Project description:In order to test the hypothesis that adult hybrid misexpression results from the cascading effect of earlier-expressed developmentally important improperly regulated genes, as well as address whether Von Baer’s 3rd law (suggesting that earlier stages of development should be more similar between species than later stages) holds at the level of gene expression, we conducted whole-transcriptome Drosophila melanogaster cDNA microarray-based expression profiling of males of D. melanogaster, D. sechellia, and D. simulans, at four synchronized developmental time-points (3rd instar larval [larval], early pupal, late pupal, and newly-emerged adult [adult]). D. simulans and D. sechellia shared a most recent common ancestor (MRCA) ~0.5 to 1.0 million years ago (MYA) and form a clade that shared an MRCA with D. melanogaster approximately 5.4 MYA. In addition, we also performed the same analysis on the male interspecific F1 hybrids of the D. simulans (♀) × D. sechellia (♂) cross.
Project description:Species often produce sterile hybrids early in their evolutionary divergence, and some evidence suggests that hybrid sterility may be associated with deviations or disruptions in gene expression. In support of this idea, many studies have shown that a high proportion of male-biased genes are underexpressed compared to non-sex-biased genes in sterile F1 male hybrids of Drosophila species. In this study, we examined and compared patterns of misexpression in F1 hybrid male third instar larvae of Drosophila simulans and its sibling species, D. mauritiana. We analyzed hybrids using custom cDNA arrays we developed from RT-PCRs of spermatogenesis-related transcripts from these species and another sibling species (D. sechellia). The results from a commercial genome-wide array and custom chip for adults of this species pair, from the custom chip and the genome-wide chip for adults of the D. simulans-D. sechellia species pair, and from the larvae of the D. simulans-D. sechellia species pair, are presented separately. Keywords: Comparison of pure-species Drosophila expression to hybrid expression
Project description:These arrays measure gene expression across eight Y introgression lines in Drosophila simulans. Four lines (Ya19, Ya23, Ya24, Ya26) carry a D. simulans Y chromosome (from a Cameroon population) and four lines (Sec01, Sec03, Sec08, Sec27) carry a D. sechellia Y chromosome. All lines are otherwise identical with a D. simulans background (UCSD stock center line 14021-0251.092).
