Nagano M, Koga C, Tashiro K, Kugawa F, Shiokawa K
Department of Biological Sciences, Graduate School of Science, University of Tokyo, Japan.
Biochem Biophys Res Commun. 1997 Feb 24;231(3):561-5. doi: 10.1006/bbrc.1997.6120.
With a final goal to study how TBP-binding repressor Dr1 regulates transcription in Xenopus early embryos, we cloned its cDNA from Xenopus liver cDNA library. The cDNA was 1,986 bp long, with the open reading frame coding for 175 amino acids, whose sequence was highly homologous to its human counterpart. Xenopus Dr1 mRNA was expressed from the earliest stage of oogenesis, inherited as maternal mRNA at a high level, but its level became low at and after the neurula stage where RNA synthetic activity is strongly activated. Dr1 mRNA occurred in larger amounts in the animal half than in the vegetal half in 8-cell stage embryos, and in neurula and tailbud stage embryos its distribution was slightly larger in the anterior part than in the posterior part. These data show that Dr1 mRNA is expressed in a temporally and spatially regulated manner, and its occurrence at higher levels in earlier stage embryos may be responsible for their low transcriptional activity.
为了最终研究TBP结合阻遏物Dr1如何调控非洲爪蟾早期胚胎中的转录，我们从非洲爪蟾肝脏cDNA文库中克隆了其cDNA。该cDNA长1986 bp，开放阅读框编码175个氨基酸，其序列与人类对应序列高度同源。非洲爪蟾Dr1 mRNA从卵子发生的最早阶段开始表达，作为母源mRNA高水平遗传，但在神经胚期及之后，当RNA合成活性被强烈激活时，其水平降低。在8细胞期胚胎中，Dr1 mRNA在动物半球的含量比植物半球多，在神经胚和尾芽期胚胎中，其在前部的分布略大于后部。这些数据表明，Dr1 mRNA以时间和空间调控的方式表达，其在早期胚胎中较高水平的出现可能是其低转录活性的原因。
