title: New candidate genes for sex-comb divergence between Drosophila mauritiana and Drosophila simulans.
abstract: A large-effect QTL for divergence in sex-comb tooth number between Drosophila simulans and D. mauritiana was previously mapped to 73A-84AB. Here we identify genes that are likely contributors to this divergence. We first improved the mapping resolution in the 73A-84AB region using 12 introgression lines and 62 recombinant nearly isogenic lines. To further narrow the list of candidate genes, we assayed leg-specific expression and identified genes with transcript-level evolution consistent with a potential role in sex-comb divergence. Sex combs are formed on the prothoracic (front) legs, but not on the mesothoracic (middle) legs of Drosophila males. We extracted RNA from the prothoracic and mesothoracic pupal legs of two species to determine which of the genes expressed differently between leg types were also divergent for gene expression. Two good functional candidate genes, Scr and dsx, are located in one of our fine-scale QTL regions. In addition, three previously uncharacterized genes (CG15186, CG2016, and CG2791) emerged as new candidates. These genes are located in regions strongly associated with sex-comb tooth number differences and are expressed differently between leg tissues and between species. Further supporting the potential involvement of these genes in sex-comb divergence, we found a significant difference in sex-comb tooth number between co-isogenic D. melanogaster lines with and without P-element insertions at CG2791.
authors.affiliation: Genetics Graduate Group, Center for Genetics and Development, University of California-Davis, 1 Shields Avenue, Davis, CA 95616. rmgraze@ucdavis.edu
authors.forename: Rita M
authors.initials: RM
authors.lastname: Graze
authors.forename: Olga
authors.initials: O
authors.lastname: Barmina
authors.forename: Daniel
authors.initials: D
authors.lastname: Tufts
authors.forename: Elena
authors.initials: E
authors.lastname: Naderi
authors.forename: Kristy L
authors.initials: KL
authors.lastname: Harmon
authors.forename: Maria
authors.initials: M
authors.lastname: Persianinova
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Nuzhdin
mesh_terms: D000825:Animal Structures / Q000033:anatomy & histology; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D004330:Drosophila / Q000033:anatomy & histology* / Q000145:classification / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics; D004331:Drosophila melanogaster / Q000235:genetics; D005121:Extremities / Q000033:anatomy & histology; D005260:Female; D015870:Gene Expression; D017344:Genes, Insect; D005819:Genetic Markers; D008297:Male; D040641:Quantitative Trait Loci; D012727:Sex Characteristics; D013045:Species Specificity
chemical_list: D017931:DNA Primers; D004268:DNA-Binding Proteins; C070369:DSX protein, Drosophila; D029721:Drosophila Proteins; D005819:Genetic Markers