Takahashi Tohru, Tanaka Hiromitsu, Iguchi Naoko, Kitamura Kouichi, Chen Yily, Maekawa Mamiko, Nishimura Hiromi, Ohta Hiroshi, Miyagawa Yasushi, Matsumiya Kiyomi, Okuyama Akihiko, Nishimune Yoshitake
Department of Science for Laboratory Animal Experimentation, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan.
Biol Reprod. 2004 May;70(5):1485-92. doi: 10.1095/biolreprod.103.026096. Epub 2004 Jan 14.
Mammalian spermiogenesis is a complex process occurring in a highly coordinated fashion within the seminiferous tubules. To elucidate the molecular mechanisms controlling haploid germ cell differentiation, we have isolated haploid germ cell- specific cDNA clones from a subtracted cDNA library of mouse testis. One of these cDNAs, Rosbin, is 3.2 kilobases (kb) long and has an open reading frame of 2385 nucleotides encoding a putative protein of 795 amino acid residues. A computer-mediated homology search revealed that it contained a domain similar to that of homeobox genes. Northern blot analysis revealed a 3.2-kb mRNA expressed exclusively in male germ cells. Transcription of the Rosbin gene was not observed in prepubertal testis but became detectable after Day 23. By Western blot analysis the protein encoded by this gene had a molecular mass of 89 kDa, expressing specifically in the testis and localized to the nucleus of stages IV-VIII haploid round spermatids, predominantly at stages VII-VIII of spermatogenesis. ROSBIN is associated with and is most likely phosphorylated by protein kinase A. We suggest that it plays an important role in transcriptional regulation in haploid germ cells.
哺乳动物精子发生是一个在生精小管内以高度协调方式发生的复杂过程。为了阐明控制单倍体生殖细胞分化的分子机制，我们从小鼠睾丸的消减cDNA文库中分离出了单倍体生殖细胞特异性cDNA克隆。其中一个cDNA，即Rosbin，长3.2千碱基（kb），有一个2385个核苷酸的开放阅读框，编码一个795个氨基酸残基的推定蛋白质。计算机介导的同源性搜索显示它包含一个与同源框基因相似的结构域。Northern印迹分析显示在雄性生殖细胞中特异性表达一个3.2-kb的mRNA。在青春期前的睾丸中未观察到Rosbin基因的转录，但在第23天后可检测到。通过Western印迹分析，该基因编码的蛋白质分子量为89 kDa，在睾丸中特异性表达，并定位于IV-VIII期单倍体圆形精子细胞的细胞核，主要在精子发生的VII-VIII期。ROSBIN与蛋白激酶A相关联，很可能被其磷酸化。我们认为它在单倍体生殖细胞的转录调控中起重要作用。
