Intersex, a temperature-sensitive mutant of the nematode Caenorhabditis elegans
1978; Elsevier BV; Volume: 66; Issue: 2 Linguagem: Inglês
10.1016/0012-1606(78)90247-6
ISSN1095-564X
AutoresGregory A. Nelson, Kenneth K. Lew, Samuel Ward,
Tópico(s)Evolution and Genetic Dynamics
ResumoA temperature-sensitive mutation, isx-1(hc17), is reported in the nematode Caenorhabditis elegans which alters the sexual phenotypes of both genotypic sexes. At the restrictive temperature, XX animals are functionally female rather than hermaphroditic due to the absence of spermatogenesis, and XO animals develop as intersexes. These intersexes have normal male head and tail structures and exhibit some mating behavior, but possess hermaphrodite-like gonads which produce no sperm and usually contain a few oocytes. An abortive vulva is usually present and evidence is presented which suggests that the formation of the vulva by the hypodermis is induced by the underlying gonad. The direct effects of the mutation are confined to the descendants of four primordial gonad cells. Gametogenesis and gonad sheath development do not seem to be tightly coupled and are shown to differ in their responses to X-chromosome dosage. The interaction of the intersex mutation with mutant alleles of two transformer genes tra-1 and tra-2 is discussed and a model for the action of these genes in gonad development and sex determination is proposed.
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