrial dna in drosophila simulans and drosophila mauritiana. | we have determined the nucleotide sequences of two regions within the a+t-rich region of mitochondrial dna (mtdna) in the siiii type of drosophila simulans and the mai type of d. mauritiana. the sequences of the two regions in siiii and mai are almost identical. the sequences include elements corresponding to the type i and type ii repeats elements and the t-stretches as reported in d. melanogaster; an approximately 340-bp region (a region) adjacent to the trna(ile) gene includes a part of the t ... | 1997 | 9254919 |
| chromosomal distribution of the 412 retrotransposon in natural populations of drosophila simulans. | the insertion site localization of the 412 retrotransposable element was analysed by in situ hybridization to the polytene chromosomes of 57 individual genomes from 25 natural populations of drosophila simulans. the 412 insertion sites along the chromosomes show a tendency to aggregate in the distal and proximal ends of the 2r arm, and in several local regions along the 3r arm. the distribution of the 412 insertion sites, weighted by dna content, along the chromosome arms reveals an overall tend ... | 1997 | 9279009 |
| infection of the gonads of the simes strain of drosophila simulans by the hereditary reovirus dsv. | the s character of drosophila simulans simes-st strain undergoes a non-mendelian transmission. it has been postulated that a virus, drosophila s virus (dsv), could be the causative agent. electron microscopy analysis of gonads of flies showing a strong s phenotype revealed the presence of virus in or near the germ cells. the s character transmission rate is greater in females than that in males. similarly, the level of infection by dsv is higher in ovaries than that in testes. flies treated at a ... | 1997 | 9281403 |
| the sex-ratio trait in drosophila simulans: genetic analysis of distortion and suppression. | the sex-ratio trait described in several drosophila species is a type of naturally occurring x-linked meiotic drive that causes males bearing a sex-ratio x chromosome to produce progenies with a large excess of females. we have previously reported the occurrence of sex-ratio x chromosomes in drosophila simulans. in this species, because of the co-occurrence of drive suppressors, the natural populations and the derived laboratory strains show an equal sex-ratio even when sex-ratio x chromosomes a ... | 1997 | 9335600 |
| nonrandom partition of mitochondria in heteroplasmic drosophila. | in order to understand the status of heteroplasmy and its evolution within the drosophila melanogaster subgroup, cytoplasm microinjections between eggs were performed involving three lineages of drosophila simulans, carrying the sii, siii or siiii mtdna type, respectively, and two strains of drosophila mauritiana carrying the mai or maii mtdna type. progeny of eggs from all combinations of injection were analysed. the maii or sii molecules, when provided by the donor, were never detected in the ... | 1997 | 9418268 |
| codon bias evolution in drosophila. population genetics of mutation-selection drift. | although non-random patterns of synonymous codon usage are a prominent feature in the genomes of many organisms, the relatives roles of mutational biases and natural selection in maintaining codon bias remain a contentious issue. in some species, patterns of codon bias and empirical findings on the biology of translation suggest 'major codon preference', a balance among mutation pressure, genetic drift, and weak selection in favor of translationally superior codons. population genetics theory ma ... | 1997 | 9461401 |
| genetics of hybridization between drosophila simulans females and d. melanogaster males. | drosophila simulans and d. melanogaster are sibling cosmopolitan species with imperfect ethological isolation. hybridization is easy between d. melanogaster females and d. simulans males, but the reciprocal cross has been traditionally considered as very scarce and little is known about the environmental and genetic factors that affect it. we used classical genetic analyses to determine the influence of each major chromosome on the breakdown of sexual isolation between females of d. simulans and ... | 1998 | 9474773 |
| inheritance mode of drosophila simulans female mating propensity with d. melanogaster males. | the genetic factors involved in the sexual isolation between drosophila simulans females and d. melanogaster males are hardly known. we present a study of female mating propensity of d. simulans from different geographic origins with d. melanogaster males. our results reveal the existence of genetic variability in d. simulans for this trait. female discrimination is dominant against high female interspecific mating, which differs from that detected in other drosophila species crosses. | 2006 | 9487683 |
