Research Summary

Genetic analysis of crossover assurance mechanisms facilitating meiotic chromosome segregation

Crossovers are essential for chromosome segregation during meiosis. In the baker's yeast Saccharomyces cerevisiae and mammals, meiotic crossing over is controlled by a subset of the mismatch repair related factors, MSH4-MSH5 and MLH1-MLH3. Research in my laboratory is focused on understanding how crossover number and placement on homolog pairs are regulated to ensure segregation. We make use of a sensitized system involving S. cerevisiae msh4/5 mutants that can segregate chromosomes with a twofold reduction in crossovers to ask: What are the preferred chromosomal locations where occurrence of a crossover event assures segregation of the homolog pair? What genes products are required to maintain crossover assurance on all homolog pairs? These studies will provide us new insights into crossover assurance mechanisms that prevent aneuploidy in gametes.