Genetics, Vol 139, 1649-1661, Copyright © 1995

INVESTIGATIONS

A Genetic Analysis of intersex, a Gene Regulating Sexual Differentiation in Drosophila melanogaster Females

B. A. Chase and B. S. Baker
Department of Biological Sciences, Stanford University, Stanford, California 94305 and Department of Biology, University of Nebraska, Omaha, Nebraska 68182

Sex-type in Drosophila melanogaster is controlled by a hierarchically acting set of regulatory genes. At the terminus of this hierarchy lie those regulatory genes responsible for implementing sexual differentiation: genes that control the activity of target loci whose products give rise to sexually dimorphic phenotypes. The genetic analysis of the intersex (ix) gene presented here demonstrates that ix is such a terminally positioned regulatory locus. The ix locus has been localized to the cytogenetic interval between 47E3-6 and 47F11-18. A comparison of the morphological and behavioral phenotypes of homozygotes and hemizygotes for three point mutations at ix indicates that the null phenotype of ix is to transform diplo-X animals into intersexes while leaving haplo-X animals unaffected. Analysis of X-ray induced, mitotic recombination clones lacking ix(+) function in the abdomen of diplo-X individuals indicates that the ix(+) product functions in a cell-autonomous manner and that it is required at least until the termination of cell division in this tissue. Taken together with previous analyses, our results indicate that the ix(+) product is required to function with the female-specific product of doublesex to implement appropriate female sexual differentiation in diplo-X animals.

This article has been cited by other articles:

				Y. Yang, W. Zhang, J. R. Bayrer, and M. A. Weiss Doublesex and the Regulation of Sexual Dimorphism in Drosophila melanogaster: STRUCTURE, FUNCTION, AND MUTAGENESIS OF A FEMALE-SPECIFIC DOMAIN J. Biol. Chem., March 14, 2008; 283(11): 7280 - 7292. [Abstract] [Full Text] [PDF]

				L. O. F. Penalva and L. Sanchez RNA Binding Protein Sex-Lethal (Sxl) and Control of Drosophila Sex Determination and Dosage Compensation Microbiol. Mol. Biol. Rev., September 1, 2003; 67(3): 343 - 359. [Abstract] [Full Text] [PDF]

				C. M. Garrett-Engele, M. L. Siegal, D. S. Manoli, B. C. Williams, H. Li, and B. S. Baker intersex, a gene required for female sexual development in Drosophila, is expressed in both sexes and functions together with doublesex to regulate terminal differentiation Development, March 12, 2003; 129(20): 4661 - 4675. [Abstract] [Full Text] [PDF]

				C Schutt and R Nothiger Structure, function and evolution of sex-determining systems in Dipteran insects Development, January 2, 2000; 127(4): 667 - 677. [Abstract] [PDF]

				J. A. Waterbury, L. L. Jackson, and P. Schedl Analysis of the Doublesex Female Protein in Drosophila melanogaster: Role in Sexual Differentiation and Behavior and Dependence on Intersex Genetics, August 1, 1999; 152(4): 1653 - 1667. [Abstract] [Full Text]

				H Li and B. Baker hermaphrodite and doublesex function both dependently and independently to control various aspects of sexual differentiation in Drosophila Development, January 7, 1998; 125(14): 2641 - 2651. [Abstract] [PDF]

				H Li and B. Baker Her, a gene required for sexual differentiation in Drosophila, encodes a zinc finger protein with characteristics of ZFY-like proteins and is expressed independently of the sex determination hierarchy Development, January 1, 1998; 125(2): 225 - 235. [Abstract] [PDF]

				Enhancer of Polycomb Is a Suppressor of Position-Effect Variegation in Drosophila melanogaster Genetics, January 1, 1998; 148(1): 211 - 220.