| association of misexpression with sterility in hybrids of drosophila simulansand d. mauritiana. | recent studies have identified genes associated with hybrid sterility and other hybrid dysfunctions, but the consequences of introgressions of these "speciation genes" are often poorly understood. previously, we identified a panel of genes that are underexpressed in sterile male hybrids of drosophila simulans and d. mauritiana relative to pure species. here, we build on this reverse-genetics approach to demonstrate that the underexpression of at least five of these genes in hybrids is associated ... | 2004 | 15486701 |
| identification of a locus under complex positive selection in drosophila simulans by haplotype mapping and composite-likelihood estimation. | the recent action of positive selection is expected to influence patterns of intraspecific dna sequence variation in chromosomal regions linked to the selected locus. these effects include decreased polymorphism, increased linkage disequilibrium, and an increased frequency of derived variants. these effects are all expected to dissipate with distance from the selected locus due to recombination. therefore, in regions of high recombination, it should be possible to localize a target of selection ... | 2004 | 15454542 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| protein variation in drosophila simulans, and comparison of genes from centromeric versus noncentromeric regions of chromosome 3. | | 2002 | 11801748 |
| 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 |
| 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 |
| 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 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 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| microsatellite markers for interspecific mapping of drosophila simulans and d. sechellia. | | 1999 | 10620238 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| transposition rate of the 412 retrotransposable element is independent of copy number in natural populations of drosophila simulans. | the transposition and excision rates of the 412 retrotransposable element were estimated in five populations of drosophila simulans differing in their average 412 copy numbers, which ranged from 2 to 54. the transposition rate was found to equal 1 x 10(-3) to 2 x 10(-3), independently of copy number. no excision was detected. these values eliminate autoregulation as a force maintaining copy number of the 412 element in natural populations of d. simulans. | 1997 | 9029796 |
| conceptual translation of timeless reveals alternative initiating methionines in drosophila. | we have sequenced genomic fragments which encode the n-terminus of the timeless (tim) clock protein in drosophila simulans and d. yakuba. we observe that in these two species, the initiating methionine appears to lie downstream of the one proposed to encode the translational start ind.melanogaster, thereby truncating the n-terminus by 23 amino acids. we then sequenced the corresponding 5'fragment in a number of d. melanogaster individuals from different strains. we observed a polymorphism which ... | 1997 | 9016581 |
| 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 |
| population genetics of silent and replacement variation in drosophila simulans and d. melanogaster: x/autosome differences? | | 1996 | 8952085 |
| somatic activity of the mariner transposable element in natural populations of drosophila simulans. | the characteristics of the mariner transposable element in natural populations of drosophila simulans from different parts of the world were analysed. the somatic excision rate (estimated from a test-cross with a reference strain), the average number of copies (determined by southern blots), and the presence of deleted copies (detected by polymerase chain reaction amplification) were estimated for each population. there was a great variability in the somatic excision rate, measured as the percen ... | 1996 | 8952091 |
| discord between the phylogenies inferred from molecular versus functional data: uneven rates of functional evolution or low levels of gene flow? | according to measures of molecular divergence, the three species of the drosophila simulans clade are closely related to and essentially equidistant from each other. we introgressed 10% of the d. sechellia x chromosome into a pure d. simulans genetic background and found that males carrying this introgressed region were consistently fertile; in contrast, males carrying the same segment from d. mauritiana are sterile and suffer from incompatibilities at a minimum of four loci. together with other ... | 1996 | 8913771 |
