This program area, directed by Dr. Susan Taymans, supports research on the genetic and epigenetic components of reproduction, with special emphasis on identifying genes important for reproductive success and mutations that compromise fertility. This program's efforts also include research to identify genetic networks and their mechanisms of action that influence the development of the gonads, reproductive ducts, and genitalia; the processes of gametogenesis; normal and premature reproductive aging; and reproductive disorders such as infertility, cryptorchidism, and polycystic ovarian syndrome. A goal of this program is to identify candidate genes for human disorders of reproduction through the support of large population-based studies, as well as through gene profiling studies that compare pathological and normal tissues. Emphasis is also placed on supporting the development of animal models to study the contribution of genetics to human fertility disorders, and to identify leads for novel contraceptive approaches. This program also includes research into epigenetic mechanisms that are critical to reproduction, including the timing, mechanisms, and role of genomic methylation in gametogenesis; the effects of assisted reproductive techniques on imprinting and genomic methylation in gametes; and the reproductive determinants and consequences of X-chromosome inactivation.