| conservation of locus-specific microsatellite variability across species: a comparison of two drosophila sibling species, d. melanogaster and d. simulans. | fifteen microsatellite loci were studied in drosophila melanogaster and drosophila simulans, two closely related sibling species which split 2-3.5 mya. within-species variances in repeat number were found to differ up to 1,000-fold among individual microsatellite loci. a significant correlation of log variances between both species indicated a locus-specific mutation rate of microsatellites. hence, locus-specific effects are apparently among the major forces influencing microsatellite variation ... | 1998 | 9491614 |
| overcoming cytoplasmic incompatibility in drosophila. | the endocellular microbe wolbachia pipientis infects a wide variety of invertebrate species, in which its presence is closely linked to a form of reproductive failure termed cytoplasmic incompatibility (ci). ci renders infected males unable to father offspring when mated to uninfected females. because ci can dramatically affect fitness in natural populations, mechanisms that abate ci can have equally large impacts on fitness. we have discovered that repeated copulation by wolbachia-infected male ... | 1998 | 9523438 |
| isolation of protease-free alcohol dehydrogenase (adh) from drosophila simulans and several homozygous and heterozygous drosophila melanogaster variants. | the enzyme alcohol dehydrogenase (adh) from several naturally occurring adh variants of drosophila melanogaster and drosophila simulans was isolated. affinity chromatography with the ligand cibacron blue and elution with nad+ showed similar behavior for d. melanogaster adh-ff, adh-71k, and d. simulans adh. introduction of a second cibacron blue affinity chromatography step, with gradient elution with nad+, resulted in pure and stable enzymes. d. melanogaster adh-ss cannot be eluted from the affi ... | 1998 | 9562904 |
| accumulation of transposable elements in the heterochromatin and on the y chromosome of drosophila simulans and drosophila melanogaster. | the elements of the transposon families g, copia, mdg 1, 412, and gypsy that are located in the heterochromatin and on the y chromosome have been identified by the southern blotting technique in drosophila simulans and d. melanogaster populations. within species, the abundance of such elements differs between transposon families. between species, the abundance in the heterochromatin and on the y chromosome of the elements of the same family can differ greatly suggesting that differences within a ... | 1998 | 9608048 |
| rate variation of dna sequence evolution in the drosophila lineages. | rate constancy of dna sequence evolution was examined for three species of drosophila, using two samples: the published sequences of eight genes from regions of the normal recombination rates and new data of the four as-c (ac, sc, l'sc and ase) and ci genes. the as-c and ci genes were chosen because these genes are located in the regions of very reduced recombination in drosophila melanogaster and their locations remain unchanged throughout the entire lineages involved, yielding less effect of a ... | 1998 | 9611206 |
| nucleotide variation in the triosephosphate isomerase (tpi) locus of drosophila melanogaster and drosophila simulans. | dna sequence variation in a 1.1-kb region including the coding portion of the tpi locus was examined in 25 homozygous third-chromosome lines of drosophila melanogaster, nine lines of drosophila simulans, and one line of drosophila yakuba. our data show that the widespread allozyme polymorphism observed in cosmopolitan d. melanogaster is due to a glutamic acid substitution occurring in a phylogenetically conserved lysine that has been identified as part of the "hinged-lid" active site of the enzy ... | 1998 | 9615457 |
| sex-related genes, directional sexual selection, and speciation. | reproductive isolation and speciation can result from the establishment of either premating or postmating barriers that restrict gene flow between populations. recent studies of speciation have been dominated by a molecular approach to dissect the genetic basis of hybrid male sterility, a specific form of postmating reproductive isolation. however, relatively little attention has been paid to the evolution of genes involved in premating isolation and genes generally involved in other sex-related ... | 1998 | 9656489 |
| a temperature cline in copy number for 412 but not roo/b104 retrotransposons in populations of drosophila simulans. | the copy number of the retrotransposable element 412 of drosophila simulans from populations collected worldwide shows a negative correlation with minimum temperature. no association was detected for the roo/b104 element. the possibility that selective pressures might regulate the 412 copy number in these natural populations is supported by detection of selection against the detrimental effects of 412 insertions (estimated by the proportion of insertions on the x chromosome in comparison with th ... | 1998 | 9699309 |