| high nucleotide sequence variation in a region of low recombination in drosophila simulans is consistent with the background selection model. | we surveyed nucleotide sequence variation at glucose dehydrogenase (gld), in a region of low recombination on chromosome 3r, from a population sample of drosophila simulans. the levels of nucleotide variation were surprisingly high. there was no departure from the expectation of a neutral model for the level of polymorphism, indicating no evidence of a selective sweep in this region. there was a significant deficiency of singleton polymorphisms according to the fu and li test, although tajima an ... | 1996 | 8865667 |
| the genetics of reproductive isolation in the drosophila simulans clade: x vs. autosomal effects and male vs. female effects. | a strong effect of homozygous autosomal regions on reproductive isolation was found for crosses between the species in the drosophila simulans clade. second chromosome regions were introgressed from d. mauritiana and d. sechellia into d. simulans and tested for their homozygous effects on hybrid male and hybrid female sterility and inviability. most introgressions are fertile as heterozygotes, yet produce sterile male offspring when made homozygous. the density of homozygous autosomal factors co ... | 1996 | 8807297 |
| the relationship between structural variation and dysgenic properties of p elements in long-established p-transformed lines of drosophila simulans. | ten lines of drosophila simulans were investigated with respect to p activity, p susceptibility and the number and structure of their p copies, eight years after transformation with the p element. all 10 were found to have reached a steady state. they exhibited varying levels of p activity (from 0 per cent to 96 per cent gd sterility) and, with the exception of one line, were not p-susceptible. in contrast with p element behaviour in d. melanogaster: (i) no relationship was found between the mol ... | 1996 | 8682694 |
| cytoplasmic incompatibility in drosophila simulans: evolving complexity. | | 1996 | 21237786 |
| genetic analysis of a morphological shape difference in the male genitalia of drosophila simulans and d. mauritiana. | two closely related species of drosophila, d. simulans and d. mauritiana, differ markedly in morphology of the posterior lobe of the male genital arch. both size and shape aspects of lobe variation can be quantified by a morphometric descriptor based on elliptical fourier and principal components analyses. the genetic architecture of this quantitative trait (pc1) was investigated by hybridizing inbred lines to produce two backcross populations approximately 200 individuals each, which were analy ... | 1996 | 8846893 |
| geographical variation in insertion site number of retrotransposon 412 in drosophila simulans. | the insertion site number of the retrotransposable element 412 was analyzed in natural populations of drosophila simulans of worldwide origin by in situ hybridization. we observe a gradient in copy number ranging from as high as 23 in europe to 1-10 in south africa, while populations in madagascar and the indian islands, which are the cradle of d. simulans, have only 3-7 copies. we find very different copy numbers in some local populations of australia and the pacific islands (with around 60 cop ... | 1996 | 8642613 |
| molecular structure of the transposable element ninja in drosophila simulans. | genetically unstable dna sequences of 16.1 kb in length were isolated from the white locus of the w(mky) strain of drosophila simulans. this insertional dna has some unique characteristics as a transposon. it is found in high numbers in this strain and its revertant strains w(psm1) and w(cho), but not elsewhere, and the sequence is a tandem triplication of a basic repeating unit. in order to determine the structure of the insert as whole and the functional unit as a transposon, we analyzed nine ... | 1996 | 8925473 |
| genetic studies on premating isolation in drosophila simulans. i.ad. simulans line highly crossable with d. melanogaster. | the s2 line of drosophila simulans, an isofemale line from a natural population at mishima, japan, was found to have high crossability with d. melanogaster. over 80% of the s2 females mated with d. melanogaster males, while only 2.4- 14.2% of control females from other d. simulans lines mated. the reciprocal mating (d. melanogaster female x s2 males) was in normal range (35-50%). the crossability of the f1 females between the s2 and other normal simulans lines was slightly higher than the contro ... | 1995 | 7632441 |
| molecular polymorphism in the period gene of drosophila simulans. | the threonine-glycine (thr-gly) repeat region of the period (per) gene of eight natural populations of drosophila simulans from europe and north africa was analyzed by polymerase chain reaction, dna sequencing and heteroduplex formation. five different length alleles encoding 21, 23, 25 and two different kinds of 24 thr-gly pairs in the uninterrupted repeat were found. in the 3' region flanking the repeat 6 nucleotide substitutions (3 synonymous, 3 replacement) were observed in three different c ... | 1994 | 7851767 |
