Infertility is a major problem that affects domestic mammals and declining fertility represents an obstacle in maintaining profitability of dairy farms in Europe and worldwide. Since declining fertility of cattle is mainly due to the poor quality of the oocytes, defining the factors and mechanisms that affect oocyte quality, is essential for improving female fertility. In particular, basic knowledge of which proteins within the oocyte regulate meiosis, oocyte fertilizability and early embryonic development would be advantageous. Based on our preliminary data, we propose that Progesterone Receptor Membrane Component 1 (PGRMC1) is one of the key factors that regulate mammalian oocyte quality. This hypothesis will be rigorously tested by determining 1) whether PGRMC1 plays an essential role in maintaining the ability of bovine oocytes to complete meiosis, undergo fertilization and develop to an healthy embryo in vitro, by genetically manipulating the levels of PGRMC1 within the oocyte, and 2) PGRMC1s mechanism of action by identifying its interacting proteins within the oocyte. The scientific program is directly linked to the studies that the candidate has conducted during her period of mobility at the University of Connecticut Health Centre (USA) and should result in important discoveries in the field of reproductive biology. If granted, this study will contribute to the improvement of the quality of European research and will improve significantly the lifelong training and career development of the applicant, providing the opportunity to capitalize in Italy on her experience on this promising topic.