Breaking Trends: Large Animal Models to Study Spindle Assembly and Chromosome Segregation in Human Oocytes

Human oocytes are extremely prone to chromosome segregation errors. Although the mouse model has been extremely helpful in the study of oocyte meiosis, recent research has highlighted several important differences between murine and human oocytes in the mechanisms regulating spindle assembly and chromosome segregation. These limitations have led researchers to look for alternative animal models that would more closely recapitulate human meiosis. Oocytes from large animals such as cows, pigs, sheep, and horses have proved to share several features with human oocytes making them a useful addition to studies on human oocyte meiosis. In particular, the length of meiosis, the mechanisms of microtubule nucleation, the oocyte size and the aneuploidy rate in large animal oocytes closely resemble their human counterpart. Therefore, understanding the molecular mechanisms driving correct chromosome segregation in large animal oocytes can provide valuable information that can be translated to human meiosis.