Sex and X-Chromosome-wide Repression in Caenorhabditiselegans
This extract was created in the absence of an abstract.
Excerpt
In many organisms, sex is determined by a precisechromosome counting mechanism that distinguishes onesex chromosome from two. In flies and worms, for example, XX embryos become females (orhermaphrodites), while XO or XY embryos becomemales (Fig. 1a) (Bridges 1916; Nigon 1951; Madl andHerman 1979). Sex can also be specified by the merepresence of a particular sex chromosome, such as the Ychromosome of mammals: XY or XXY embryos aremales, and XX embryos females (Gubbay et al. 1990;Sinclair et al. 1990; Koopman et al. 1991). These sex-determining mechanisms cause the two sexes to differ intheir dose of X chromosomes, yet both sexes requireequivalent levels of X-chromosome gene products. Achromosome-wide regulatory process called dosage compensation neutralizes the difference in X-linked genedose between males and females by equalizing X-chromosome transcript levels...
