Isolation of yeast genes that suppress the chromosome loss defect of 'YAC stability in mitosis' mutants.

The eukaryotic cell cycle and processes that maintain genome stability occur with high fidelity. Mutations in genes important for the structure, replication, repair, and/or segregation of chromosomes are correlated with genome instability (i.e., chromosome rearrangements, increased mutation rates, aneuploidy, abnormal chromatin structure, and/or abnormal gene expression). As part of an effort to identify proteins important for genome stability, we previously implemented a genetic screen in the yeast Saccharomyces cervisiae that allows for visual detection of mutants with increased loss of an ADE2-marked yeast artificial chromosome (YAC). This screen resulted in 132 –AC stability in mitosis (ysm) mutants. Three mutants, ysm76, ysm83, and ysm84, have been further characterized for phenotypes related to genome instability. In addition, both high copy and single copy suppressors of these mutants’ YAC loss defects are being isolated. Identification of these suppressors will contribute to our understanding of protein networks and processes important for eukaryotic genome stability