Hormonal regulation of expression of @entity48835 receptor type I and II genes in the XXXX ovarian follicle.

@entity71968 @entity41030 @entity53 @entity48835 @entity291
@entity48835 ( @entity48835 ) and bone morphogenetic proteins (BMPs) are crucial factors in follicular growth and development. @entity48835 and BMPs initiate signaling by assembling type I (ALK-3, ALK-5 and @entity41030 ) and type II ( @entity71968 ) receptors. However, the mechanism regulating the expression of these receptors in the process of @entity291 follicle development is still unknown. The aim of the present study was to clarify the involvement of receptor systems for @entity48835 and BMPs in follicular selection by examining the effects of FSH and @entity53 -17beta (E2) on the regulation of @entity71968 , ALK-3, ALK-5 and @entity41030 mRNA expression in @entity291 granulosa cells (GCs). To observe mRNA expression during follicular development, follicles were obtained from heifers and classified into two groups: pre-selection follicles (PRFs) (an average of 7.7 mm follicles with low E2) and post-selection follicles (POFs) (an average of 15 mm follicles with high E2). Theca layer cells (TCs) and GCs were harvested from aspirated follicles. For in vitro studies, GCs were obtained from @entity291 follicles of 4-7 mm diameter and cultured in Dulbecco's modified Eagle's/F12 (DMEM/F-12) medium with 10% fetal calf serum for 24 h. The medium was then replaced with serum-free DMEM/F-12 supplemented with different doses of E2 (1, 10, 100 ng/ml) or FSH (1, 5, 10 ng/ml) or combinations of 1 ng/ml of E2 with different FSH doses. Total RNA was extracted and the mRNA expression of @entity71968 , ALK-3, ALK-5 and @entity41030 was estimated by the quantitative real-time PCR method using a LightCycler. @entity71968 and ALK-5 expression was significantly higher in the GCs of POFs than in those of PRFs, whereas ALK-3 expression was significantly lower in the GCs of POFs than in those of PRFs. There was no difference in @entity41030 expression in GCs between PRFs and POFs. The expression of @entity71968 , ALK-5, ALK-3 and @entity41030 genes in the TCs was not significantly different between PRFs and POFs. Treatment of GCs with E2 alone increased @entity71968 mRNA expression at a concentration of 100 ng/ml and ALK-5 mRNA expression at 10 ng/ml. @entity71968 and ALK-5 mRNA levels were up-regulated by the combination of E2 (1 ng/ml) and FSH (5 ng/ml). On the other hand, FSH alone down-regulated the expression of @entity71968 and ALK-5 in GCs. The results of the present study provide the first evidence that FSH and E2 regulate the expression of @entity71968 and ALK-5 genes in @entity291 GCs. Thus, our data suggest that the @entity48835 / @entity71968 /ALK-5 system may be critically involved in the process of selection of @entity291 follicles.
