Focus

Research in our laboratory focuses on mammalian germ cell development with the aim of increasing our understanding of the genetic control of sex determination and of the meiotic process in mammals. Our research involves studies of both humans and mice.

We are conducting studies of human oocytes in association with the Department of Reproductive Biology at University Hospitals. The aim of this research is to elucidate the basis of the maternal age effect in the human female; that is, to determine why, as women age, they are at an increased risk of producing chromosomally abnormal children. Although we know that the maternal age effect is the result of meiotic errors in the egg and that most errors occur during the completion of the first meiotic division (around the time of ovulation), the mechanism by which age increases the frequency of errors remains unknown. Recent studies in our laboratory suggest that, with increasing age, the growth process of the human oocyte may become perturbed (Volarcik et al., 1998). Hence one goal of our research is to understand how changes in the environment in which the oocyte undergoes its final growth and maturation effect the meiotic process.

In addition, we are studying a number of different mouse mutants to understand the genetic control of the meiotic cell cycle in mammals and the factors that influence meiotic chromosome alignment and segregation. These studies make use of new techniques for the in vitro growth of murine follicles, the production of chimeric ovaries, the analysis of meiotic cell cycle progression and the analysis of meiotic chromosome behavior. Our recent studies suggest that the control of mammalian female meiosis differs in fundamental respects from both male meiosis and mitosis and that these differences may provide a key to understanding the high error rate in female meiosis (LeMaire-Adkins et al., 1997).