SEX DETERMINATION IN DROSOPHILA-MELANOGASTER - ANALYSIS OF TRANSFORMER-2, A SEX-TRANSFORMING LOCUS

The transformer-2 (tra-2) locus is one of a set of regulatory loci that control sex determination in D. melanogaster. Temperature-shift experiments with temperature-sensitive tra-2 mutants demonstrate that within single cell lineages tra-2+ function is required at several times, and probably continuously, during development for the occurrence of a series of determinative decisions necessary for female sexual differentiation. Analysis of the effects of tra-2 in the genital disc demonstrates that the tra-2+ function is necessary in females both to prevent male sexual differentiation and to permit female differentiation. The tra-2+ and tra+ loci apparently act to control the expression of the bifunctional doublesex (dsx) locus.