title: Molecular cloning and functional characterization of the sex-determination gene doublesex in the sexually dimorphic broad-horned beetle Gnatocerus cornutus (Coleoptera, Tenebrionidae).
abstract: Various types of weapon traits found in insect order Coleoptera are known as outstanding examples of sexually selected exaggerated characters. It is known that the sex determination gene doublesex (dsx) plays a significant role in sex-specific expression of weapon traits in various beetles belonging to the superfamily Scarabaeoidea. Although sex-specific weapon traits have evolved independently in various Coleopteran groups, developmental mechanisms of sex-specific expression have not been studied outside of the Scarabaeoidea. In order to test the hypothesis that dsx-dependent sex-specific expression of weapon traits is a general mechanism among the Coleoptera, we have characterized the dsx in the sexually dimorphic broad-horned beetle Gnatocerus cornutus (Tenebrionidea, Tenebirionidae). By using molecular cloning, we identified five splicing variants of Gnatocerus cornutus dsx (Gcdsx), which are predicted to code four different isoforms. We found one male-specific variant (GcDsx-M), two female-specific variants (GcDsx-FL and GcDsx-FS) and two non-sex-specific variants (correspond to a single isoform, GcDsx-C). Knockdown of all Dsx isoforms resulted in intersex phenotype both in male and female. Also, knockdown of all female-specific isoforms transformed females to intersex phenotype, while did not affect male phenotype. Our results clearly illustrate the important function of Gcdsx in determining sex-specific trait expression in both sexes.
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Gotoh
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan.
authors.forename: Mai
authors.initials: M
authors.lastname: Ishiguro
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan.
authors.forename: Hideto
authors.initials: H
authors.lastname: Nishikawa
authors.affiliation: Division of Evolutionary Developmental Biology, National Institute for Basic Biology, 38, Nishigonaka, Myodaiji, Okazaki 444-8585, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Morita
authors.affiliation: Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Okada
authors.affiliation: Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Miyatake
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan.
authors.forename: Toshinobu
authors.initials: T
authors.lastname: Yaginuma
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan.|Division of Evolutionary Developmental Biology, National Institute for Basic Biology, 38, Nishigonaka, Myodaiji, Okazaki 444-8585, Japan.|Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan.
authors.forename: Teruyuki
authors.initials: T
authors.lastname: Niimi
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002478:Cells, Cultured; D003001:Cloning, Molecular; D001517:Coleoptera / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics; D019143:Evolution, Molecular; D005260:Female; D018507:Gene Expression Regulation, Developmental; D019476:Insect Proteins / Q000235:genetics*; D007814:Larva; D008297:Male; D020033:Protein Isoforms / Q000235:genetics; D012727:Sex Characteristics; D012733:Sex Differentiation / Q000235:genetics
chemical_list: D004268:DNA-Binding Proteins; C070369:DSX protein, Drosophila; D029721:Drosophila Proteins; D019476:Insect Proteins; D020033:Protein Isoforms