생명과학과 신임교원 채용 후보 공개세미나

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  • 2017-01-06


생명과학과 신임교원 채용 후보 공개세미나
[Life Sciences Faculty Candidate Seminar Notice]
              ▶Subject: Meiotic recombination hotspots in Arabidopsis DNA transposons
              ▶Speaker: Kyuha Choi, Ph.D. (Gyeongsang National University)
              ▶Date: 4:00 PM/Dec. 5(Mon.)/2016
              ▶Place: Auditorium(1F), Postech Biotech Center
 Meiotic recombination and crossovers profoundly shape eukaryotic natural variation and genome evolution. Chromatin plays a major role in positioning recombination hotspots in proximity to genes, and heterochromatin can silence crossovers. However, the extent to which transposons contain or influence hotspots has remained unclear. To address this question genome-wide maps of meiotic DNA double strand breaks (DSBs) were generated by sequencing Arabidopsis SPO11-1-oligonucleotides. Arabidopsis RNA and DNA transposon families vary extensively in DSB frequency. Recombination hotspots occur inside rolling-circle Helitrons and Pogo/Tc1/Mariner cut-and-paste DNA elements, whereas RNA retroelements are coldspots. Elevated transposon meiotic DSB frequency is quantitatively driven by nucleosome occupancy and AT-sequence richness. High DSB transposons are located distally along the chromosomes, within gene promoters and terminators and significantly overlap with crossovers. Using the arp6, met1 and suvh4 suvh5 suvh6 epigenetic mutants, I also show differential remodeling of chromatin and DSBs between transposon classes, following epigenetic change. I propose that recombination hotspots within DNA transposons contribute to genetic and epigenetic variation between Arabidopsis natural populations.