Molecular analysis of tra-2, a sex determining gene in C.elegans.
Molecular analysis of tra-2, a sex determining gene in C.elegans.
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线虫性别决定基因 tra-2 的分子分析。
DOI：
10.1002/j.1460-2075.1991.tb07933.x
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Kimble,J
中科院分区：
文献类型：
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作者：
Okkema,PG;Kimble,J
我们通过转座子标签法克隆了秀丽隐杆线虫性别决定基因tra-2。通过绘制与11个tra-2突变相关的Southern印迹差异、突变体拯救和tra-2 RNA分析来描绘tra-2区域。tra-2基因编码三种转录本。一种转录物，1.8 kb RNA，在缺乏生殖系的动物中未检测到，因此可能是生殖系特异性的。两种性别的比较表明，成年雌雄同体的tra-2 RNA比成年男性多约15倍。此外，成年雌雄同体含有5 kb和1.8 kb的tra-2 RNA，而成年雄性则含有5 kb和1.9 kb的RNA。在雌雄同体的幼虫发育过程中，在XX生殖系的性别分化之前，也发现了1.9 kb的tra-2 RNA。令人惊讶的是，对选定的性别决定突变体中的tra-2表达的分析表明，tra-2 RNA的性别特异性并不受遗传实验建立的性别决定途径的支配。这一结果可以从两个方面来解释。要么是tra-2 RNA的性别特异性与性表型的调控无关，这似乎不太可能，要么是性别决定基因的层次结构中存在额外的复杂性，例如反馈调控，这确保了tra-2产物与表型性别相对应。
We have cloned the Caenorhabditis elegans sex determining gene, tra‐2, by transposon tagging. The tra‐2 region is delineated by mapping Southern blot differences associated with 11 tra‐2 mutations, mutant rescue, and analysis of tra‐2 RNAs. The tra‐2 gene encodes three transcripts. One transcript, a 1.8 kb RNA, is not detected in animals lacking a germ line, and therefore may be germline specific. Comparison of the two sexes shows that adult hermaphrodites have approximately 15‐fold more tra‐2 RNA than adult males. In addition, adult hermaphrodites contain 5 kb and 1.8 kb tra‐2 RNAs whereas adult males possess 5 kb and 1.9 kb RNAs. A 1.9 kb tra‐2 RNA is also found during hermaphrodite larval development, prior to sexual differentiation of the XX germ line. Surprisingly, analysis of tra‐2 expression in selected sex determination mutants reveals that the sex specificity of tra‐2 RNAs is not dictated by the pathway of sex determination that has been established by genetic experiments. This result can be interpreted in two ways. Either the sex specificity of the tra‐2 RNAs is irrelevant to regulation of the sexual phenotype, which seems unlikely, or there is additional complexity within the hierarchy of sex determining genes, such as feedback regulation, which ensures that the tra‐2 product corresponds to phenotypic sex.