Schedl T, Kimble J
Laboratory of Cell and Molecular Biology, Graduate School, Univesity of Wisconsin, Madison 53706.
Genetics. 1988 May;119(1):43-61. doi: 10.1093/genetics/119.1.43.
This paper describes the isolation and characterization of 16 mutations in the germ-line sex determination gene fog-2 (fog for feminization of the germ line). In the nematode Caenorhabditis elegans there are normally two sexes, self-fertilizing hermaphrodites (XX) and males (XO). Wild-type XX animals are hermaphrodite in the germ line (spermatogenesis followed by oogenesis), and female in the soma. fog-2 loss-of-function mutations transform XX animals into females while XO animals are unaffected. Thus, wild-type fog-2 is necessary for spermatogenesis in hermaphrodites but not males. The fem genes and fog-1 are each essential for specification of spermatogenesis in both XX and XO animals. fog-2 acts as a positive regulator of the fem genes and fog-1. The tra-2 and tra-3 genes act as negative regulators of the fem genes and fog-1 to allow oogenesis. Two models are discussed for how fog-2 might positively regulate the fem genes and fog-1 to permit spermatogenesis; fog-2 may act as a negative regulator of tra-2 and tra-3, or fog-2 may act positively on the fem genes and fog-1 rendering them insensitive to the negative action of tra-2 and tra-3.
本文描述了生殖系性别决定基因fog-2（fog代表生殖系雌性化）中16个突变的分离与特征分析。在线虫秀丽隐杆线虫中，通常有两种性别，即自体受精的雌雄同体（XX）和雄性（XO）。野生型XX动物在生殖系中是雌雄同体（先进行精子发生，随后进行卵子发生），而在体细胞中是雌性。fog-2功能丧失突变会将XX动物转变为雌性，而XO动物不受影响。因此，野生型fog-2对于雌雄同体动物的精子发生是必需的，但对雄性则不是。fem基因和fog-1对于XX和XO动物精子发生的特化都是必不可少的。fog-2作为fem基因和fog-1的正向调节因子。tra-2和tra-3基因作为fem基因和fog-1的负向调节因子，以允许卵子发生。文中讨论了fog-2如何正向调节fem基因和fog-1以允许精子发生的两种模型；fog-2可能作为tra-2和tra-3的负向调节因子，或者fog-2可能对fem基因和fog-1起正向作用，使其对tra-2和tra-3的负向作用不敏感。