| hidden effects of x chromosome introgressions on spermatogenesis in drosophila simulans x d. mauritiana hybrids unveiled by interactions among minor genetic factors. | one of the most frequent outcomes of interspecific hybridizations in drosophila is hybrid male sterility. genetic dissection of this reproductive barrier has revealed that the number of responsible factors is very high and that these factors are frequently engaged in complex epistatic interactions. traditionally, research strategies have been based on contrasting introgressions of chromosome segments that produce male sterility with those that allow fertility. few studies have investigated the p ... | 1998 | 9755205 |
| genetic variation and differentiation at microsatellite loci in drosophila simulans. evidence for founder effects in new world populations. | drosophila simulans isofemale lines from africa, south america, and two locations in north america were surveyed for variation at 16 microsatellite loci on the x, second, and third chromosomes, and 18 microsatellites, which are unmapped. d. simulans is thought to have colonized new world habitats only relatively recently (within the last few hundred years). consistent with a founder effect occurring as colonizers moved into these new world habitats, we find less microsatellite variability in nor ... | 1998 | 9755208 |
| characterization of a hypermutable strain of drosophila simulans. | a hypermutable strain of drosophila simulans that originated from a single spontaneous mutant male was characterized. seven different mutations were isolated from roughly 100 generations of offspring. the genetic analysis of the viable mutants showed two mutations on the x chromosome, one in the lozenge locus and the other in the ruby gene. the autosomic mutations characterized were a dpp-heldout-like, a blistered-like and a homoeotic dominant mutant with an antenna-to-leg transformation and ect ... | 1998 | 9849620 |
| duplication of the rdl gaba receptor subunit gene in an insecticide-resistant aphid, myzus persicae. | resistance to cyclodiene insecticides is associated with replacements of a single amino acid (alanine 302) in a gamma-aminobutyric acid (gaba) receptor subunit encoded by the single-copy gene resistance to dieldrin (rdl). alanine 302 is predicted to reside within the second membrane-spanning region of the rdl receptor, a region that is thought to line the integral chloride ion channel pore. in all cyclodiene-resistant insects studied to date, this same alanine residue is replaced either by a ser ... | 1998 | 9862468 |
| distribution of the retrotransposable element 412 in drosophila species. | copy numbers of sequences homologous to the drosophila melanogaster retrotransposable element 412, their distribution between the chromosome arms and the chromocenter, and whether they contain full-size copies were analyzed for 55 species of the drosophila genus. element 412 insertion sites were detected on the chromosome arms of d. melanogaster, drosophila simulans, and a few species of the obscura group, but the chromocenter was labeled in almost all species. the presence of element 412 sequen ... | 1998 | 9866195 |
| microsatellite variation in drosophila melanogaster and drosophila simulans: a reciprocal test of the ascertainment bias hypothesis. | interspecific comparisons of microsatellite loci have repeatedly shown that the loci are longer and more variable in the species from which they are derived (the focal species) than are homologous loci in other (nonfocal) species. there is debate as to whether this is due to directional evolution or to an ascertainment bias during the cloning and locus selection processes. this study tests these hypotheses by performing a reciprocal study. eighteen perfect dinucleotide microsatellite loci identi ... | 1998 | 9866198 |
| inferring the fitness effects of dna mutations from polymorphism and divergence data: statistical power to detect directional selection under stationarity and free recombination. | the fitness effects of classes of dna mutations can be inferred from patterns of nucleotide variation. a number of studies have attributed differences in levels of polymorphism and divergence between silent and replacement mutations to the action of natural selection. here, i investigate the statistical power to detect directional selection through contrasts of dna variation among functional categories of mutations. a variety of statistical approaches are applied to dna data simulated under sawy ... | 1999 | 9872962 |
| survey of malathion resistance and avermectin susceptibility in field populations of drosophila melanogaster (diptera: drosophilidae) and d. simulans. | populations of drosophila melanogaster (meigen) and drosophila simulans (sturtevant) from various geographic locations in north america and elsewhere were sampled to assess the distribution of malathion resistance and avermectin tolerance. comparisons are made to previous reports of a differential response to malathion selection in these species. results indicate that for malathion, resistance is widespread in d. simulans but varies considerably in d. melanogaster. for avermectins, although the ... | 1998 | 9887681 |
