Project description:The Drosophila nasuta nasuta (D. n. nasuta) is a member of nasuta subgroup of immigrans species group of Drosophila widely distributed across South-East Asia and central to Southern Africa. It displays morphological similarities with other members of the nasuta subgroup with which it has a recent divergence history. The genomic DNA of D. n. nasuta Coorg strain was paired-end sequenced using Illumina HiSeq 2500 technology to obtain a draft genome assembly of 145.64 Mb. The generated assembly retrieved 93.6% of the conserved dipteran BUSCO orthologs. Approximately 85% of the ab initio predicted proteins exhibit sequence similarity to the proteins of D. albomicans which is the closest annotated species. This draft genome sequence is a valuable resource to Drosophila geneticists and evolutionary biologists to understand molecular organisation of the genome and its evolution during early stages of speciation.
Project description:Cytorace-3 is a laboratory evolved hybrid lineage of Drosophila nasuta nasuta males and Drosophila nasuta albomicans females currently passing ~850 generations. To assess interracial hybridization effects on gene expression in Cytorace-3 we profiled the transcriptomes of mature ovaries and testes by employing Illumina sequencing technology and de novo transcriptome assembling strategies. We found 26% of the ovarian, and 14% of testis genes to be differentially expressed in Cytorace-3 relative to the expressed genes in the parental gonadal transcriptomes. About 5% of genes exhibited additive gene expression pattern in the ovary and 3% in the testis, while the remaining genes were misexpressed in Cytorace-3. Nearly 772 of these misexpressed genes in the ovary and 413 in the testis were either over- or under-dominant. Genes following D. n. nasuta dominance was twice (270 genes) than D. n. albomicans dominance (133 genes) in the ovary. In contrast, only 105 genes showed D. n. nasuta dominance and 207 showed D. n. albomicans dominance in testis transcriptome. Of the six expression inheritance patterns, conserved inheritance pattern was predominant for both ovary (73%) and testis (85%) in Cytorace-3. This study is the first to provide an overview of the expression divergence and inheritance patterns of the transcriptomes in an independently evolving distinct hybrid lineage of Drosophila. This recorded expression divergence in Cytorace-3 surpasses that between parental lineages illustrating the strong impact of hybridization driving rapid gene expression changes.
