Genomic Islands of Divergence Between Drosophila yakuba Subspecies are Predominantly Driven by Chromosomal Inversions and the Recombination Landscape.

During the early stages of local adaptation and speciation, genetic differences tend to accumulate at certain regions of the genome leading to the formation of genomic islands of divergence (GIDs). This pattern may be due to selection and/or difference in the rate of recombination. Here, we investigate the possible causes of GIDs in Drosophila yakuba mayottensis, and reconfirm using field collection its association with toxic noni (Morinda citrifolia) fruits on the Mayotte island.

Saltational Episodes of Reticulate Evolution in the Drosophila saltans Species Group.

Phylogenomics reveals reticulate evolution to be widespread across taxa, but whether reticulation is due to low statistical power or it is a true evolutionary pattern remains a field of study. Here, we investigate the phylogeny and quantify reticulation in the Drosophila saltans species group, a Neotropical clade of the subgenus Sophophora comprising 23 species whose relationships have long been problematic. Phylogenetic analyses revealed conflicting topologies between the X chromosome, autosomes and the mitochondria.

The genome of the blind bee louse fly reveals deep convergences with its social host and illuminates Drosophila origins.

Social insects' nests harbor intruders known as inquilines, which are usually related to their hosts. However, distant non-social inquilines may also show convergences with their hosts, although the underlying genomic changes remain unclear. We analyzed the genome of the wingless and blind bee louse fly Braula coeca, an inquiline kleptoparasite of the western honey bee, Apis mellifera.

Long-term evolution of quantitative traits in the Drosophila melanogaster species subgroup.

Quantitative genetics aims at untangling the genetic and environmental effects on phenotypic variation. Trait heritability, which summarizes the relative importance of genetic effects, is estimated at the intraspecific level, but theory predicts that heritability could influence long-term evolution of quantitative traits. The phylogenetic signal concept bears resemblance to heritability and it has often been called species-level heritability.

A standardized nomenclature and atlas of the female terminalia of .

The model organism has become a focal system for investigations of rapidly evolving genital morphology as well as the development and functions of insect reproductive structures. To follow up on a previous paper outlining unifying terminology for the structures of the male terminalia in this species, we offer here a detailed description of the female terminalia of . Informative diagrams and micrographs are presented to provide a comprehensive overview of the external and internal reproductive structures of females.

Evolution of assortative mating following selective introgression of pigmentation genes between two species.

Adaptive introgression is ubiquitous in animals, but experimental support for its role in driving speciation remains scarce. In the absence of conscious selection, admixed laboratory strains of asymmetrically and progressively lose alleles from one parental species and reproductive isolation against the predominant parent ceases after 10 generations. Here, we selectively introgressed during 1 year light pigmentation genes of .

Signature of climatic differentiation on mitochondrial DNA of .

Pleistocene climatic changes have played a major role in the evolution of Brazilian Atlantic Forest and South America biodiversity but their impacts on the genetic structure of widely distributed species remain unclear. Here, we investigate mitochondrial DNA (mtDNA) diversity in 21 geographical populations of , Nucleotide sequences of the cytochrome C oxidase subunits I and II genes ( and , respectively from 163 individuals, showed a significant north-south structure, in spite of an overall low level of variation. The haplotypes clustered in three groups that showed strong correlations with geographical and climatic variables, suggesting that local adaptations might have contributed to differentiation within the species.

Resolving between novelty and homology in the rapidly evolving phallus of Drosophila.

The genitalia present some of the most rapidly evolving anatomical structures in the animal kingdom, possessing a variety of parts that can distinguish recently diverged species. In the Drosophila melanogaster group, the phallus is adorned with several processes, pointed outgrowths, that are similar in size and shape between species. However, the complex three-dimensional nature of the phallus can obscure the exact connection points of each process.

Integrative taxonomy and a new species description in the sturtevanti subgroup of the Drosophila saltans group (Diptera: Drosophilidae).

Although the biological concept of species is well established in animals, sometimes the decision about the specific status of a new species is difficult and hence requires support of an integrative analysis of several character sets. To date, the species Drosophila sturtevanti, D. magalhaesi, D.

Soft Selective Sweep on Chemosensory Genes Correlates with Ancestral Preference for Toxic Noni in a Specialist Population.

Understanding how organisms adapt to environmental changes is a major question in evolution and ecology. In particular, the role of ancestral variation in rapid adaptation remains unclear because its trace on genetic variation, known as soft selective sweep, is often hardly recognizable from genome-wide selection scans. Here, we investigate the evolution of chemosensory genes in , a specialist subspecies on toxic noni () fruits on the island of Mayotte.

A standardized nomenclature and atlas of the male terminalia of .

Animal terminalia represent some of the most diverse and rapidly evolving structures in the animal kingdom, and for this reason have been a mainstay in the taxonomic description of species. The terminalia of , with its wide range of experimental tools, have recently become the focus of increased interest in the fields of development, evolution, and behavior. However, studies from different disciplines have often used discrepant terminologies for the same anatomical structures.

Quantifying the extent of morphological homoplasy: A phylogenetic analysis of 490 characters in .

Homoplasy is a fundamental phenomenon in evolutionary biology but an appraisal of its extent at the morphological level is still lacking. Here, we analyzed the evolution of 490 morphological characters conceptualized among 56 drosophilid species. We found that two thirds of morphological changes were homoplastic and that the level of homoplasy depended on the stage of development and the type of the organ, with the adult terminalia being the least homoplastic.

Correlated Evolution of Two Copulatory Organs via a Single cis-Regulatory Nucleotide Change.

