Schmidt R, Hediger M, Nöthiger R, Dübendorfer A
Institute of Zoology, University of Zürich, Switzerland.
Genetics. 1997 Jan;145(1):173-83. doi: 10.1093/genetics/145.1.173.
In Musca domestica, the primary signal for sex determination is the dominant factor M, which is assumed to regulate a postulated female-determining gene F. Presence of M prevents expression of F so that male development ensues. In the absence of M, F can become active, which dictates the female pathway. The existence of F is inferred from FD. a dominant factor that is epistatic to M. We describe a new mutation masculinizer, which has all the properties expected for a null or strongly hypomorphic allele of F: (1) it maps to the same chromosomal location as FD, (2) homozygous man/man animals develop as males, (3) homozygous man/man clones generated in man/+ female larvae differentiate male structures, (4) man has a sex-determining maternal effect. About a third of the morphological males synthesize yolk proteins, which indicates that they are intersexual in internal structures. The maternal effect of man is complete in offspring that derive from homozygous man/man pole cells transplanted into female hosts. In this case, all man/+ progeny become fertile males that do not produce yolk proteins A sex-determining maternal effect has previously been demonstrated for FD. Like F, maternal man' is needed for zygotic man' to become active, providing further evidence that man is a loss-of-function allele of F.
在家蝇中，性别决定的主要信号是显性因子M，假定它调控一个假定的雌性决定基因F。M的存在会阻止F的表达，从而导致雄性发育。在没有M的情况下，F会变得活跃，这决定了雌性发育途径。F的存在是从FD推断出来的，FD是一个对M上位的显性因子。我们描述了一个新的突变体“雄性化因子”，它具有F的无效或强亚效等位基因所预期的所有特性：（1）它与FD位于相同的染色体位置，（2）纯合的man/man动物发育为雄性，（3）在man/+雌性幼虫中产生的纯合man/man克隆分化为雄性结构，（4）man具有性别决定的母体效应。大约三分之一的形态学雄性合成卵黄蛋白，这表明它们在内部结构上是雌雄同体的。man的母体效应在将纯合man/man极细胞移植到雌性宿主所产生的后代中是完全的。在这种情况下，所有man/+后代都成为可育的雄性，不产生卵黄蛋白。之前已经证明FD具有性别决定的母体效应。与F一样，合子中的man需要母体的man才能变得活跃，这进一步证明man是F的功能缺失等位基因。
