Gene expression and alternative splicing dynamics are perturbed in female head transcriptomes following heterospecific copulation.

Background: Despite the growing interest in the female side of copulatory interactions, the roles played by differential expression and alternative splicing mechanisms of pre-RNA on tissues outside of the reproductive tract have remained largely unknown. Here we addressed these questions in the context of con- vs heterospecific matings between Drosophila mojavensis and its sister species, D. arizonae.

Host use and host shifts in Drosophila.

Over a thousand Drosophila species have radiated onto a wide range of feeding and breeding sites. These radiations involve adaptations for locating, accepting, and growing in hosts with highly differing characteristics. In a number of species, owing to the availability of sequenced genomes, particular steps in host specialization and genes that control them, are being identified.

Developmental and Transcriptomal Responses to Seasonal Dietary Shifts in the Cactophilic Drosophila mojavensis of North America.

Drosophila mojavensis normally breeds in necrotic columnar cactus, but they also feed and breed in Opuntia fruit (prickly pear) which serves as a seasonal resource. The prickly pear fruits (PPFs) are much different chemically from cacti, mainly in their free sugars and lipid content, raising the question of the effects of this seasonal shift on fitness and on gene expression. Here we reared 3 isofemale strains of D.

Lipidomic profiles of Drosophila melanogaster and cactophilic fly species: models of human metabolic diseases.

The metabolic syndrome (MetS) is associated with serious diseases and represents an important threat for global public health. The common fruit fly (Drosophila melanogaster) has served as a model organism to study physiological processes of the MetS, because central metabolic pathways are conserved among species, and because the flies are easy to cultivate in a laboratory. In nature, D.

Transcriptional responses of ecologically diverse Drosophila species to larval diets differing in relative sugar and protein ratios.

We utilized three ecologically diverse Drosophila species to explore the influence of ecological adaptation on transcriptomic responses to isocaloric diets differing in their relative proportions of protein to sugar. Drosophila melanogaster, a cosmopolitan species that breeds in decaying fruit, exemplifies individuals long exposed to a Western diet higher in sugar, while the natural diet of the cactophilic D. mojavensis, is much lower in carbohydrates.

Evolution of GSTD1 in Cactophilic Drosophila.

GSTD1 is an insect glutathione S-transferase that has received considerable attention because of its role in detoxification of xenobiotic compounds, specifically pesticides and plant allelochemicals involved in detoxification, or in the use of some substrates as a nutritional source. GSTD1 has been implicated in the adaptation to a new cactus host in Drosophila mojavensis and thus constitutes an interesting candidate to study ecological genetics of adaptation in Drosophila. We conducted population genetic and molecular evolution analyses of the GstD1 gene in the context of association with different cactus hosts (Opuntia sp.

Early events in speciation: Cryptic species of .

Understanding the earliest events in speciation remains a major challenge in evolutionary biology. Thus identifying species whose populations are beginning to diverge can provide useful systems to study the process of speciation. , a cactophilic fruit fly species with a broad distribution in North America, has long been assumed to be a single species owing to its morphological uniformity.

Population Genetics of Overwintering Monarch Butterflies, Danaus plexippus (Linnaeus), from Central Mexico Inferred from Mitochondrial DNA and Microsatellite Markers.

Population genetic variation and demographic history in Danaus plexippus (L.), from Mexico were assessed based on analyses of mitochondrial cytochrome c oxidase subunit I (COI; 658 bp) and subunit II (COII; 503 bp) gene segments and 7 microsatellite loci. The sample of 133 individuals included both migratory monarchs, mainly from 4 overwintering sites within the Monarch Butterfly Biosphere Reserve (MBBR) in central Mexico (states of Michoacán and México), and a nonmigratory population from Irapuato, Guanajuato.

Ectoparasitic mites and their Drosophila hosts.

Only two parasite interactions are known for Drosophila to date: Allantonematid nematodes associated with mycophagous Drosophilids and the ectoparasitic mite Macrocheles subbadius with the Sonoran Desert endemic Drosophila nigrospiracula. Unlike the nematode-Drosophila association, breadth of mite parasitism on Drosophila species is unknown. As M.

Genome Evolution in Three Species of Cactophilic Drosophila.

We report genomes of two species of cactophilic Drosophila: Drosophila arizonae and D. navojoa These two are the closest relatives of D. mojavensis, forming the D.

The secret lives of Drosophila flies.