| cross-order transfer of wolbachia from muscidifurax uniraptor (hymenoptera: pteromalidae) to drosophila simulans (diptera: drosophilidae). | bacteria of the genus wolbachia are widespread in arthropods and can induce different effects on the host such as cytoplasmic incompatibility (ci), thelytoky (t) or feminization (f). in some wolbachia-infected hosts, no effect (n) has been found. successful transfer of wolbachia by microinjection from one host to an uninfected one has been established with ci, f, n-wolbachia but not with t-wolbachia. in this paper a transfer experiment of t-wolbachia from the parasitoid muscidifurax uniraptor to ... | 1999 | 10098265 |
| horizontal transfer of wolbachia between phylogenetically distant insect species by a naturally occurring mechanism. | wolbachia is a genus of alpha-proteobacteria found in obligate intracellular association with a wide variety of arthropods, including an estimated 10-20% of all insect species [1]. wolbachia represents one of a number of recently identified 'reproductive parasites' [2] which manipulate the reproduction of their hosts in ways that enhance their own transmission [3] [4] [5] [6] [7] [8] [9]. the influence of wolbachia infection on the dynamics of host populations has focused considerable interest o ... | 1999 | 10209097 |
| molecular identification of the active ninja retrotransposon and the inactive aurora element in drosophila simulans and d. melanogaster. | how transposable elements evolve is a key facet in understanding of spontaneous mutation and genomic rearrangements in various organisms. one of the best ways to approach this question is to study a newly evolved transposable element whose presence is restricted to a specific population or strain. the retrotransposons ninja and aurora may provide insights into the process of their evolution, because of their contrasting characteristics, even though they show high sequence identity. the ninja ret ... | 1998 | 10333568 |
| polymorphism in structure of the retrotransposable element 412 in drosophila simulans and d. melanogaster populations. | the structure of the 412 retrotransposable element was investigated in various natural populations of d. melanogaster and d. simulans by a restriction enzyme analysis. we show that although the canonical structure of the 412 element was the same in both species, a high structural polymorphism existed with various rearranged elements. a 412 family was thus composed of heterogeneous copies of different sizes, with a large proportion of full-size copies. d. simulans had more rearranged copies than ... | 1999 | 10352229 |
| nucleotide variation at the runt locus in drosophila melanogaster and drosophila simulans. | intra- and interspecific nucleotide variation for the major developmental gene runt in drosophila was studied in d. melanogaster and d. simulans. the 1.5-kb protein-coding region and the 0.4-kb intron of the runt gene were sequenced for 11 alleles in each species. the d. melanogaster alleles originated from east africa. estimated parameters of intraspecific variation in d. melanogaster (exons: theta = 0.018, pi = 0.018; intron: theta = 0.014, pi = 0.014) and d. simulans (exons: theta = 0.007, pi ... | 1999 | 10368951 |
| a stable triple wolbachia infection in drosophila with nearly additive incompatibility effects. | drosophila simulans strains infected with three different wolbachia strains were generated by experimental injection of a third symbiont into a naturally double-infected strain. this transfer led to a substantial increase in total wolbachia density in the host strain. each of the three symbionts was stably transmitted in the presence of the other two. triple-infected males were incompatible with double-infected females. no evidence was obtained for interference between modification effects of th ... | 1999 | 10383683 |
| centromeres from telomeres? the centromeric region of the y chromosome of drosophila melanogaster contains a tandem array of telomeric het-a- and tart-related sequences. | cytological and cytogenetic studies have previously defined the region needed for centromeric function in the y chromosome of drosophila melanogaster. we have identified a yac clone that originated from this region. molecular analysis of the yac and genomic dnas has allowed the description of a satellite dna made of telomeric het-a- and tart-derived sequences and the construction of a long-range physical map of the heterochromatic region h18. sequences within the yac clone are conserved in the c ... | 1999 | 10454639 |
| population structure among african and derived populations of drosophila simulans: evidence for ancient subdivision and recent admixture. | previous studies based on allozyme variation have found little evidence for genetic differentiation in drosophila simulans. on the basis of dna sequence variation at two nuclear loci in four african populations of d. simulans, we show that there is significant structure to d. simulans populations within africa. variation at one of the loci, vermilion, appears to be neutral and supports an eastern african origin for european and american populations. samples from the west indies, europe, and nort ... | 1999 | 10471714 |
