UC Berkeley

Sexual reproduction relies on meiosis, a specialized cell division process that produces haploid gametes. Successful segregation of homologous chromosomes during meiosis requires the pairing of homologs, synapsis, and crossover recombination during meiotic prophase.Upon initiation of meiosis, in many organisms, chromosome ends establish connections with the nuclear envelope (NE) and interact with motor proteins that drive processive movements along the NE, facilitating homolog chromosome pairing and synapsis. In C. elegans, specialized chromosome regions known as “pairing centers” (PCs) serve this role. To understand the roles of PCs in C. elegans meiosis, I exploited a genetic screen and identified a novel protein required for homolog pairing and synapsis. Chapter 1 focuses on this newly discovered NE protein, MJL-1, which is essential for homolog pairing and the regulation of synapsis at the PCs. Chapter 2 describes my efforts to develop methodology for genome-wide profiling of chromosome-interacting proteins in the C. elegans germline, leading to new insights into chromosome organization during meiosis. Through this work, I have discovered correlations between the genome-wide distribution of chromosome axis proteins, active chromatin marks, and a protein required for meiotic double-strand breaks (DSBs), DSB-2, during meiosis in C. elegans.