Rosenquist T A, Kimble J
Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin, Madison 53706.
Genes Dev. 1988 May;2(5):606-16. doi: 10.1101/gad.2.5.606.
The fem-3 gene is required for specification of the male fate in the nematode Caenorhabditis elegans: XO males need fem-3 for male differentiation in both soma and germ line; XX hermaphrodites need it for the production of sperm. We have cloned fem-3 by transposon tagging. Among eight spontaneous fem-3 mutations generated in a strain in which the transposable element Tc1 is mobile, six contain Tc1 insertions in a 2-kb region of the genome. From this region, we have identified three fem-3 transcripts. Two, 1.7 kb and 1.62 kb, are presented in embryos, and two, 1.62 kb and 1.55 kb, are present in L4s and adults. The fem-3 transcripts are not XO specific; however, in XX adult hermaphrodites, they appear to be limited to the germ line--a tissue involved in male development (both for spermatogenesis and for the maternal contribution of fem-3 to the embryo). The amount of fem-3 RNA in XO embryos is approximately sixfold greater than in XX embryos. The significance of this difference in specifying male development in XO but not in XX embryos is discussed.
在秀丽隐杆线虫中，fem - 3基因对于雄性命运的决定是必需的：XO雄性个体在体细胞和生殖系的雄性分化过程中都需要fem - 3；XX雌雄同体个体产生精子也需要该基因。我们通过转座子标签法克隆了fem - 3基因。在一个可移动转座元件Tc1的品系中产生的8个自发fem - 3突变体里，有6个在基因组的一个2 kb区域含有Tc1插入。从该区域，我们鉴定出了3种fem - 3转录本。两种，即1.7 kb和1.62 kb的转录本出现在胚胎中，两种，即1.62 kb和1.55 kb的转录本存在于L4期幼虫和成虫中。fem - 3转录本并非XO特异性的；然而，在XX成年雌雄同体个体中，它们似乎仅限于生殖系——这是一个与雄性发育相关的组织（对于精子发生以及fem - 3基因向胚胎的母源贡献而言）。XO胚胎中fem - 3 RNA的量大约是XX胚胎中的6倍。本文讨论了这种差异在XO胚胎而非XX胚胎中决定雄性发育的意义。