| nuclear background affects frequency dynamics of mitochondrial dna variants in drosophila simulans. | transplasmic lines, in which the original mitochondrial dna (mtdna) had been completely replaced by the mtdna of the donor, were constructed to test for selection on mtdna variants and to investigate the effects of nuclear-cytoplasmic interactions in drosophila simulans. these lines were used to set up 12 experimental populations putting in competition two mtdna variants with two different starting frequencies. population cages were maintained for 20 generations and periodically sampled to monit ... | 1994 | 8056616 |
| effects of the fourth chromosome on the sterility of hybrids between drosophila simulans and its relatives. | genetic analysis of the fourth chromosome of drosophila simulans shows that it has no effect on either male or female fertility in hybrids with two sibling species, d. mauritiana and d. sechellia. the lack of effect holds even when the d. simulans chromosome is homozygous in a foreign genetic background. the absence of major fourth chromosome "sterility genes" in these hybridizations contrasts with the presence of a fourth-chromosome gene causing complete male sterility in hybrids of the more di ... | 2007 | 8014464 |
| the effects of interspecific y chromosome replacements on hybrid sterility within the drosophila simulans clade. | we attempted to introgress y chromosomes between three sibling species of drosophila: d. simulans, d. sechellia and d. mauritiana. four d. sechellia y chromosomes were introgressed into d. simulans without loss of fertility whereas the four reciprocal introgressions (d. simulans y introgressed into d sechellia) all result in sterility. both reciprocal y introgressions of d. simulans and d. mauritiana (four of each) also result in sterility. compared with d. simulans males, the males with the d. ... | 1993 | 8244006 |
| genetic control of pheromones in drosophila simulans. ii. kété, a locus on the x chromosome. | the production of drosophila cuticular hydrocarbons, including contact pheromones, is under polygenic control. to investigate x-linked loci, ems mutations were induced in drosophila simulans flies. a mutant strain was discovered which in both sexes show a reduction in the biosynthesis of both 7-tricosene (7-t) the species contact pheromone and all other linear hydrocarbons. the locus controlling this effect, kété, is recessive and was localized to i, 18.5. unlike a previously identified gene on ... | 1993 | 8454203 |
| population genetics of polymorphism and divergence. | frequencies of mutant sites are modeled as a poisson random field in two species that share a sufficiently recent common ancestor. the selective effect of the new alleles can be favorable, neutral, or detrimental. the model is applied to the sample configurations of nucleotides in the alcohol dehydrogenase gene (adh) in drosophila simulans and drosophila yakuba. assuming a synonymous mutation rate of 1.5 x 10(-8) per site per year and 10 generations per year, we obtain estimates for the effectiv ... | 1992 | 1459433 |
| dynamics of cytoplasmic incompatibility and mtdna variation in natural drosophila simulans populations. | in drosophila simulans a cytoplasmically transmitted microorganism causes reduced egg hatch when infected males mate with uninfected females. the infection is rapidly spreading northward in california. data on a specific mtdna restriction site length polymorphism show that changes in the frequency of mtdna variants are associated with this spread. all infected flies possess the same mtdna allele, whereas the uninfected flies are polymorphic. given that both paternal inheritance of the infection ... | 1992 | 1468627 |
| xenobiotic-metabolizing enzymes and benzo[a]pyrene metabolism in the benzo[a]pyrene-sensitive mutant strain of drosophila simulans. | basal levels of aryl hydrocarbon hydroxylase, epoxide hydrolase and glutathione s-transferase enzyme activities, cytochrome p-450 content and inducibility of enzymes with phenobarbital were found to be similar in the microsomes of d. simulans mutant strain 364yv, which is sensitive to the toxic and mutagenic effects of benzo[a]pyrene (bp), and of the wild resistant turku strain. in contrast, increases in the rate of bp turnover per molecule of cytochrome p-450, intensity of the hemoprotein band ... | 1992 | 1383701 |
| genetics of sexual isolation in females of the drosophila simulans species complex. | genetic analysis of hybrids between drosophila simulans and d. sechellia shows that sexual isolation in females is caused by at least two genes, one on each major autosome, while the x chromosome has no effect. these results are similar to those of a previous study of hybrids between d. simulans and another sibling species, d. mauritiana. in this latter hybridization, each arm of the second chromosome carries genes causing sexual isolation in females, implying a total divergence of at least thre ... | 1992 | 1452013 |