| wake up of transposable elements following drosophila simulans worldwide colonization. | transposable elements (tes) make up around 10%-15% of the drosophila melanogaster genome, but its sibling species drosophila simulans carries only one third as many such repeat sequences. we do not, however, have an overall view of copy numbers of the various classes of tes (long terminal repeat [ltr] retrotransposons, non-ltr retrotransposons, and transposons) in genomes of natural populations of both species. we analyzed 34 elements in individuals from various natural populations of these spec ... | 1999 | 10486980 |
| the genetics and evolution of the mariner transposable element in drosophila simulans: worldwide distribution and experimental population dynamics. | we have studied both the frequency and biogeographical distribution of the transposable dna element mariner in natural populations of drosophila simulans and the short-term evolutionary characteristics of mariner in experimental populations. the mariner element has been identified in natural populations of d. simulans from africa, europe, the middle east, japan, australia, several pacific islands, north america, and south america. only four lines out of 296 were devoid of active mariner elements ... | 1999 | 10568259 |
| a quantitative genetic analysis of male sexual traits distinguishing the sibling species drosophila simulans and d. sechellia. | a quantitative trait locus (qtl) genetic analysis of morphological and reproductive traits distinguishing the sibling species drosophila simulans and d. sechellia was carried out in a backcross design, using 38 markers with an average spacing of 8.4 cm. the direction of qtl effects for the size of the posterior lobe was consistent across the identified qtl, indicating directional selection for this trait. directional selection also appears to have acted on testis length, indicating that sexual s ... | 1999 | 10581276 |
| microsatellite markers for interspecific mapping of drosophila simulans and d. sechellia. | 1999 | 10620238 | |
| sex-ratio meiotic drive in drosophila simulans is related to equational nondisjunction of the y chromosome. | the sex-ratio trait, an example of naturally occurring x-linked meiotic drive, has been reported in a dozen drosophila species. males carrying a sex-ratio x chromosome produce an excess of female offspring caused by a deficiency of y-bearing sperm. in drosophila simulans, such males produce approximately 70-90% female offspring, and 15-30% of the male offspring are sterile. here, we investigate the cytological basis of the drive in this species. we show that the sex-ratio trait is associated wit ... | 2000 | 10628983 |
| genetic architecture of a morphological shape difference between two drosophila species. | the size and shape of the posterior lobe of the male genital arch differs dramatically between drosophila simulans and d. mauritiana. this difference can be quantified with a morphometric descriptor (pc1) based on elliptical fourier and principal components analyses. the genetic basis of the interspecific difference in pc1 was investigated by the application of quantitative trait locus (qtl) mapping procedures to segregating backcross populations. the parental difference (35 environmental standa ... | 2000 | 10628989 |
| [analysis of differences in the structure of ribosomal dna from two sibling species: drosophila melanogaster and drosophila simulans]. | southern-blot hybridization studies have revealed structural differences within the ribosomal dna clusters of two sibling species, drosophila melanogaster and drosophila simulans. the approach used was shown to be suitable for taxonomic identification of the species examined. | 1999 | 10687091 |
| genetic analysis of speciation by means of introgression into drosophila melanogaster. | in the last decade, the genetic basis of reproductive isolation has been shown to be surprisingly polygenic, and yet even the most efficient system currently in use could lend itself to molecular analysis only in highly selected cases. by extending the recent discovery of fertility rescue between drosophila melanogaster and drosophila simulans, we show that this hybridization can permit systematic and precise delineation of the genetic and molecular basis of speciation. in a region of 5% of the ... | 2000 | 10706624 |
| the evolution of an alpha-esterase pseudogene inactivated in the drosophila melanogaster lineage. | previous analyses of the alpha-esterase cluster of drosophila melanogaster revealed 10 active genes and the dmalphae4a-psi pseudogene. here, we reconstruct the evolution of the pseudogene from the sequences of 12 alleles from widely scattered d. melanogaster populations and single alleles from drosophila simulans and drosophila yakuba. all of the dmalphae4a-psi alleles contain numerous inactivating mutations, suggesting that pseudogene alleles are fixed in natural populations. several lines of e ... | 2000 | 10742048 |
