High throughput genetic screening of higher crossover rate mutants in Arabidopsis

Abstract

Meiotic homologous recombination generates crossovers from programmed DSBs via interhomolog repair pathways. The meiotic crossover frequency and distribution affect genetic diversity in population and breeding. Crossover number is restricted to ~1-3 along a chromosome by anti-crossover factors including FANCM, RECQ4 and FIGL1 in Arabidopsis. However, the mechanism how the excessive DSBs (~40-50 per chromosome) are repaired to only 1-3 crossovers remains further elucidated. We performed a high throughput genetic screening of higher crossover rate (hcr) mutants by using fluorescent seed-based system, enabling the measurement of crossover frequency in individual plants from EMS-driven mutant pool. We have isolated three hcr mutants (hcr1, hcr2, hcr3) that were confirmed to be new anticrossover mutants by genetic analysis and deep-sequencing. In this poster we will present characterization of hcr2 and hcr3 mutants, including mapping of them and their effects on crossover frequency.