Burn T C, Vigoreaux J O, Tobin S L
Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City 73190.
Dev Biol. 1989 Feb;131(2):345-55. doi: 10.1016/s0012-1606(89)80008-9.
The Drosophila actin gene located at cytogenetic position 5C forms at least 9 and perhaps as many as 15 different transcripts with the use of alternative transcriptional start points, differential splicing, and different regions of cleavage/polyadenylation. Each transcript contains one of two alternative 5' exons. We have subcloned unique recombinant DNA probes specific for each separate 5' exon and for three polyadenylation regions into vectors containing T3 and T7 promoters. Single stranded, tritium-labeled RNA probes were generated in vitro from these constructs. These probes have been hybridized in situ to RNA transcripts present in tissue sections from Drosophila embryos. The results of these experiments indicate that transcripts homologous to the two separate 5' exon-specific probes accumulate in strikingly different patterns during Drosophila development. Thus the incorporation of a particular 5' exon into a transcript is correlated with tissue-specific localization of that transcript. In contrast, probes for each of the three polyadenylation regions do not detect any tissue-specific localization of transcripts.
位于细胞遗传学位置5C的果蝇肌动蛋白基因，通过使用可变转录起始点、差异剪接以及不同的切割/聚腺苷酸化区域，形成了至少9种、或许多达15种不同的转录本。每个转录本包含两个可变5'外显子中的一个。我们已经将分别针对每个单独的5'外显子以及三个聚腺苷酸化区域的独特重组DNA探针亚克隆到含有T3和T7启动子的载体中。从这些构建体中体外产生了单链、氚标记的RNA探针。这些探针已原位杂交到果蝇胚胎组织切片中存在的RNA转录本上。这些实验结果表明，与两个单独的5'外显子特异性探针同源的转录本在果蝇发育过程中以明显不同的模式积累。因此，特定5'外显子掺入转录本与该转录本的组织特异性定位相关。相比之下，针对三个聚腺苷酸化区域中每个区域的探针未检测到转录本的任何组织特异性定位。
