MANIPULATION OF OOCYTE MATURATION IN-VITRO

The growing follicle holds the oocyte in meiotic arrest In the mouse, follicular fluid appears to act through modulation of cAMP levels with in the oocyte to suppress maturation, but in cattle and horses, the me chanism for meiotic arrest is still unclear. Maintenance of meiotic ar rest in bovine and equine oocytes by follicular components in vitro re quires exposure to granulosa cells. Further work is needed to isolate and characterize the active factor produced by granulosa cells, and it s mechanism of action. Resumption of meiosis in bovine and equine oocy tes requires synthesis of new proteins, and in equine oocytes, the per iod of protein synthesis required varies according to the follicular o rigin of the oocyte (atretic vs. viable).