UC Berkeley

Meiosis is the specialized cell division by which haploid egg and sperm cells are generated from mitotically dividing diploid germ cells. During early prophase, the environment of the nucleus is dynamic, as a given chromosome will undergo a series of encounters with homologous and nonhomologous chromosomes. A fundamental problem is how each chromosome is able to discriminate and accurately pair and form stabilized interactions via the synaptonemal complex only with its appropriate partner. It is only within this context of homologous interactions that recombination can take place, which is what allows for genetic diversity among sexually reproducing species.

In Chapters 1 and 2, I will focus on homolog pairing and synapsis and will discuss experiments that point towards the Pairing Center protein HIM-8 functioning as a molecular link that couples these two events. In Chapter 3, I will discuss the role of the chromatin factor GAK-1 in meiosis. I will show that GAK-1 plays a role at multiple steps in meiosis, including recombination and maintenance of the synaptonemal complex. The data suggest that GAK-1 may function as a transcription factor for meiosis-specific genes, which would explain the pleiotropic effects seen in meiosis. These studies will hopefully further our understanding of the molecular basis of aneuploidies.