Rao J P, Zafar R S, Sodja A
Department of Biological Sciences, Wayne State University, Detroit, MI.
Biochim Biophys Acta. 1988 May 6;950(1):30-44. doi: 10.1016/0167-4781(88)90070-x.
Polyribosomal poly(A)+ RNA from stage-specific embryos of Drosophila melanogaster was analyzed by Northern hybridizations to determine the transcription at the 5C actin gene (act5C) and to establish whether these mRNAs are used in translation. A 3' end probe, which contains 30 nucleotides of the actin coding sequence as well as 3'-end-adjacent sequence, hybridizes in addition to the act5C transcript to a smaller transcript 450 nucleotides long. Hybridizations with the 3' end strand-specific probes show that this transcript has the same orientation as the actin gene. This transcript is temporally coexpressed with the act5C gene over most of the developmental stages examined. S1 nuclease mapping and primer extension experiments place its 5' end about 20 nucleotides upstream from the actin translation termination signal. Furthermore, the transcript appears to translate in an in vitro translation system into a protein of 7.4 kDa, as expected from the size of the open reading frame. The data suggest, but do not prove, that the 3'-end-transcribed but untranslated region of act5C may be involved in actin gene expression.
通过Northern杂交分析了黑腹果蝇特定发育阶段胚胎中的多核糖体多聚腺苷酸（poly(A)+）RNA，以确定5C肌动蛋白基因（act5C）的转录情况，并确定这些mRNA是否用于翻译。一个3'端探针，包含30个核苷酸的肌动蛋白编码序列以及3'端相邻序列，除了与act5C转录本杂交外，还与一个450个核苷酸长的较小转录本杂交。用3'端链特异性探针进行杂交表明，该转录本与肌动蛋白基因具有相同的方向。在大多数检测的发育阶段，该转录本与act5C基因在时间上共表达。S1核酸酶图谱分析和引物延伸实验表明，其5'端位于肌动蛋白翻译终止信号上游约20个核苷酸处。此外，该转录本在体外翻译系统中似乎能翻译成一个7.4 kDa的蛋白质，这与开放阅读框的大小预期相符。数据表明，但并未证明，act5C的3'端转录但未翻译区域可能参与肌动蛋白基因的表达。
