Publications

TitleAbstractYear
Filter
PMID
Filter
divergence between drosophila santomea and allopatric or sympatric populations of d. yakuba using paralogous amylase genes and migration scenarios along the cameroon volcanic line.we have used two paralogous genes (amyrel and amy) of the amylase multigene family to reconstruct the phylogeny of the nine drosophila melanogaster subgroup sister species, including d. santomea, the newly discovered endemic from são tomé island. the evolutionary divergence of these genes is of special interest as it is suspected to result from physiological evolution via gene duplication. this paper describes the relationship between the geographical origin of the various strains and the patter ...200111298976
evolutionary novelties in islands: drosophila santomea, a new melanogaster sister species from são tomé.the finding of new melanogaster sister species may help us in understanding more about how the emergence of genetic novelties, particularly in insular habitats, can result in speciation. here we report on the discovery of drosophila santomea, which is the first melanogaster sibling found off west-equatorial africa, on são tomé, one of the gulf of guinea islands. although the eight other melanogaster sister species are remarkably conservative in their morphology except for their terminalia, the n ...200011007323
the magnitude of behavioral isolation is affected by characteristics of the mating community.gene exchange between species occurs in areas of secondary contact, where two species have the opportunity to hybridize. if heterospecific males are more common than conspecific males, females will experience more encounters with males of other species. these encounters might increase the likelihood of heterospecific matings, and lead to the production of hybrid progeny. i studied the mating behavior of two pairs of sibling species endemic to africa: drosophila yakuba/drosophila santomea and dro ...201425165530
genetics of a difference in pigmentation between drosophila yakuba and drosophila santomea.drosophila yakuba is a species widespread in africa, whereas d. santomea, its newly discovered sister species, is endemic to the volcanic island of são tomé in the gulf of guinea. drosophila santomea probably formed after colonization of the island by its common ancestor with d. yakuba. the two species differ strikingly in pigmentation: d. santomea, unlike the other eight species in the d. melanogaster subgroup, almost completely lacks dark abdominal pigmentation. d. yakuba shows the sexually di ...200212487356
temperature-based extrinsic reproductive isolation in two species of drosophila.drosophila santomea and d. yakuba are sister species that live on the african volcanic island of são tomé, where they are ecologically isolated: d. yakuba inhabits low-altitude open and semiopen habitats while d. santomea lives in higher-elevation rain and mist forest. to determine whether this spatial isolation reflected differential preference for and tolerance of temperature, we estimated fitness components of both species at different temperatures as well as their behavioral preference for c ...200919087181
sexual isolation between two sibling species with overlapping ranges: drosophila santomea and drosophila yakuba.drosophila yakuba is widespread in africa, whereas d. santomea, its newly discovered sister species, is endemic to the volcanic island of são tomé in the gulf of guinea. drosophila santomea probably formed after colonization of the island by a d. yakuba-like ancestor. the species presently have overlapping ranges on the mountain pico do são tomé, with some hybridization occurring in this region. sexual isolation between the species is uniformly high regardless of the source of the populations, a ...200212583583
sexual isolation and cuticular hydrocarbon differences between drosophila santomea and drosophila yakuba.drosophila santomea and drosophila yakuba are two sister species inhabiting saõ tomé island. previous studies showed that both species display strong reproductive isolation, although they can produce a few viable hybrids. our study tried to understand the mechanism of this ethological isolation between two allopatric strains. a strong sexual isolation was confirmed, with a marked asymmetry. comparisons of latency times to either courtship or copulation suggest that males do not discriminate fema ...200516132336
the genetic basis of prezygotic reproductive isolation between drosophila santomea and d. yakuba due to mating preference.sexual isolating mechanisms that act before fertilization are often considered the most important genetic barriers leading to speciation in animals. while 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 drosophila sa ...200616510787
