Gallegos M, Ahringer J, Crittenden S, Kimble J
Program of Cellular and Molecular Biology, University of Wisconsin-Madison, 433 Babcock Drive, Room 341E, Madison, WI 53706, USA.
EMBO J. 1998 Nov 2;17(21):6337-47. doi: 10.1093/emboj/17.21.6337.
The fem-3 sex-determining gene is repressed post-transcriptionally via a regulatory element in its 3' untranslated region (UTR) to achieve the switch from spermatogenesis to oogenesis in the Caenorhabditis elegans hermaphrodite germ line. In this paper, we investigate the fem-3 3' UTR control in somatic tissues using transgenic reporter assays, and we also identify six genes essential for this control. First, we find that a reporter transgene bearing a wild-type fem-3 3' UTR is repressed in somatic tissues, whereas one bearing a mutant fem-3 3' UTR is derepressed. Moreover, control by mutant 3' UTRs is temperature sensitive as predicted from the temperature sensitivity of the fem-3 gain-of-function (gf) mutations. Secondly, we find a fem-3 3' UTR RNA-binding activity in somatic tissues, in addition to the previously reported germ-line-specific binding by FBF. Thirdly, we find that each of six genes, mog-1-mog-6, is required for repression by the fem-3 3' UTR. Therefore, the mog genes not only affect the sperm/oocyte switch in the germ line, but also function in somatic tissues. We suggest that the mog genes may encode components of a ubiquitous machinery that is used for fem-3 3' UTR-mediated repression and the sperm/oocyte switch.
在秀丽隐杆线虫雌雄同体生殖系中，fem - 3性别决定基因通过其3'非翻译区（UTR）中的调控元件在转录后被抑制，从而实现从精子发生到卵子发生的转变。在本文中，我们利用转基因报告基因检测法研究了体细胞组织中fem - 3 3' UTR的调控作用，并且还鉴定出了六个对该调控至关重要的基因。首先，我们发现携带野生型fem - 3 3' UTR的报告转基因在体细胞组织中受到抑制，而携带突变型fem - 3 3' UTR的报告转基因则未受抑制。此外，正如从fem - 3功能获得性（gf）突变的温度敏感性所预测的那样，突变型3' UTR的调控具有温度敏感性。其次，除了先前报道的FBF在生殖系中的特异性结合外，我们在体细胞组织中发现了一种fem - 3 3' UTR RNA结合活性。第三，我们发现mog - 1至mog - 6这六个基因中的每一个对于fem - 3 3' UTR的抑制都是必需的。因此，mog基因不仅影响生殖系中的精子/卵子转变，而且在体细胞组织中也发挥作用。我们认为，mog基因可能编码一种普遍存在的机制的组成部分，该机制用于fem - 3 3' UTR介导的抑制作用以及精子/卵子转变。
