Regulation of the Activin-Inhibin-Follistatin System by Bone Morphogenetic Proteins in the Zebrafish Ovary.

Regulation of the Activin-Inhibin-Follistatin System by Bone Morphogenetic Proteins in the Zebrafish Ovary.
Biol Reprod. 2013 Jul 10;
Authors: Li CW, Ge W
Abstract
In the zebrafish, the dynamic expression of the activin-inhibin-follistatin system during folliculogenesis and its exclusive localization (except follistatin) in the follicle cells suggest that the system plays important roles in follicle development and its expression is subject to tight controls, probably by external factors including those derived from the oocyte. We have previously identified zebrafish bone morphogenetic proteins (BMPs) as oocyte factors that may act on the follicle cells; however, the targets of BMPs in the follicle cells remain unknown. Considering their spatiotemporal expression in the follicle, we hypothesized that members of the activin-inhibin-follistatin system in the follicle cells could be potential target genes of BMPs. In the present study, we developed a novel co-culture system to co-incubate zfBMP2b/4-producing CHO cells with zebrafish follicle cells. During incubation, the zfBMPs secreted from the CHO cells would act directly on the follicle cells in a paracrine manner. Our results showed that all activin beta subunits (inhbaa, inhbab and inhbb) were down-regulated by both zfBMP2b and zfBMP4, while follistatin (fst, activin-binding protein) and inhibin alpha (inha, activin antagonist) were significantly up-regulated. The specificity of BMP actions ...

Source: Biology of Reproduction - July 10, 2013 Category: Reproduction Medicine Authors: Li CW, Ge W Tags: Biol Reprod Source Type: research