the genetic basis of postzygotic reproductive isolation between drosophila santomea and d. yakuba due to hybrid male sterility.a major unresolved challenge of evolutionary biology is to determine the nature of the allelic variants of "speciation genes": those alleles whose interaction produces inviable or infertile interspecific hybrids but does not reduce fitness in pure species. here we map quantitative trait loci (qtl) affecting fertility of male hybrids between d. yakuba and its recently discovered sibling species, d. santomea. we mapped three to four x chromosome qtl and two autosomal qtl with large effects on the ...200616510788
impact of experimental design on drosophila sexual isolation studies: direct effects and comparison to field hybridization data.many studies of speciation rely critically on estimates of sexual isolation obtained in the laboratory. here we examine the sensitivity of sexual isolation to alterations in experimental design and mating environment in two sister species of drosophila, d. santomea and d. yakuba. we use a newly devised measure of mating frequencies that is able to disentangle sexual isolation from species differences in mating propensity. variation in fly density, presence or absence of a quasi-natural environme ...200516526506
extensive introgression of mitochondrial dna relative to nuclear genes in the drosophila yakuba species group.studies of gene flow between recently diverged species can illuminate the role of natural selection in the formation of new species. drosophila santomea and d. yakuba are recently diverged, partially reproductively isolated species that continue to hybridize in the wild, and appear to be reproductively isolated from the more distantly related species d. teissieri. we examine patterns of nucleotide polymorphism and divergence in these three species at multiple x-linked, y-linked, and mitochondria ...200616610321
the evolution of gene regulation underlies a morphological difference between two drosophila sister species.understanding the mechanisms underlying the morphological divergence of species is one of the central goals of evolutionary biology. here, we analyze the genetic and molecular bases of the divergence of body pigmentation patterns between drosophila yakuba and its sister species drosophila santomea. we found that loss of pigmentation in d. santomea involved the selective loss of expression of the tan and yellow pigmentation genes. we demonstrate that tan gene expression was eliminated through the ...200818329365
little effect of the tan locus on pigmentation in female hybrids between drosophila santomea and d. melanogaster.previous work on drosophila santomea suggested that its absence of abdominal pigmentation, compared to the other darkly pigmented species, is based on mutations in the cis-regulatory region of tan, inactivating the expression of that gene in the abdomen of d. santomea males and females. our discovery that d. santomea males can produce viable hybrids when mated to d. melanogaster females enables us to use the armamentarium of genetic tools in the latter species to study the genetic basis of this ...200920005810
evolution of the tan locus contributed to pigment loss in drosophila santomea: a response to matute et al.we have shown previously that the loss of abdominal pigmentation in d. santomea relative to its sister species d. yakuba resulted, in part, from cis-regulatory mutations at the tan locus. matute et al. claim, based solely upon extrapolation from genetic crosses of d. santomea and d. melanogaster, a much more divergent species, that at least four x chromosome regions but not tan are responsible for pigmentation differences. here, we provide additional evidence from introgressions of d. yakuba gen ...200920005811
assessing constraints on the path of regulatory sequence evolution.structural and functional constraints are known to play a major role in restricting the path of evolution of protein activities. however, constraints acting on evolving transcriptional regulatory sequences, e.g. enhancers, are largely unknown. recently, we elucidated how a novel expression pattern of the neprilysin-1 (nep1) gene in the optic lobe of drosophila santomea evolved via co-option of existing enhancer activities. drosophila santomea, which has diverged from drosophila yakuba by approxi ...201324218638
noisy neighbors can hamper the evolution of reproductive isolation by reinforcing selection.reinforcement is the process by which selection against hybridization leads to an increase in reproductive isolation. the influence of reinforcing selection can be detected when sympatric individuals (those from areas of secondary contact) show a higher degree of prezygotic isolation than allopatric individuals (those from areas outside each other's range). in areas of secondary contact with drosophila santomea, drosophila yakuba females show reinforcement of gametic isolation but not behavioral ...201525616143
