The Drosophila Early Ovarian Transcriptome Provides Insight to the Molecular Causes of Recombination Rate Variation. Andrew Adrian^1,2, Josep Comeron^1,3. 1) Biology, University of Iowa, Iowa City, IA; 2) Interdisciplinary Graduate Program in Informatics, University of Iowa, IA; 3) Interdisiplinary Program in Genetics, University of Iowa, IA.

   Evidence in yeast indicates that elevated expression is correlated with increased levels of double-strand breaks (DSB). Our recent studies of recombination maps across the D.melanogaster genome also indicate an excess of DSBs within annotated transcripts relative to intergenic sequences. As cells that undergo DSB formation (and recombination via DSB-repair) represent only a small fraction of the whole individual or even the gonadal tissue, present transcriptomes poorly represent the relevant chromatin state and expression patterns during recombination. We investigated the expression profile during early Drosophila meiosis in females, utilizing mRNA-Seq. Our analysis provides a glimpse at the most relevant patterns of expression during DSB formation and repair, and may provide insight into a complex relationship between gene expression and local recombination rates. We also note that expression patterns of nuclei from early meiotic regions of the gonad are enriched for genes involved in morphogenesis and cellular differentiation to a greater extent than the complete ovary. Additionally, we have identified more than 30 novel genes. Lastly, we detect a set of genes with a maternally derived expression pattern and find a bias towards X chromosome-expressed genes. These results indicate that the Drosophila early meiotic environment possesses a distinct pattern of expression and may reveal clues pertinent to recombination landscape patterning.