The human egg—the rarest and most rapidly aging cell in the body—is a topic of intense study for scientists and in assisted reproduction (“IVF”) clinics vying for better pregnancy rates. This new edition of what one reviewer of the first edition (2003) described as, “possibly the definitive work on the oocyte,” covers the developmental biology and pathology of this mother cell, and ovotechnologies to overcome infertility, avoid inherited diseases, and create genetically engineered embryos from stem cells and cloning. The book is thoroughly updated with many new revealing a cell that is nudging towards a role at the center stage of contemporary biomedicine.