The mystery of how meiotic arrest is maintained in mouse oocytes is revealed this week in
Meiosis begins when oocytes are still very small cells, but it then arrests for a long period after the oocyte has reached its full size, according to co-author Laurinda A. Jaffe, and depends on signals from the follicle. In a previous study, the team had found that the heterotrimeric G protein, Gs, in the oocyte is required to maintain meiotic arrest; Gs activates adenylyl cyclase to keep cyclic AMP elevated.
Jaffe looked for the means by which Gs is stimulated. "If there's an oocyte adenylyl cyclase that...