Ovulation
Control
In mammals, the ability of a female to remain fertile depends on the continuous
activation of oocyte-containing follicles from their
dormant state in the ovary. Menopause, or the natural end of the female
reproductive cycle, occurs when the primordial follicle pool has been
exhausted. However, the molecular mechanisms underlying follicle activation
have been poorly understood. Now, in a report that Pten, a
gene best known for its role as a tumor suppressor, plays a vital role in
regulating this process. The researchers showed that in genetically
engineered mice lacking PTEN in their oocytes, the
entire pool of immature eggs is activated prematurely, depleting the supply of
mature, fertilizable eggs by early adulthood -- a situation similar to that of
premature ovarian failure in humans. As noted by J. Marx, whether mutations in
PTEN or in other proteins that cooperate with PTEN are involved in human
ovarian problems remains to be determined. If so, the new findings may aid the
design of improved fertility treatments.
Click on following links to
read related articles