| adaptive evolution of relish, a drosophila nf-kappab/ikappab protein. | nf-kappab and ikappab proteins have central roles in regulation of inflammation and innate immunity in mammals. homologues of these proteins also play an important role in regulation of the drosophila immune response. here we present a molecular population genetic analysis of relish, a drosophila nf-kappab/ikappab protein, in drosophila simulans and d. melanogaster. we find strong evidence for adaptive protein evolution in d. simulans, but not in d. melanogaster. the adaptive evolution appears t ... | 2000 | 10757765 |
| the phylogeny of closely related species as revealed by the genealogy of a speciation gene, odysseus. | molecular differentiation between races or closely related species is often incongruent with the reproductive divergence of the taxa of interest. shared ancient polymorphism and/or introgression during secondary contact may be responsible for the incongruence. at loci contributing to speciation, these two complications should be minimized (1, 2); hence, their variation may more faithfully reflect the history of the species' reproductive differentiation. in this study, we analyzed dna polymorphis ... | 2000 | 10779562 |
| offsetting effects of wolbachia infection and heat shock on sperm production in drosophila simulans: analyses of fecundity, fertility and accessory gland proteins. | infection in drosophila simulans with the endocellular symbiont wolbachia pipientis results in egg lethality caused by failure to properly initiate diploid development (cytoplasmic incompatibility, ci). the relationship between wolbachia infection and reproductive factors influencing male fitness has not been well examined. here we compare infected and uninfected strains of d. simulans for (1) sperm production, (2) male fertility, and (3) the transfer and processing of two accessory gland protei ... | 2000 | 10790392 |
| reduced x-linked nucleotide polymorphism in drosophila simulans. | population genetic theory predicts that selectively driven changes of allele frequency for both beneficial and deleterious mutants reduce polymorphism at tightly linked sites. all else being equal, these reductions in polymorphism are expected to be greater when recombination rates are lower. therefore, the empirical observation of a positive correlation between recombination rates and amounts of dna polymorphism across the drosophila melanogaster genome can be explained by two very different ty ... | 2000 | 10823947 |
| location of shfr, a new gene that rescues hybrid female viability in crosses between drosophila simulans females and d. melanogaster males. | as a rule, progeny of crosses between drosophila simulans females and d. melanogaster males are formed by sterile males, because females die as embryos. however, populations of these species have been found that produce a certain frequency of viable hybrid females. we have found that 94% of the females of a d. simulans population from tel aviv gave hybrid progenies with both sexes. the segregation of phenotypes with different rescue success adjusts to the action of a single, dominant, zygotic-ac ... | 2000 | 10886378 |
| structural and genetic studies of the proliferation disrupter genes of drosophila simulans and d. melanogaster. | to examine whether structural and functional differences exist in the proliferation disrupter (prod) genes between drosophila simulans and d. melanogaster, we analyzed and compared both genes. the exon-intron structure of the prod genes was found to be the same--three exons were interrupted by two introns, although a previous report suggested that only one intron existed in d. melanogaster. the prod genes of d. simulans and d. melanogaster both turn out to encode 346 amino acids, not 301 as prev ... | 1999 | 10897796 |
| comparative genomics of mitochondrial dna in drosophila simulans. | the current study compares the nucleotide variation among 22 complete mitochondrial genomes of the three distinct drosophila simulans haplotypes with intron 1 of the alcohol dehydrogenase-related locus. this is the first study to investigate the sequence variation of multiple complete mitochondrial genomes within distinct mitochondrial haplotypes of a single species. patterns of variation suggest distinct forces are influencing the evolution of mitochondrial dna (mtdna) and autosomal dna in d. s ... | 2000 | 10903373 |
| high density of long dinucleotide microsatellites in drosophila subobscura. | we isolated 96 dinucleotide repeats with five or more tandemly repeated units from a subgenomic drosophila subobscura library. the mean repeat unit length of microsatellite clones in d. subobscura is 15, higher than that observed in other drosophila species. population variation was assayed in 32-40 chromosomes from barcelona, spain, using 18 randomly chosen microsatellite loci. positive correlation between measures of variation and perfect repeat length measures (mean size, most common, and lon ... | 2000 | 10908646 |
