FIG. 7.

Model of major amino acid transport systems in growing and maturing mouse oocytes. A) Major transport systems detected in growing oocytes (left). The effect of the presence of follicle cells on the transport of model substrates (right) for these systems into growing oocytes is indicated by the text size, with smaller text indicating that follicle cells decreased uptake and larger text indicating that follicle cells increased uptake. B) Major transport systems in oocytes during meiotic maturation. Systems detected in growing oocytes remained present through meiosis (left), while three systems whose activity was low or absent during oocyte growth became activated during maturation (right). In both A and B, transport systems with low or uncertain activity (e.g., GLY and β during oocyte growth and N) are not shown.