为了研究人类近亲恒河猴中PIWI家族蛋白PIWIL4的结构和表达情况, 文章首次利用同源比对和RT-PCR方法克隆了恒河猴piwil4基因, 检测了其mRNA在恒河猴心脏、脑、结肠、附睾和睾丸5种组织中的表达情况, 利用生物信息学的方法对恒河猴piwil4基因和人的PIWIL4 (HIWI2)基因编码的蛋白产物进行了同源性分析和结构域分析, 并进一步利用免疫组化的方法比较了PIWIL4蛋白在成人、成年恒河猴和性未成熟恒河猴睾丸组织中的表达分布。结果表明, 恒河猴piwil4 mRNA在多组织中表达, 恒河猴和人的PIWIL4蛋白的氨基酸序列同源性达97%以上, 均含有PAZ和Piwi结构域, 它们在两物种成年个体睾丸组织中空间分布一致, 但在不同发育阶段恒河猴睾丸组织中的分布发生了改变, 幼猴中PIWIL4蛋白主要表达于生精小管细胞的细胞核, 在成年猴睾丸组织中则表达于各种细胞的胞浆中。上述结果提示, piwil4基因在人类和恒河猴精子发生过程中作用类似, PIWIL4蛋白在幼猴和成年猴睾丸组织中的表达差异提示它们在不同发育阶段功能的改变。
To investigate the structure and expression pattern of rhesus monkey PIWIL4 protein, homologous comparison and reverse transcription PCR (RT-PCR) were carried out to identify rhesus monkey piwil4. The expression of piwil4 mRNA was tested in rhesus monkey heart, brain, colon, epididymis and testis, and the result showed that piwil4 mRNA was expressed in these rhesus monkey tissues. Bioinformatic analysis suggested that the rhesus PIWIL4 protein shared 97% identity in amino acids and the same domains such as PAZ and Piwi with the human PIWIL4 (HIWI2) protein. The immunohistochemical result indicated that PIWIL4 proteins had the same localization in adult testes of the two species, but the distribution of these proteins was altered dynamically at different developmental stages in rhesus monkey testes. PIWIL4 protein was expressed in the nucleus of convoluted seminiferous tubules in infant monkey testes, whereas it was expressed in the cytoplasm of adult monkey testes. The results suggest that piwil4 gene play a similar role in rhesus and human, and different localizations of PIWIL4 protein in infant monkey and adult monkey testes suggest that it functions differently at different developmental stages.
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