[Expression and localization of Uhrf1 in the major reproductive organs of yaks during different reproductive cycles]

Uhrf1 is a multi-domain and multifunctional epigenetic regulator playing key roles in DNA methylation, cell metabolism, and cell proliferation. To investigate the role of Uhrf1 in the reproductive physiology of female yaks, we collected three reproductive organs (ovaries, oviducts, and uteri) from healthy yaks during three reproductive phases (follicular, luteal, and gestational phases), with a total of nine groups. Real-time fluorescence quantitative PCR (RT-qPCR), Western blotting, and immunohistochemistry (IHC) were employed to determine the expression levels of Uhrf1 and the subcellular localization of this protein. RT-qPCR and Western blotting results showed that Uhrf1 was expressed highest in the oviduct during the follicular phase, moderate expression in the uterus during the gestational phase, and the lowest expression in the uterus during the luteal phase (P < 0.05). IHC results showed that Uhrf1 was mainly expressed in the ovarian germinal epithelium, theca follicular, follicular granulosa, luteal cells, oviduct mucosal epithelial cells, and uterine glands (UG) of yaks. In conclusion, Uhrf1 was differentially expressed in the major reproductive organs during the reproductive cycle of female yaks, indicating its important regulatory role in the reproductive physiology of yaks.