My lab studies the regulation and execution of meiotic recombination using the budding yeast, Saccharomyces cerevisiae. Meiosis is the specialized cell division that divides the chromosome number in half to make haploid gametes for sexual reproduction. During meiosis, replicated chromosomes undergo two divisions: at Meiosis I, homologous chromosomes segregate to opposite poles of the spindle, while sister chromatids segregate at Meiosis II. Meiosis is a highly conserved process and many of the genes necessary for meiosis in yeast are also required for mammalian meiosis. My lab uses genetic, molecular biological, biochemical and cytological approaches to identify and characterize genes important in meiosis.

Meiotic recombination creates crossovers between homologous chromosomes that, in combination with sister chromatid cohesion, allow the pairs of homologs to segregate properly at the first meiotic division. Meiotic recombination is initiated by the introduction of programmed double strand breaks that are then processed to produce either crossover or noncrossover chromosomes. The repair of these double strand breaks is regulated. The major questions that my lab is currently trying to answer are:

1. What are the roles that the conserved Sen1 DNA/RNA helicase plays during premeiotic S phase and meiotic recombination? Sen1 can disassemble DNA/RNA hybrids that form either during premeiotic S phase or on the resected ends of meiotic double strand breaks.

1. The successful completion of interhomolog recombination during prophase I of meiosis results in the formation of a structure that connects pairs of homologous chromosomes called the synaptonemal complex. Any remaining double strand breaks must be then be repaired before chromosomes segregate at the first meiotic division. My lab is interested in identifying the genes that mediate this repair and the mechanisms by which this repair occurs.