Life Sciences Café

"The evolution of genome structure in Drosophila," presented by J.J. Emerson, Asst. Professor, University of California Irvine.

Abstract: 
Mutations that shape the structure of genome sequences often affect the phenotypes of the organisms in which they occur. These changes include mutations that copy or delete genes, rearrange gene order, or insert mobile elements into the regions that control gene expression. However, many of these changes remain difficult to identify with so-called next generation sequencing. Paradoxically, as sequencing DNA has become easier, the primary tools for understanding genome sequences — reference genomes — have become more fragmented and less complete on average, sharply limiting what we can learn about genome variation.

Recent advances in sequencing now permit researchers to paint a nearly complete picture of the structure of multiple genomes. J.J. Emerson applies these techniques to uncovering genetic variation that exists within and between species of Drosophila. He finds that more of the genome is affected by structural variants (SVs) invisible to short read sequencing than is affected by single nucleotide polymorphisms and small insertion/deletion mutations combined. Surprisingly, many of these SVs are strong candidates for mutations causing variation in complex traits.

Emerson describes three structural variants, including two associated with resistance to nicotine and one associated with temperature preference in Drosophila melanogaster. He closes with current progress in the complete sequencing of populations within and between Drosophila species.

Light refreshments will be served.