Koltunow A M, Gregg K, Rogers G E
Nucleic Acids Res. 1986 Aug 26;14(16):6375-92. doi: 10.1093/nar/14.16.6375.
We have shown that chicken feather keratin genes are transcribed at extremely low levels in Xenopus oocytes. Primer extension reactions using carefully selected primers have shown that none of the detectable transcripts are spliced. When the single intron, located in the 5' untranslated region, was removed from the gene, we observed a 5-fold increase in transcript initiation from the in vivo "cap" site. Significantly, this 5-fold increase was also observed when the feather keratin intron was replaced with a similar sized fragment from pBR322. We conclude that the efficiency of accurate transcriptional initiation of chicken feather keratin genes in the oocyte is affected by DNA sequences within the intron.
我们已经证明，鸡毛角蛋白基因在非洲爪蟾卵母细胞中的转录水平极低。使用精心挑选的引物进行的引物延伸反应表明，所有可检测到的转录本均未发生剪接。当位于5'非翻译区的单个内含子从基因中去除后，我们观察到体内“帽”位点的转录起始增加了5倍。值得注意的是，当用pBR322中大小相似的片段替换鸡毛角蛋白内含子时，也观察到了这种5倍的增加。我们得出结论，卵母细胞中鸡毛角蛋白基因准确转录起始的效率受内含子内DNA序列的影响。
