Heat shock protein 70 (HSP70) has been widely reported to play a vital role in maintaining intracellular homeostasis, mainly through cellular protection and immune regulation. The expression and function of HSP70 can vary depending upon species and age. To explore the expression signatures and regulatory functions of HSP70 in the reproductive organs of male sheep, we evaluated the expression and distribution patterns of HSP70 in the testes and epididymides (caput, corpus, and cauda) of Tibetan sheep at three developmental stages (i.e., 3 months, 1 year and 3 years after birth) by qRT-PCR, Western blot and immunofluorescence. HSP70 was found to be expressed in testes, caput, corpus, and cauda epididymides throughout the developmental stages but is mainly expressed postpuberty (1 year and 3 years old). Immunofluorescence results revealed that in the testes, a positive reaction for HSP70 protein was mainly seen in round spermatids and luminal sperms from the groups aged 1 year and 3 years. In caput epididymides, the positive signals for HSP70 protein was notably observed in sperm and principal cells of the epididymal epithelium from the groups aged 1 year and 3 years, and positive signals in the epididymal interstitium were found in all three age groups. In corpus and cauda epididymides, HSP70 protein was present in the epididymal epithelium and interstitium, and the positive signals gradually increased with age. In conclusion, these findings suggest that Tibetan sheep HSP70 may play a crucial role in further development and maturation of postmeiotic germ cells and participate in regulation of intraepididymal homeostasis maintenance in Tibetan sheep.

据报道，热休克蛋白70（HSP70）主要通过细胞保护和免疫调节在维持细胞内稳态中起着至关重要的作用。HSP70的表达和功能可以根据物种和年龄而变化。为了探索HSP70在雄性绵羊生殖器官中的表达特征和调控功能，我们评估了HSP70的表达和分布方式通过qRT-PCR，Western印迹和免疫荧光法检测藏羊在三个发育阶段（即出生后3个月，1年和3年）的睾丸和附睾（cap 、,体和马尾）。发现HSP70在整个发育阶段均在睾丸、,、,体和附睾中表达，但主要在青春期后（1岁和3岁）表达。免疫荧光结果显示，在睾丸中，HSP70蛋白的阳性反应主要出现在1岁和3岁年龄组的圆形精子和管腔精子中。在附睾附睾中，在1岁和3岁组的附睾上皮的精子和主要细胞中，HSP70蛋白的阳性信号显着，而在所有三个年龄组的附睾间质中均发现了HSP70蛋白的阳性信号。在体和马尾附睾中，HSP70蛋白存在于附睾上皮和间质中，并且阳性信号随年龄逐渐增加。总之，这些发现表明藏族绵羊HSP70可能在减数分裂后生殖细胞的进一步发育和成熟中发挥关键作用，并参与调节藏绵羊的表皮内稳态维持。