Infertility, spontaneous abortion and genetic disease risk are closely related with oocyte quality. While the ARTs have brought babies for millions of infertile couples, the success rate is still low. More evidence shows that embryo quality is mainly determined by oocyte. After birth, oocytes in mammalian ovaries are arrested at prophase of first meiosis, manifested by the germinal vesicle (GV) located at the center of the oocyte. Oocyte maturation, the final step of oogenesis, begins with the germinal vesicle breakdown (GVBD) and ends with the first polar body emission, awaiting fertilization. During the program of oocyte maturation, two important processes must take place. First, during meiosis I, homologous chromosomes segregate, followed by second meiosis that takes place after fertilization, to ensure haploid gamete production. Second, the two meiotic divisions must occur asymmetrically to maintain almost all the cytoplasm in the egg to support early embryogenesis. Meiotic errors do occur, especially as women get older. Our research focuses on female meiosis where we use oocyte specific conditional knockout and imaging based techniques to explore the regulation of this process. We are interested in how the two meiotic divisions are controlled at a molecular level. In addition we also use several reproduction-related animals models (diabetes, obesity, PCOS, insulin-resistence etc) and clinical materials to study factors affecting oocyte quality which affects fertilization and embryo development.
