Nancy M. Hollingsworth, Ph.D.

Research

Meiosis is a specialized type of cell division used by sexually reproducing organisms to produce haploid gametes from diploid cells. My lab uses a variety of approaches to understand chromosome behavior during meiosis. Our most recent work has used a chemical genetic approach to conditionally inactivate two key protein kinases, Cdc7 and Mek1, as a way of defining the roles of these kinases in meiotic recombination and cell cycle progression. Mek1 kinase activity promotes recombination between homologs during meiosis by inhibiting sister chromatid recombination. Current projects in this area involve identifying the substrates of Mek1 and elucidating the mechanism by which Mek1 is activated in response to double strand breaks (DSBs), the initiating event of recombination. Cdc7 is an evolutionarily conserved kinase best known for its role in the initiation of DNA replication in vegetative cells. Cdc7 is not, however, absolutely required for premeiotic DNA synthesis. Instead we have found that Cdc7 is necessary for a number of different meiotic processes, including the initiation of recombination, meiotic progression and the mono-orientation of sister chromatids at the first meiotic division. We are working on defining the meiotic targets of Cdc7 to determine the molecular mechanisms by which Cdc7 functions in meiosis.