| transposable elements and genome evolution: the case of drosophila simulans. | drosophila simulans presents a large variation in copy number among various transposable elements (tes) and among natural populations for a given element. some elements such as hms beagle, blood, flea, tirant, coral, prygun, jockey, f, nomade and mariner are absent in most populations, except in one or two which have copies on their chromosome arms. this suggests that some tes are being awakened in d. simulans and are in the process of invading the species while it is colonizing the world. the e ... | 1999 | 10952204 |
| high copy numbers of multiple transposable element families in an australian population of drosophila simulans. | sudden mobilization of transposable elements in drosophila is a well-reported phenomenon but one that usually affects no more than a few elements (one to four). we report here the existence of a d. simulans natural population (canberra) from australia, which had high copy numbers for various transposable elements (transposons, ltr retrotransposons and non-ltr retrotransposons). the impact of transposable elements on the host genome and populations is discussed. | 2000 | 11006639 |
| wolbachia segregation rate in drosophila simulans naturally bi-infected cytoplasmic lineages. | wolbachia are maternally transmitted endocellular bacteria infecting several arthropod species. in order to study wolbachia segregation rate, drosophila simulans females from an indo-pacific population (seychelles) bi-infected by the two wolbachia variants wha and wno were backcrossed to uninfected males in two conditions. in the first case, seychelles males from a stock cured from its wolbachia by tetracycline treatment were used. in the second case, the males came from a naturally uninfected t ... | 2000 | 11012722 |
| nonrandom mating in drosophila melanogaster laboratory populations derived from closely adjacent ecologically contrasting slopes at "evolution canyon". | ecological differentiation of natural populations of drosophila melanogaster, drosophila simulans, and another drosophilid, zaprionus tuberculatus, in "evolution canyon," mount carmel, israel, is well established. the fitness complex of d. melanogaster includes oviposition temperature preferences, tolerance to high temperature, drought stress and starvation, and different longevity patterns. this remarkable differentiation has evolved despite small interslope distances (only 100-400 m), within e ... | 2000 | 11050149 |
| characterization of defects in adult germline development and oogenesis of sterile and rescued female hybrids in crosses between drosophila simulans and drosophila melanogaster. | crosses between drosophila melanogaster and d. simulans normally result in progeny that are either inviable or sterile. recent discovery of strains that rescue these inviability and sterility phenotypes has made it possible to study the developmental basis of reproductive isolation between these two species in greater detail. by producing both rescued and unrescued hybrids and examining the protein product staining patterns of genes known to be involved in early germline development and gametoge ... | 2000 | 11069139 |
| the population genetics of the origin and divergence of the drosophila simulans complex species. | the origins and divergence of drosophila simulans and close relatives d. mauritiana and d. sechellia were examined using the patterns of dna sequence variation found within and between species at 14 different genes. d. sechellia consistently revealed low levels of polymorphism, and genes from d. sechellia have accumulated mutations at a rate that is approximately 50% higher than the same genes from d. simulans. at synonymous sites, d. sechellia has experienced a significant excess of unpreferred ... | 2000 | 11102384 |
| expression of cytoplasmic incompatibility in drosophila simulans and its impact on infection frequencies and distribution of wolbachia pipientis. | the aim of this study is to examine the expression of cytoplasmic incompatibility and investigate the distribution and population frequencies of wolbachia pipientis strains in drosophila simulans. nucleotide sequence data from 16s rdna and a wolbachia surface protein coding sequence and cytoplasmic incompatibility assays identify four distinct wolbachia strains: wha, wri, wma, and wau. the levels of cytoplasmic incompatibility between six lines carrying these strains of bacteria and three contro ... | 2000 | 11108593 |
| nucleotide variation at the yellow gene region is not reduced in drosophila subobscura: a study in relation to chromosomal polymorphism. | in contrast to drosophila melanogaster and drosophila simulans, the yellow (y) gene region of drosophila subobscura is not located in a region with a strong reduction in recombination. in addition, this gene maps very close to the breakpoints of different inversions that segregate as polymorphic in natural populations of d. subobscura. therefore, levels of variation at the y gene region in this species relative to those found in d. melanogaster and d. simulans may be affected not only by the cha ... | 2000 | 11110911 |
