The yak (Bos grunniens) is the most important livestock animal in high‐altitude regions owing to its prominent adaptability to cold conditions, nutritional deficiencies and hypoxia. The reproductive organs exhibit different histological appearances and physiological processes at different reproductive stages. Hypoxia‐inducible factor‐1 alpha (HIF‐1α) is the regulatory subunit of HIF‐1 that crucially regulates the response to hypoxia in mammalian organisms. The goal of our study was to investigate the expression and distribution of HIF‐1α in the primary yak reproductive organs at different reproductive stages. Samples of the ovary, oviduct and uterus of 15 adult female yaks were collected and used in the experiment. The expression and localization of HIF‐1α proteins and mRNA were investigated using quantitative real‐time polymerase chain reaction (qRT‐PCR), Western blot (WB) and immunohistochemistry (IHC). The results indicated that the expression of HIF‐1α protein in the ovary was higher during the luteal phase than during the follicular phase and gestation period (p < .05). In the oviduct, HIF‐1α protein was also more highly expressed during the luteal phase than during the follicular phase and gestation period (p < .01). However, in the uterus, the HIF‐1α protein had stronger expression during the gestation period than during the follicular phase (p < .01) and luteal phase (p < .05). The expression of HIF‐1α mRNA was similar to that of its protein. Immunohistochemical analysis revealed intense immunostaining of HIF‐1α proteins in the follicular granulosa cells, granular luteal cells, villous epithelial cells of the oviduct, endometrial glandular epithelium and luminal epithelium, foetal villous trophoblast, and epithelia of caruncular crypts. This study showed that the expression of HIF‐1α in the ovary, oviduct and uterus varies according to the stage of the reproductive cycle. This implies that HIF‐1α plays an important role in regulating the stage‐specific physiological function of yak reproductive organs under hypoxic environments.

中文翻译：

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缺氧诱导因子-1α在雌性牦牛(Bos grunniens)不同生殖阶段初级生殖器官中的表达。

牦牛 ( Bos grunniens) 因其对寒冷条件、营养缺乏和缺氧的显着适应性而成为高海拔地区最重要的牲畜。生殖器官在不同的生殖阶段表现出不同的组织学外观和生理过程。缺氧诱导因子-1 α (HIF-1α) 是 HIF-1 的调节亚基，它关键地调节哺乳动物生物体对缺氧的反应。我们研究的目的是调查HIF-1α在不同生殖阶段初级牦牛生殖器官中的表达和分布。采集15头成年雌性牦牛的卵巢、输卵管和子宫样品用于实验。使用定量实时聚合酶链反应 (qRT-PCR) 研究 HIF-1α 蛋白和 mRNA 的表达和定位，蛋白质印迹 (WB) 和免疫组织化学 (IHC)。结果表明，卵巢中 HIF-1α 蛋白在黄体期的表达高于卵泡期和妊娠期。p  < .05）。在输卵管中，HIF-1α 蛋白在黄体期的表达也高于卵泡期和妊娠期 ( p  < .01)。然而，在子宫内，HIF-1α 蛋白在妊娠期比卵泡期 ( p  < .01) 和黄体期 ( p < .05）。HIF-1α mRNA的表达与其蛋白相似。免疫组织化学分析显示，卵泡颗粒细胞、颗粒状黄体细胞、输卵管绒毛上皮细胞、子宫内膜腺上皮和管腔上皮、胎儿绒毛滋养层和肉状体隐窝上皮中的 HIF-1α 蛋白强烈免疫染色。本研究表明，HIF-1α在卵巢、输卵管和子宫中的表达根据生殖周期的阶段而变化。这意味着 HIF-1α 在调节缺氧环境下牦牛生殖器官的阶段特异性生理功能中起重要作用。