Gain-of-function mutations of fem-3, a sex-determination gene in Caenorhabditis elegans.
Gain-of-function mutations of fem-3, a sex-determination gene in Caenorhabditis elegans.
复制标题
fem-3（秀丽隐杆线虫性别决定基因）的功能获得突变。
DOI：
10.1093/genetics/115.1.107
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发表时间：
1987
期刊：
影响因子：
3.3
通讯作者：
Kimble,J
中科院分区：
文献类型：
--
作者：
Barton,MK;Schedl,TB;Kimble,J
我们分离出性别决定基因fem-3的九个功能获得（gf）等位基因，作为fem-1和fem-2女性化突变的抑制因子。野生型fem-3基因对于XX自体受精雌雄同体的精子发生以及对于XO动物的体细胞和生殖系的雄性发育来说是必需的。功能丧失等位基因offem-3将XX和XO动物转化为雌性（无精子的雌雄同体）。相反，fem-3(gf) 等位基因仅使一种组织男性化，即雌雄同体种系。因此，XX fem-3(gf) 突变动物具有正常的雌雄同体体细胞，但生殖系产生大量过量的精子而没有卵母细胞。所有 ninefem-3(gf) 等位基因均对温度敏感。温度敏感期是从 L4 晚期到成体早期，即卵子发生最初迹象之前的时期。功能获得等位基因赋予与功能丧失等位基因相反的表型，这一发现支持了 fem-3 在种系性别决定中发挥关键作用的观点。此外，fem-3(gf)突变体表型的种系特异性和晚期温度敏感期表明，在野生型XX雌雄同体中，fem-3受到负调控，使得雌雄同体停止产生精子并开始产生卵母细胞。温度变化实验还表明，在种系中，性承诺似乎是一个持续的过程。即使在卵子发生开始后，精子发生也可以恢复，并且卵子发生可以比正常情况晚得多
We have isolated nine gain-of-function (gf) alleles of the sex-determination genefem-3as suppressors of feminizing mutations infem-1andfem-2. The wild-typefem-3gene is needed for spermatogenesis inXXself-fertilizing hermaphrodites and for male development in both soma and germ line ofXOanimals. Loss-of-function alleles offem-3transformXXandXOanimals into females (spermless hermaphrodites). In contrast,fem-3(gf) alleles masculinize only one tissue, the hermaphrodite germ line. Thus,XX fem-3(gf) mutant animals have a normal hermaphrodite soma, but the germ line produces a vast excess of sperm and no oocytes. All ninefem-3(gf) alleles are temperature sensitive. The temperature-sensitive period is from late L4 to early adult, a period just preceding the first signs of oogenesis. The finding of gain-of-function alleles which confer a phenotype opposite to that of loss-of-function alleles supports the idea thatfem-3plays a critical role in germ-line sex determination. Furthermore, the germ-line specificity of thefem-3(gf) mutant phenotype and the late temperature-sensitive period suggest that, in the wild-typeXXhermaphrodite,fem-3is negatively regulated so that the hermaphrodite stops making sperm and starts making oocytes. Temperature shift experiments also show that, in the germ line, sexual commitment appears to be a continuing process. Spermatogenesis can resume even after oogenesis has begun, and oogenesis can be initiated much later than normal