The expression of follicle-stimulating hormone receptor and luteinizing hormone receptor mRNA in prehierarchical and preovulatory follicular granulosa cells by reverse transcription polymerase chain reaction. 1DL2000 marker; 2, 3polymerase chain reaction products of beta-actin in prehierarchical follicles of the control and experimental group; 4, 5polymerase chain reaction products of the follicle-stimulating hormone receptor in prehierarchical follicles of the control and experimental group; 6, 7polymerase chain reaction products of the luteinizing hormone receptor in prehierarchical follicles of the control and experimental group; 8, 9polymerase chain reaction products of beta-actin in preovulatory follicles of the control and experimental group; 10, 11polymerase chain reaction products of the follicle-stimulating hormone receptor in preovulatory follicles of the control and experimental group; 12, 13polymerase chain reaction products of the luteinizing hormone receptor in preovulatory follicles of the control and experimental group.