2003 Fiscal Year Final Research Report Summary

Homing directed by VDE endonuclease in Saccharomyces cerevisiae

Research Project

Project/Area Number	10216203
Research Category	Grant-in-Aid for Scientific Research on Priority Areas
Allocation Type	Single-year Grants
Review Section	Biological Sciences
Research Institution	The University of Tokyo
Principal Investigator	OHYA Yoshikazu The University of Tokyo, Graduate School of Drontier Sciences, Professor, 大学院・新領域創成科学研究科, 教授 (20183767)
Project Period (FY)	1998 – 2002
Keywords	VDE / Saccharomyces cerecvisiae / Non-homologous end joining / DNA repair
Research Abstract	In Saccharomyces cerevisiae, DNA double strand breaks (DSBs) are repaired by several mechanisms. Non-homologous end joining (NHEJ) efficiency is down-regulated in diploid cells relative to haploid cells at mitosis, but the mechanism of this mating type regulation at meiosis is unknown. When DSBs occur without homologous, template at meiosis, a few spores survive. In survival spores, DSBs might be repaired by NHEJ. To test this idea, we introduced DSB specifically in mieiosis by VDE endonuclease. and examined spore viability in the wild-type, nejl Δ and yku70Δ strains. The spore viability of these deletion mutants reduced in comparison with wild type. The viable spores contain short insertions or deletions typical for DNA repair caused by NHEL. The results suggest that DSBs is repaired by NHEJ in survival spores and DSBs repair by NHEJ occurs at meiosis.