Diverse traits often covary between species [1-3]. The possibility that a single mutation could contribute to the evolution of several characters between species [3] is rarely investigated as relatively few cases are dissected at the nucleotide level. Drosophila santomea has evolved additional sex comb sensory teeth on its legs and has lost two sensory bristles on its genitalia.

A Variable Genetic Architecture of Melanic Evolution in Drosophila melanogaster.

Unraveling the genetic architecture of adaptive phenotypic divergence is a fundamental quest in evolutionary biology. In Drosophila melanogaster, high-altitude melanism has evolved in separate mountain ranges in sub-Saharan Africa, potentially as an adaptation to UV intensity. We investigated the genetic basis of this melanism in three populations using a new bulk segregant analysis mapping method.

Drosophila yakuba mayottensis, a new model for the study of incipient ecological speciation.

A full understanding of how ecological factors drive the fixation of genetic changes during speciation is obscured by the lack of appropriate models with clear natural history and powerful genetic toolkits. In a recent study, we described an early stage of ecological speciation in a population of the generalist species Drosophila yakuba (melanogaster subgroup) on the island of Mayotte (Indian Ocean). On this island, flies are strongly associated with the toxic fruits of noni (Morinda citrifolia) and show a partial degree of pre-zygotic reproductive isolation.

Life history evolution and cellular mechanisms associated with increased size in high-altitude Drosophila.

Understanding the physiological and genetic basis of growth and body size variation has wide-ranging implications, from cancer and metabolic disease to the genetics of complex traits. We examined the evolution of body and wing size in high-altitude Drosophila melanogaster from Ethiopia, flies with larger size than any previously known population. Specifically, we sought to identify life history characteristics and cellular mechanisms that may have facilitated size evolution.

The pdm3 Locus Is a Hotspot for Recurrent Evolution of Female-Limited Color Dimorphism in Drosophila.

Sex-limited polymorphisms are an intriguing form of sexual dimorphism that offer unique opportunities to reconstruct the evolutionary changes that decouple male and female traits encoded by a shared genome. We investigated the genetic basis of a Mendelian female-limited color dimorphism (FLCD) that segregates in natural populations of more than 20 species of the Drosophila montium subgroup. In these species, females have alternative abdominal color morphs, light and dark, whereas males have only one color morph in each species.

Recurrent specialization on a toxic fruit in an island Drosophila population.

Recurrent specialization on similar host plants offers a unique opportunity to unravel the evolutionary and genetic mechanisms underlying dietary shifts. Recent studies have focused on ecological races belonging to the same species, but it is hard in many cases to untangle the role of adaptive introgression versus distinct mutations in facilitating recurrent evolution. We discovered on the island of Mayotte a population of the generalist fly Drosophila yakuba that is strictly associated with noni (Morinda citrifolia).

Ancient balancing selection at tan underlies female colour dimorphism in Drosophila erecta.

Dimorphic traits are ubiquitous in nature, but the evolutionary factors leading to dimorphism are largely unclear. We investigate a potential case of sexual mimicry in Drosophila erecta, in which females show contrasting resemblance to males. We map the genetic basis of this sex-limited colour dimorphism to a region containing the gene tan.

Pigmentation in Drosophila melanogaster reaches its maximum in Ethiopia and correlates most strongly with ultra-violet radiation in sub-Saharan Africa.

Background: Pigmentation has a long history of investigation in evolutionary biology. In Drosophila melanogaster, latitudinal and altitudinal clines have been found but their underlying causes remain unclear. Moreover, most studies were conducted on cosmopolitan populations which have a relatively low level of genetic structure and diversity compared to sub-Saharan African populations.

Coevolution between male and female genitalia in the Drosophila melanogaster species subgroup.

In contrast to male genitalia that typically exhibit patterns of rapid and divergent evolution among internally fertilizing animals, female genitalia have been less well studied and are generally thought to evolve slowly among closely-related species. As a result, few cases of male-female genital coevolution have been documented. In Drosophila, female copulatory structures have been claimed to be mostly invariant compared to male structures.

The Drosophilidae (Diptera) of the Scattered Islands, with the description of a novel association with Leptadenia madagascariensis Decne. (Apocynaceae).

Thirteen drosophilid species belonging to seven genera and two subfamilies are reported from three coral islands (namely Europa, Juan de Nova and Glorioso) that belong to the Scattered Islands in the Indian Ocean. Five species are cosmopolitan and five are African. Three are endemic to the insular Western Indian Ocean, including a presumably new Scaptodrosophila species.

Scratching for food: an original feeding behavior in an African flower breeding Drosophila.

Drosophila suma is a flower breeding species widespread in the Afrotropical region. We describe an original and so far unique feeding behavior in that species. Strong black spines on the fore tarsus of both sexes are used for scratching the surface of the petals: the juice pouring out from the scratched cells is immediately ingested and this might be the only source of food.

Thermal phenotypic plasticity of body size in Drosophila melanogaster: sexual dimorphism and genetic correlations.

Thirty isofemale lines collected in three different years from the same wild French population were grown at seven different temperatures (12-31 °C). Two linear measures, wing and thorax length, were taken on 10 females and 10 males of each line at each temperature, also enabling the calculation of the wing/thorax (W/T) ratio, a shape index related to wing loading. Genetic correlations were calculated using family means.

The genus Drosophila as a model for testing tree- and character-based methods of species identification using DNA barcoding.

DNA barcoding has recently been proposed as a promising tool for the (1) rapid assignment of unknown samples to described species by non-expert workers and (2) a potential method of new species discovery based on degree of DNA sequence divergence. Two broad methods have been used, one based on degree of DNA sequence variation, within and between species and another requiring the recovery of species as discrete clades (monophyly) on a phylogenetic tree. An alternative method relies on the identification of a set of specific diagnostic nucleotides for a given species (characters).