| location of x-linked polygenic effects causing sterility in male hybrids of drosophila simulans and d. mauritiana. | there is general agreement that hybrid male sterility in drosophila is caused by changes at several (perhaps many) factors, most of them located on the x chromosome. these factors have been generally considered as major genes, each one of them able to bring about sterility by itself. however, the evidence on this last point is not conclusive. in principle, the possibility that they correspond to located polygenic effects instead of genes with a large effect cannot be excluded. this paper shows t ... | 1992 | 1559838 |
| cytoplasmic incompatibility in drosophila populations: influence of assortative mating on symbiont distribution. | cytoplasmic incompatibility is known to occur between strains of both drosophila simulans and d. melanogaster. incompatibility is associated with the infection of drosophila with microorganismal endosymbionts. this paper reports survey work conducted on strains of d. simulans and d. melanogaster from diverse geographical locations finding that infected populations are relatively rare and scattered in their distribution. the distribution of infected populations of d. simulans appears to be at odd ... | 1991 | 1787328 |
| rapid spread of an inherited incompatibility factor in california drosophila. | in drosophila simulans in california, an inherited cytoplasmic incompatibility factor reduces egg hatch when infected males mate with uninfected females. the infection is spreading at a rate of more than 100 km per year; populations in which the infection was rare have become almost completely infected within three years. analyses of the spread using estimates of selection in the field suggest dispersal distances far higher than those found by direct observation of flies. hence, occasional long- ... | 1991 | 1896086 |
| [benzo(a)pyrene pretreatment of drosophila simulans mutant strain results in the induction of aberrant isoform of cytochrome p-450 with increased capacity to metabolize benzo(a)pyrene]. | the basal level of benzo(a)pyrene monooxygenase, epoxide hydrolase and glutathione s-transferase activity as well as the content of cytochrome p-450 were found the same in both compared benzo(a)pyrene (bp) sensitive d. simulans strain 364yv and bp-resistant wild one (turku). phenobarbital pretreatment resulted in the same increase level of these enzyme activities in both strains. bp-pretreatment of 364yv flies decreased the amount of the cytochrome p-450 but raised up the turnover of bp per mole ... | 1991 | 1786390 |
| genetic control of pheromones in drosophila simulans. i. ngbo, a locus on the second chromosome. | 7-tricosene and 7-pentacosene are predominant hydrocarbons on the cuticle of both sexes in drosophila simulans. the pheromonal role of 7-tricosene has been clearly established for conspecific males, while a synergistic effect for 7-pentacosene has been postulated. interstrain variation for the production of both compounds is very marked, but similar for both sexes. the genetic basis of this polymorphism was investigated. a major role was found for the second chromosome, which controls the 7-tric ... | 1991 | 2071017 |
| mitochondrial dna heteroplasmy maintained in natural populations of drosophila simulans in réunion. | mitochondrial dna (mtdna) variation in drosophila simulans was studied to determine whether the cytoplasmic state of mtdna heteroplasmy persists in natural populations in réunion. for this purpose, 172 isofemale lines, newly collected from two local populations, were examined, among which three types of mtdna (siii, siiii and siiii') were found, based on the hpa ii restriction pattern. ten of the lines were heteroplasmic for a combination of siii and siiii, as determined by autoradiography. the ... | 1991 | 2055455 |
| [a mutant strain of drosophila simulans sensitive to the toxic and mutagenic action of benz(a)pyrene]. | a 364 yv strain sensitive to the toxic effect of benzo(a)pyrene (bp) was identified among 49 mutant strains of drosophila simulans. heterozygotes female 364 x male turku obtained by crossing 364 yv species with those of wild bp-resistant turku strain were more sensitive than female turku x male 364 heterozygotes to both toxic and mutagenic effects of the carcinogen in the test of induction of somatic mosaicism with the yellow marker. non-carcinogenic pyrene appeared weekly toxic and non-mutageni ... | 1991 | 1842655 |
| active mariner transposable elements are widespread in natural populations of drosophila simulans. | the occurrence of active, or autonomous, mariner elements was investigated by crossing white-peach mutant drosophila simulans females with wild-type males from various geographic origins. from a total of 194 experimental crosses only 17 failed to produce progeny with eye mosaicism (mos, i.e. pigmented spots in otherwise white-peach eyes). therefore, active mariner elements inducing somatic excision of the copy inserted at the white locus are abundant in all populations sampled. in the experiment ... | 1990 | 1980741 |
