Functional Genomic Screen (Fgs) To Identify Host Genes Required For Retrotransposition In S.Pombe Genome
Friday, September 18, 2015 — Poster Session V
- Henry Levin
Unique integration patterns of Long Terminal Repeat (LTR)-retrotransposons and the use of retroviruses in gene therapy have generated great interest in target-site selection. Initially, the RNA transcripts of the retroviruses and retrovirus-like elements are reverse transcribed into full-length cDNA copies that are subsequently inserted into the host cell genome. Although integrase, encoded by retroviruses and retrotransposons, is responsible for catalyzing the insertion of cDNA into the host genome, it is now clear that a variety of host factors are required for targeting and selection of the integration sites. To understand how retroviruses and retrotransposons position their sites of integration at specific locations in the host genome, we study the LTR-retrotransposon Tf1 of Schizosaccharomyces pombe. A genetic assay that measures cDNA present in the nucleus allows us to determine whether mutations that reduce transposition frequencies have a direct impact on the process of integration. We utilized this genetic assay to screen a collection of 3,004 S. pombe deletion strains for defects in integration. We found that 177 deletion strains have reduced transposition and 98 of these likely have specific defects in integration. Candidates that may contribute to integration include factors responsible for DNA repair, transcription activation, signal transduction, and nucleosome structure.