Evidence from mosaic analysis of the masculinizing gene her-1 for cell interactions in C. elegans sex determination.
Sex in Caenorhabditis elegans is determined by a regulatory cascade of seven interacting autosomal genes controlled by three X-linked genes in response to the X chromosome-to-autosome (X/A) ratio. XX animals (high X/A) develop as self-fertile hermaphrodites, and XO animals (low X/A) develop as males. The activity of the first gene in the sex-determining cascade, her-1, is required for male sexual development. XO her-1 loss-of-function mutants develop as self-fertile hermaphrodites, whereas XX her-1 gain-of-function mutants develop as masculinized intersexes. By genetic mosaic analysis using a fused free duplication linking her-1 to a cell-autonomous marker gene, we show here that her-1 expression in a sexually dimorphic cell is neither necessary nor sufficient for that cell to adopt a male fate. Our results suggest that her-1 is expressed in many, possibly all, cells and that its gene product can function non-autonomously through cell interactions to determine male sexual development.
Hunter
C P
CP
Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder 80309-0347.
Wood
W B
WB
D000818:Animals; D002107:Caenorhabditis / Q000235:genetics*; D002874:Chromosome Mapping; D012734:Disorders of Sex Development / Q000235:genetics; D004303:Dosage Compensation, Genetic; D005260:Female; D005786:Gene Expression Regulation; D008297:Male; D009030:Mosaicism; D009154:Mutation; D010375:Pedigree; D010641:Phenotype; D012732:Sex Determination Analysis