YAP1 Is Associated with Cumulus Expansion-Related Factor Expression and Autophagy-Related Signaling in Yak Cumulus Cells.

Cumulus expansion is important for oocyte maturation, but its molecular regulation in yak remains unclear. This study examined the association of Yes-associated protein 1 (YAP1) with cumulus expansion-related and autophagy-related molecular markers in cumulus cells isolated from yak cumulus-oocyte complexes collected from ovarian follicles. YAP1 was overexpressed or knocked down, and YAP1-overexpressing cultures were additionally treated with 3-methyladenine (3-MA). Transcript abundance was assessed by RT-qPCR and interpreted descriptively, whereas protein abundance was evaluated by Western blotting; representative immunofluorescence and mCherry-GFP-LC3B images were also examined. YAP1 overexpression significantly increased HAS2 and PTGS2 protein abundance, while PTX3 and TNFAIP6 showed non-significant upward trends; YAP1 knockdown significantly reduced all four proteins. YAP1 manipulation was also associated with changes in Beclin-1, ATG5, p62, and the LC3B-II/LC3B-I ratio. Compared with YAP1 overexpression alone, 3-MA co-treatment significantly reduced HAS2, PTGS2, PTX3, TNFAIP6, Beclin-1, and ATG5, increased p62, and numerically reduced the LC3B-II/LC3B-I ratio without statistical significance. These findings support an association between YAP1 and cumulus expansion-related molecular programs and are consistent with partial involvement of 3-MA-sensitive, autophagy-associated signaling. Direct functional assays and pathway-specific validation are required to establish causality.