Interpretive Summary: Wingless-type mouse mammary tumor virus integration site regulation of bovine theca cells

By: Anne Kamiya, MS

Wingless-type mouse mammary tumor virus integration site (WNT) signaling molecules are intraovarian factors that may influence follicular maturation and development. It is hypothesized that WNT ligands and frizzled family members (FZD) impact ovarian paracrine function and mammalian follicular development. However, research verifying these hypotheses are lacking, particularly in cattle. 

In this recent Journal of Animal Science study, an attempt was made to elucidate the role of the WNT system in cattle reproduction. It was hypothesized that WNT family members were involved in bovine ovarian function via regulation of theca cells (TC). 

Large and small bovine ovarian TC were treated with WNT family member 3A and 5A (WNT3A, WNT5A), R-Spondin-1 (RSPO1), Dickkopf-1 (DKK1), insulin-like growth factor-1 (IGF1), bone morphogenetic protein-7 (BMP7), Indian hedgehog (IHH) protein, ovine luteinizing hormone (LH) or fibroblast growth factor-9 (FGF9). Theca cells were then evaluated for proliferation and steroidogenesis. Results supported the authors’ hypothesis, finding TC were indeed regulated by the WNT system. Overall, the results of this study provide useful data which may serve as a bridge to better understanding the WNT system and how it influences reproductive health and efficiency in cattle. However, more in-depth studies are needed to better elucidate the complex interactions of the WNT system in ovarian paracrine regulation. 

The original article, Wingless-type mouse mammary tumor virus integration site regulation of bovine theca cells, is viewable in the Journal of Animal Science.