| seasonal change in metabolic rate of drosophila simulans. | 1. second-generation descendents of wild-caught female drosophila simulans sturtevant collected at different seasons from gainesville, florida, usa, were reared under a constant temperature and food level but with seasonally variable photoperiods. 2. body weight and metabolic rate, after adjustment to a common body weight, were higher in descendents of flies collected in fall and winter. 3. temperature sensitivity (q10) of metabolic rate was also related to season: higher q10 values were associa ... | 1990 | 1981031 |
| the generation of transplasmic drosophila simulans by cytoplasmic injection: effects of segregation and selection on the perpetuation of mitochondrial dna heteroplasmy. | experimental transplasmic drosophila simulans were obtained through cytoplasm microinjection between eggs carrying different mitochondrial genomes. these genomes (siii and siiii) show a 1.5% difference in their sequences. they produced a large number of heteroplasmic flies in their f1 progeny and several flies were still heteroplasmic at the eighth generation. the distribution of frequencies of mitochondrial genotypes in the offspring of heteroplasmic females suggests that the stochastic process ... | 1989 | 2608025 |
| drosophila simulans cu-zn superoxide dismutase gene sequence. | | 1989 | 2780301 |
| drosophila s virus is a member of the reoviridae family. | the s character of drosophila simulans, the absence or malformation or both of bristles and other cuticular structures, was described by comendador (drosophila inf. serv. 55:26-28, 1980). its characteristics (maternal transmission, low pathogenicity, and sensitivity to temperature) suggested the existence of a virus as the causative agent. indeed, reoviruslike particles were found in subcuticular cells of s individuals, and its association with s phenotypic expression was shown. this virus was c ... | 1989 | 2911113 |
| genetic analysis of x-linked sterility in hybrids between three sibling species of drosophila. | three morphological markers (yellow, miniature, and forked) are used to map the location of x-chromosome segments causing male sterility in drosophila simulans/d. mauritiana and d. simulans/d. sechellia hybrids. in both hybridizations at least three sections of the chromosome contain genes with substantial effects on sterility. this represents the maximum genetic divergence detectable with the three markers, suggesting that the x chromosome contains many loci affecting postzygotic reproductive i ... | 1989 | 2732092 |
| mitochondrial dna variability in drosophila simulans: quasi absence of polymorphism within each of the three cytoplasmic races. | nucleotide variability of mtdna extracted from 144 isofemale lines collected in the whole range of d. simulans was analysed with 10-15 restriction enzymes and 73 lines were studied using one or a few enzymes. all clones were distributed into 3 mitochondrial genomes, sii, siii and siiii. these types are allopatric and can define geographic races. mixed populations occur only in madagascar and réunion, where siii and siiii are found together. among 40 sites detected with 10 enzymes, the variabilit ... | 1988 | 2906636 |
| natural populations of drosophila simulans show great uniformity of the mitochondrial dna restriction map. | the mitochondrial dna of 21 drosophila simulans isofemale lines of different geographic origins was digested with seven restriction endonucleases. all the lines, with one exception for one line and one enzyme, showed the same restriction patterns. the results confirm previous investigations showing great uniformity of the mtdna genome in d. simulans. | 1988 | 3215515 |
| genetics of an unstable white mutant in drosophila simulans: reversion, suppression and somatic instability. | a spontaneous white mutation, white-milky (wmky) of drosophila simulans is moderately unstable and is associated with a 16-kb long dna insertion into the white gene. wmky, which is an unstable mutation found in d. simulans, has been genetically analyzed. among nine spontaneous, partial reversions toward wild type, five were white locus mutations. they are phenotypically different from each other and three show eye color sexual dimorphism indicating a failure of the dosage compensation mechanism. ... | 1988 | 2842227 |
| unidirectional incompatibility in drosophila simulans: inheritance, geographic variation and fitness effects. | in california, drosophila simulans females from some populations (type w) produce relatively few adult progeny when crossed to males from some other populations (type r), but the productivity of the reciprocal cross is comparable to within-population controls. these two incompatibility types are widespread in north america and are also present elsewhere. both types sometimes occur in the same population. type r females always produce type r progeny irrespective of the father's type. however, mat ... | 1988 | 17246430 |