| wolbachia neither induces nor suppresses transcripts encoding antimicrobial peptides. | wolbachia are intracellular maternally inherited microorganisms that are associated with reproductive abnormalities such as cytoplasmic incompatibility (ci), feminization and parthenogenesis in the various arthropod species they infect. surveys indicate that these bacteria infect more than 16% of all insect species as well as isopods, mites and nematodes, making wolbachia one of the most ubiquitous parasites yet described. however, nothing is known about the interactions of this bacterium with t ... | 2000 | 11122472 |
| developmental expression of the 412 retrotransposon in natural populations of d. melanogaster and d. simulans. | we analysed the pattern of expression of retrotransposon 412 through developmental stages in various populations of drosophila simulans and d. melanogaster differing in 412 copy number. we found that the 412 expression pattern varied greatly between populations of both species, indicating that such patterns were not entirely species-specific. in d. simulans, total transcripts increased with number of 412 copies in the chromosomes when this number was low, and then decreased for high copy numbers ... | 2000 | 11204969 |
| mechanisms of conspecific sperm precedence in drosophila. | the postmating, prezygotic isolating mechanism known as conspecific sperm precedence (csp) may play an important role in speciation, and understanding the mechanism of csp is important in reconstructing its evolution. when a drosophila simulans female mates with both a d. simulans male and a d. mauritiana male, the vast majority of her progeny are fathered by d. simulans, regardless of the order of mating. the dearth of hybrid progeny does not result from inviability of eggs fertilized by hetero ... | 2000 | 11209779 |
| contrasting patterns of x-linked and autosomal nucleotide variation in drosophila melanogaster and drosophila simulans. | surveys of molecular variation in drosophila melanogaster and drosophila simulans have suggested that diversity outside of africa is a subset of that within africa. it has been argued that reduced levels of diversity in non-african populations reflect a population bottleneck, adaptation to temperate climates, or both. here, i summarize the available single-nucleotide polymorphism data for both species. a simple "out of africa" bottleneck scenario is consistent with geographic patterns for loci o ... | 2001 | 11230529 |
| recombination and the frequency spectrum in drosophila melanogaster and drosophila simulans. | most "tests of neutrality" assess whether particular data sets depart from the predictions of a standard neutral model with no recombination. for drosophila, where nuclear polymorphism data routinely show evidence of genetic exchange, the assumption of no recombination is often unrealistic. in addition, while conservative, this assumption is made at the cost of a great loss in power. perhaps as a result, tests of the frequency spectrum based on zero recombination suggest an adequate fit of droso ... | 2001 | 11230530 |
| cryptic reproductive isolation in the drosophila simulans species complex. | forms of reproductive isolation that act after copulation but before fertilization are potentially important components of speciation, but are studied only infrequently. we examined postmating, prezygotic reproductive isolation in three hybridizations within the drosophila simulans species complex. we allowed females to mate only once, observed and timed all copulations, dissected a subset of the females to track the storage and retention of sperm, examined the number and hatchability of eggs la ... | 2001 | 11263748 |
| two novel pao-like retrotransposons (kamikaze and yamato) from the silkworm species bombyx mori and b. mandarina: common structural features of pao-like elements. | to characterize the structural features common to pao-like retrotransposons, we analyzed two lambda phage clones which contain the pao-like elements from the silkworm species bombyx mori and b. mandarinia, and copies of pao itself and ninja of drosophila simulans, amplified by pcr. we previously identified two randomly amplified polymorphic dnas (rapds), w-kamikaze and w-yamato, from b. mori and b. mandarina, which are part of two novel pao-like retrotransposons, kamikaze and yamato, respectivel ... | 2001 | 11361350 |
| the y chromosomes of drosophila simulans are highly polymorphic for their ability to suppress sex-ratio drive. | the sex-ratio trait, known in several species of drosophila including d. simulans, results from meiotic drive of the x chromosome against the y. males that carry a sex-ratio x chromosome produce strongly female-biased progeny. in d. simulans, drive suppressors have evolved on the y chromosome and on the autosomes. both the frequency of sex-ratio x and the strength of the total drive suppression (y-linked and autosomal) vary widely among geographic populations of this worldwide species. we have i ... | 2001 | 11392391 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| protein variation in drosophila simulans, and comparison of genes from centromeric versus noncentromeric regions of chromosome 3. | 2002 | 11801748 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |