Evolution and genetics of accessory gland transcriptome divergence between Drosophila melanogaster and D. simulans.

Studies of allele-specific expression in interspecific hybrids have provided important insights into gene-regulatory divergence and hybrid incompatibilities. Many such investigations in Drosophila have used transcriptome data from complex mixtures of many tissues or from gonads, however, regulatory divergence may vary widely among species, sexes, and tissues. Thus, we lack sufficiently broad sampling to be confident about the general biological principles of regulatory divergence.

Male-derived transcripts isolated from the mated female reproductive tract in Drosophila melanogaster.

In species with internal fertilization, sperm, and seminal fluid are transferred from male to female during mating. While both sperm and seminal fluid contain various types of molecules, including RNA, the role of most of these molecules in the coordination of fertilization or in other possible functions is poorly understood. In Drosophila, exosomes from the accessory gland, which produces seminal fluid, are transferred to females, but their potential cargoes have not been described.

Identifying candidate de novo genes expressed in the somatic female reproductive tract of Drosophila melanogaster.

Most eukaryotic genes have been vertically transmitted to the present from distant ancestors. However, variable gene number across species indicates that gene gain and loss also occurs. While new genes typically originate as products of duplications and rearrangements of preexisting genes, putative de novo genes-genes born out of ancestrally nongenic sequence-have been identified.

Identifying candidate genes expressed in the somatic female reproductive tract of .

Most eukaryotic genes have been vertically transmitted to the present from distant ancestors. However, variable gene number across species indicates that gene gain and loss also occurs. While new genes typically originate as products of duplications and rearrangements of pre-existing genes, putative genes - genes born out of previously non-genic sequence - have been identified.

Selection and geography shape male reproductive tract transcriptomes in Drosophila melanogaster.

Transcriptome analysis of several animal clades suggests that male reproductive tract gene expression evolves quickly. However, the factors influencing the abundance and distribution of within-species variation, the ultimate source of interspecific divergence, are poorly known. Drosophila melanogaster, an ancestrally African species that has recently spread throughout the world and colonized the Americas in the last roughly 100 years, exhibits phenotypic and genetic latitudinal clines on multiple continents, consistent with a role for spatially varying selection in shaping its biology.