title: Association between sex-biased gene expression and mutations with sex-specific phenotypic consequences in Drosophila.
abstract: Genome-wide mRNA transcription profiles reveal widespread molecular sexual dimorphism or "sex-biased" gene expression, yet the relationship between molecular and phenotypic sexual dimorphism remains unclear. A major unresolved question is whether sex-biased genes typically perform male- and female-specific functions (whether these genes have sex-biased phenotypic or fitness consequences) or have similar functional importance for both sexes. To elucidate the relationship between sex-biased transcription and sex-biased fitness consequences, we analyzed a large data set of lethal, visible, and sterile mutations that have been mapped to the Drosophila melanogaster genome. The data permitted us to classify genes according to their sex-specific mutational effects and to infer the relationship between sex-biased transcription level and sex-specific fitness consequences. We find that mutations in female-biased genes are (on average) more deleterious to females than to males and that mutations in male-biased genes tend to be more deleterious to males than to females. Nevertheless, mutations in most sex-biased genes have similar phenotypic consequences for both sexes, which suggests that sex-biased transcription is not necessarily associated with functional genetic differentiation between males and females. These results have interesting implications for the evolution of sexual dimorphism and sex-specific adaptation.
authors.affiliation: Department of Molecular Biology and Genetics, Cornell University, USA. tmc233@cornell.edu
authors.forename: Tim
authors.initials: T
authors.lastname: Connallon
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Clark
mesh_terms: D000818:Animals; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D008297:Male; D009154:Mutation; D010641:Phenotype; D012727:Sex Characteristics; D013045:Species Specificity
chemical_list: D029721:Drosophila Proteins