Ovulation Signals

摘要

Successful mammalian reproduction requires that the female gamete (oocyte or egg) acquires, within the growing ovarian follicle, the ability to be fertilized. Failure to initiate or complete follicle development, or defects in the oocyte (such as aneu-ploidy) result in infertility. On page 938 in this issue, Fan et al. describe cellular signaling pathways in the mouse ovary that support follicle maturation and, ultimately, the discharge of a mature egg. The findings could help elucidate the underlying molecular nature of ovarian pathology and infertility-producing conditions in humans.rnIn the mammalian ovary, a specific number of follicles (for example, usually one in humans and up to 10 in mice) ovulate during each reproductive cycle. Follicle development and ovulation are controlled by two pituitary hormones, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) (see the figure). Luteinizing hormone causes an orderly continuum of follicle remodeling, which includes expansion in overall size (through fluid uptake), and termination of cell division in granulosa cells, the somatic cells in the ovary that support the oocyte.