Minami Naojiro, Aizawa Akira, Ihara Ryo, Miyamoto Masakazu, Ohashi Akihiro, Imai Hiroshi
Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
Biol Reprod. 2003 Nov;69(5):1736-42. doi: 10.1095/biolreprod.103.018051. Epub 2003 Jul 30.
We describe a new gene (Oogenesin) that is expressed through oogenesis and early embryogenesis in the mouse. De novo expression starts at 15.5 dpc (days postcoitum) in the ovary, which coincides with the start of oogenesis. The isolated cDNA was 1387 base pairs (bp) in length with a single open reading frame of 326 amino acids corresponding to a predicted molecular mass of 37 kDa with no significant homology to previously reported sequences. A remarkable characteristic of the gene is the presence of a leucine zipper structure at amino acid positions 131-152 and a leucine-rich domain at positions 131-254. Northern blot analysis demonstrated that the mRNA was present only in the ovary, in which it was expressed as a single transcript of approximately 1.7 kb. In situ hybridization revealed distinct signals in the oocytes in follicles at all stages (primordial to antral follicles). Western blot analysis demonstrated that the protein is expressed from oocytes to four-cell-stage embryos and that it has a little larger size (46 kDa) than the predicted size of 37. Immunohistochemical analysis of ovary sections revealed that the protein is also expressed specifically in oocytes in follicles at all stages. Furthermore, immunostaining of preimplantation embryos revealed that the protein localizes in nuclei at the late one-cell and early two-cell stages. These results suggest that the gene has some roles in zygotic transcription of early preimplantation embryos as well as folliculogenesis and oogenesis in the mouse.
我们描述了一种新基因（卵子生成素），它在小鼠的卵子发生和早期胚胎发生过程中表达。从头表达始于卵巢中妊娠15.5天（受精后天数），这与卵子发生的开始时间一致。分离得到的cDNA长度为1387个碱基对（bp），具有一个326个氨基酸的单一开放阅读框，预测分子量为37 kDa，与先前报道的序列无明显同源性。该基因的一个显著特征是在氨基酸位置131 - 152处存在亮氨酸拉链结构，在位置131 - 254处存在富含亮氨酸的结构域。Northern印迹分析表明，mRNA仅存在于卵巢中，在卵巢中它以约1.7 kb的单一转录本形式表达。原位杂交显示在所有阶段（原始卵泡到窦状卵泡）的卵泡卵母细胞中都有明显信号。Western印迹分析表明，该蛋白从卵母细胞表达至四细胞期胚胎，并且其大小（46 kDa）比预测的37 kDa略大。卵巢切片的免疫组织化学分析表明，该蛋白在所有阶段的卵泡卵母细胞中也特异性表达。此外，对植入前胚胎的免疫染色显示，该蛋白在单细胞晚期和二细胞早期定位于细胞核中。这些结果表明，该基因在小鼠早期植入前胚胎的合子转录以及卵泡发生和卵子发生中具有某些作用。