Flies of the genus Drosophila, and particularly those of the species Drosophila melanogaster, are best known as laboratory organisms. As with all model organisms, they were domesticated for empirical studies, but they also continue to exist as wild populations. Decades of research on these flies in the laboratory have produced astounding and important insights into basic biological processes, but we have only scratched the surface of what they have to offer as research organisms.

Parents Without Partners: Drosophila as a Model for Understanding the Mechanisms and Evolution of Parthenogenesis.

Of 40 Drosophila species screened to date, a majority have shown some ability to at least initiate parthenogenetic development. In one case, Drosophila mangebeirai, natural populations are entirely female, making it the only obligate parthenogenetic species of Drosophila Only a few of the species that exhibit the ability to undergo early embryonic development of unfertilized eggs successfully respond to selection for parthenogenetic production of adult flies. Laboratory strains of parthenogenetic Drosophila mercatorum have been created by artificial selection on multiple occasions, but the proportion of eggs undergoing development to adulthood has never exceeded 8%.

"Cost" of virginity in wild Drosophila melanogaster females.

Laboratory studies have revealed a significant "cost of mating" to Drosophila melanogaster females in the form of reduced longevity. The effect is attributable to nonsperm components of the ejaculate. Female D.

The 19 genomes of Drosophila: a BAC library resource for genus-wide and genome-scale comparative evolutionary research.

The genus Drosophila has been the subject of intense comparative phylogenomics characterization to provide insights into genome evolution under diverse biological and ecological contexts and to functionally annotate the Drosophila melanogaster genome, a model system for animal and insect genetics. Recent sequencing of 11 additional Drosophila species from various divergence points of the genus is a first step in this direction. However, to fully reap the benefits of this resource, the Drosophila community is faced with two critical needs: i.

Sexual isolation and mating propensity among allopatric Drosophila mettleri populations.

Drosophila mettleri is found in deserts of North America breeding in soil soaked by the juices of necrotic cacti. Saguaro (Carnegiea gigantea) and cardón (Pachycereus pringlei) are the usual host cacti in Mexico and Arizona, while prickly pear (Opuntia spp.) is used by an isolated population on Santa Catalina Island off the southern California Coast.

Drosophila biology in the genomic age.

Over the course of the past century, flies in the family Drosophilidae have been important models for understanding genetic, developmental, cellular, ecological, and evolutionary processes. Full genome sequences from a total of 12 species promise to extend this work by facilitating comparative studies of gene expression, of molecules such as proteins, of developmental mechanisms, and of ecological adaptation. Here we review basic biological and ecological information of the species whose genomes have recently been completely sequenced in the context of current research.

Sperm fate and function in reproductive isolation in Drosophila.

Central to the study of speciation is the identification of the isolating mechanisms that reduce gene flow. Of special interest are those isolating mechanisms that are the earliest to arise. Sperm fate and function play a major role in two distinct types of reproductive isolation in the genus Drosophila.

Sympatry, allopatry and sexual isolation between Drosophila mojavensis and D. arizonae.

Populations of the North American cactophilic fruitfly Drosophila mojavensis and its sibling species D. arizonae exist both in sympatry and in allopatry. Females of D.

Evolutionary genetics of reproductive behavior in Drosophila: connecting the dots.

Species of the genus Drosophila exhibit enormous variation in all of their reproductive behaviors: resource use and specialization, courtship signaling, sperm utilization, and female remating. The genetic bases of this variability and its evolution are poorly understood. At the same time, Drosophila comparative genomics now has developed to a point at which approaches previously only possible with D.

Perspective: female remating, operational sex ratio, and the arena of sexual selection in Drosophila species.

As commonly observed among closely related species within a variety of taxa, Drosophila species differ considerably in whether they exhibit sexual dimorphism in coloration or morphology. Those Drosophila species in which male external sexual characters are minimal or absent tend, instead, to have exaggerated ejaculate traits such as sperm gigantism or seminal nutrient donations. Underlying explanations for the interspecific differences in the presence of external morphological sexual dimorphism versus exaggerated ejaculate traits are addressed here by examining the opportunity for sexual selection on males to occur before versus after mating in 21 species of Drosophila.

Efficiency of gamete usage in nature: sperm storage, fertilization and polyspermy.

Gamete production for both males and females can be energetically expensive such that selection should maximize fertilization opportunities while minimizing fertilization costs. In laboratory studies of Drosophila reproduction, however, the failure of eggs to yield adult progeny can be quite high, suggesting that female control over gamete utilization is surprisingly inefficient. We examined gamete utilization in D.