Mechanisms directing homolog bi-orientation during meiosis I. (360G-Wellcome-089399_Z_09_Z)

Erroneous chromosome segregation in me1os1s results in gametes carrying an incorrect number of chromosomes. This can cause infertility, miscarriages, and birth defects such as Down's syndrome. To understand how these arise, a better understanding of how chromosomes are segregated is needed. Unique to meiosis is the segregation of maternal and paternal chromosomes or homologs towards opposite spindle poles. However, how homolog bi-orientation is achieved is unknown. The main goal of my study will be to elucidate the mechanism by which homologous chromosomes obtain bi-orientation during meiosis I. For this study I will use budding yeast, because its meiosis is relatively simple yet conserved. Specifically, the aims of my study are: 1) Establish the role of two kinetochore proteins Ctf19 and Mcm21 in ensuring proper segregation of homologous chromosomes during meiosis. 2) Identify proteins involved in homolog bi-orientation and determine their mechanism of action.