摘要： 旨在克隆牦牛水通道蛋白2基因（Aquaporin 2，AQP2），并检测其在牦牛不同组织及其雄性生殖道发育过程中的表达模式，为探索AQP2在牦牛雄性生殖中的作用机制提供可靠数据。以牦牛为研究对象，利用RT-PCR技术获取牦牛AQP2 cDNA序列，使用生物信息学软件分析其功能和结构。利用实时荧光定量PCR（Quantitative Real-time PCR，qRT-PCR）检测AQP2在牦牛肾、睾丸、附睾、脾脏、脑、肺脏、心脏和肝脏组织中的表达模式以及不同发育时期雄性生殖道中的表达规律。结果显示，得到AQP2基因CDS序列，长816 bp，共编码271个氨基酸，并发现牦牛AQP2基因与黄牛、水牛和山羊的同源性较高，AQP2在睾丸和肾中高表达，显著高于其他组织（P<0.05）。免疫组化结果发现，AQP2仅在曲细精管的圆形精子细胞中表达，而精原细胞、精母细胞、长形精子细胞、间质细胞及支持细胞均未见其表达。qRT-PCR结果显示，在牦牛雄性生殖道中，输精管中的AQP2表达量最高（P<0.05），且AQP2 mRNA在睾丸和输精管中的表达水平随年龄增长逐渐升高（P<0.05），而在前列腺中其表达水平随年龄增加稍有降低，但差异不显著（P>0.05）。以上结果表明，AQP2在遗传进化上高度保守，在睾丸和肾组织中高表达，参与精子成熟及运输过程，可能是通过调节水重吸收和液体形成来完成。

关键词: 牦牛, AQP2, 睾丸, 组织表达

Abstract: The aim of this research was to clone the aquaporin 2 (AQP2) gene, identify its expression pattern in various tissues, and to analyze the expression in different growth periods of the male reproductive system in yak.This research may provide important foundation for exploration the role of AQP2 for reproductive development in yak.The samples of yak kidney, testis, epididymis, spleen, brain, lung, heart and liver were collected after slaughtering. The total RNA of different samples were extracted and the coding sequence of AQP2 gene was cloned by RT-PCR. Meanwhile the function and structure of AQP2 gene were analyzed by bioinformatics softwares.Then, the mRNA expression of AQP2 in different tissues and in different growth periods of the male reproductive system was detected by quantitative real-time PCR (qRT-PCR). The results showed that the CDS region of AQP2 gene was 816 bp, encoding 271 amino acids. It had high homology with cattle, buffalo and goat. The tissues expression analysis showed that AQP2 highly expressed in testis and kidney, which was significantly higher than other tissues (P<0.05). The results of immunohistochemistry indicated that AQP2 was expressed in round spermatids of seminiferous tubules, but no expression was found in spermatogonia, spermatocytes, elongated spermatids, leydig cells and sertoli cells. The results of qRT-PCR was found that the expression of AQP2 in vas deferens was the highest(P<0.05). The expression trend of AQP2 mRNA in testis and vas deferens was increased with age (P<0.05). While the expression level in prostate was slightly decreased with age, but the difference was not significant(P>0.05). The above results indicated that AQP2 was highly conserved during evolution, and it was highly expressed in testis and kidney. It was involved in sperm maturation and transportation, which might be completed by water reabsorption and liquid formation.

Key words: Yak, AQP2, Testis, Tissue expression

中图分类号: 

• Q78

• S823