gene flow between drosophila yakuba and drosophila santomea in subunit v of cytochrome c oxidase: a potential case of cytonuclear cointrogression.introgression is the effective exchange of genetic information between species through natural hybridization. previous genetic analyses of the drosophila yakuba-d. santomea hybrid zone showed that the mitochondrial genome of d. yakuba had introgressed into d. santomea and completely replaced its native form. since mitochondrial proteins work intimately with nuclear-encoded proteins in the oxidative phosphorylation (oxphos) pathway, we hypothesized that some nuclear genes in oxphos cointrogressed ...201526155926
intrinsic reproductive isolation between two sister species of drosophila.drosophila santomea and d. yakuba are sister species that live on the volcanic african island of são tomé. previous work has revealed several barriers to gene flow, including sexual isolation, hybrid sterility, and "extrinsic" ecological isolation based on differential adaptation to and preference for temperature. here, we describe several new "intrinsic" barriers to gene flow-barriers that do not depend on the species' ecology. these include reduced egg number, reduced egg hatchability, and fas ...201019891626
evolutionary origin of a novel gene expression pattern through co-option of the latent activities of existing regulatory sequences.spatiotemporal changes in gene expression underlie many evolutionary novelties in nature. however, the evolutionary origins of novel expression patterns, and the transcriptional control elements ("enhancers") that govern them, remain unclear. here, we sought to explore the molecular genetic mechanisms by which new enhancers arise. we undertook a survey of closely related drosophila species to identify recently evolved novel gene expression patterns and traced their evolutionary history. analyses ...201121593416
tinker where the tinkering's good.do general principles govern the genetic causes of phenotypic evolution? one promising idea is that mutations in cis-regulatory regions play a predominant role in phenotypic evolution because they can alter gene activity without causing pleiotropic effects. recent evidence that revealed the genetic basis of pigmentation pattern evolution in drosophila santomea supports this notion. multiple mutations that disrupt an abdominal enhancer of the pleiotropic gene tan partly explain the reduced pigmen ...200818514359
sequential adaptive introgression of the mitochondrial genome in drosophila yakuba and drosophila santomea.interspecific hybridization provides the unique opportunity for species to tap into genetic variation present in a closely related species and potentially take advantage of beneficial alleles. it has become increasingly clear that when hybridization occurs, mitochondrial dna (mtdna) often crosses species boundaries, raising the possibility that it could serve as a recurrent target of natural selection and source of species' adaptations. here we report the sequences of 46 complete mitochondrial g ...201424460929
an intron loss of dfak gene in species of the drosophila melanogaster subgroup and phylogenetic analysis.drosophila focal adhesion kinase (dfak) gene is a single-copy nuclear gene. previous study revealed that drosophila melanogaster and drosophila simulans had lost an intron precisely within the tyrosine kinase (tyk) domain of this gene. however, this did not happen in several other drosophila species, including drosophila elegans, drosophila ficusphila, drosophila biarmipes, drosophila jambulina, drosophila prostipennis, drosophila takahashii, and drosophila pseudoobscura. in the current study, h ...200918310070
recurrent positive selection of the drosophila hybrid incompatibility gene hmr.lethality in hybrids between drosophila melanogaster and its sibling species drosophila simulans is caused in part by the interaction of the genes hybrid male rescue (hmr) and lethal hybrid rescue (lhr). hmr and lhr have diverged under positive selection in the hybridizing species. here we test whether positive selection of hmr is confined only to d. melanogaster and d. simulans. we find that hmr has continued to diverge under recurrent positive selection between the sibling species d. simulans ...200818755760
a major locus controls a genital shape difference involved in reproductive isolation between drosophila yakuba and drosophila santomea.rapid evolution of genitalia shape, a widespread phenomenon in animals with internal fertilization, offers the opportunity to dissect the genetic architecture of morphological evolution linked to sexual selection and speciation. most quantitative trait loci (qtl) mapping studies of genitalia divergence have focused on drosophila melanogaster and its three most closely related species, d. simulans, d. mauritiana, and d. sechellia, and have suggested that the genetic basis of genitalia evolution i ...201526511499
Displaying items 1 - 24 of 24