Young retrogene detection in Drosophila. Tatiana A. Gurbich¹, JJ Emerson², Doris Bachtrog¹. 1) Integrative Biology, University of California, Berkeley, Berkeley, CA; 2) Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA.

   Retroposed genes are duplications that originate when mature mRNA of the parental gene is reverse transcribed and inserted in a new location in the genome. Because of the nature of this mechanism, retroposition is not only a source of novel genes, but is also a tool by which genes can change their genomic location. Studying young retrogenes can provide insight into selective forces that shape chromosome content. Detecting young retrogenes in assembled genomes can be problematic due to low divergence of exonic sequence between the parental gene and the retrocopy, which can lead to the retrocopy not being assembled at all. Retrogenes are also likely to be surrounded by repetitive DNA sequence which results in these regions often being unassembled. These properties of young retrogenes can lead to them being undetected in analysis. In this study, we implemented a suite of methods that can be used to detect retrogenes from raw sequencing data without relying on an assembled genome. We show that with our methodology we can detect more retrogenes than was possible previously. We also present data on young retropositions in Drosophila miranda that originated since D.miranda's split from Drosophila pseudoobscura ~1.5 million years ago.