Zarkower D, De Bono M, Aronoff R, Hodgkin J
Medical Research Council Laboratory of Molecular Biology, Cambridge, England.
Dev Genet. 1994;15(3):240-50. doi: 10.1002/dvg.1020150306.
The tra-1 gene is the terminal regulator in the sex determination pathway in C. elegans, directing all aspects of somatic sexual differentiation. Recessive loss-of-function (lf) mutations in tra-1 masculinize XX animals (normally somatically female), while dominant gain-of-function mutations feminize XO animals (normally male). Most tra-1 (lf) mutations can be fitted into a simple allelic series of somatic masculinization, but a small number of lf alleles do not fit into this series. Here we show that three of these mutations are associated with DNA rearrangements 5' to the coding region. One allele is an inversion that may be subject to a position effect. We also report the isolation of a new class of tra-1 alleles that are responsive to mutations in the smg system of RNA surveillance. We show that two of these express RNAs of aberrant size. We suggest that the smg-sensitive mutations may identify a carboxy-terminal domain required for negative regulation of tra-1 activity.
tra-1基因是秀丽隐杆线虫性别决定途径中的终末调节因子，指导体细胞性分化的各个方面。tra-1基因的隐性功能丧失（lf）突变使XX动物（正常情况下体细胞为雌性）雄性化，而显性功能获得突变使XO动物（正常情况下为雄性）雌性化。大多数tra-1（lf）突变可归入体细胞雄性化的简单等位基因系列，但少数lf等位基因不符合该系列。在这里，我们表明这些突变中的三个与编码区5'端的DNA重排有关。一个等位基因是倒位，可能受到位置效应的影响。我们还报告了一类新的tra-1等位基因的分离，这些等位基因对RNA监测的smg系统中的突变有反应。我们表明其中两个表达异常大小的RNA。我们认为，对smg敏感的突变可能识别出tra-1活性负调控所需的羧基末端结构域。
