Non-coding changes cause sex-specific wing wize differences between closely related species of Nasonia

• Published in: PLoS genetics Vol. 6; no. 1
• Main Authors: Loehlin, David W, Oliveira, Deodoro C.S.G, Edwards, Rachel, Giebel, Jonathan D, Clark, Michael E, Cattani, M. Victoria, van de Zande, Louis, Verhulst, Eveline C, Beukeboom, Leo W, Munoz-Torres, Monica, Werren, John H
• Format: Journal Article
• Language: English
• Published: Public Library of Science 01.01.2010
• Subjects: Diptera; Genetic aspects; Morphological variation; Physiological aspects; Quantitative trait loci; United States
• ISSN: 1553-7390; 1553-7404
• DOI: 10.1371/journal.pgen.1000821

The genetic basis of morphological differences among species is still poorly understood. We investigated the genetic basis of sex-specific differences in wing size between two closely related species of Nasonia by positional cloning a major male-specific locus, wing-sizel (ws7). Male wing size increases by 45% through cell size and cell number changes when the ws1 allele from N. giraulti is backcrossed into a N. vitripennis genetic background. A positional cloning approach was used to fine-scale map the wsl locus to a 13.5 kilobase region. This region falls between prospero (a transcription factor involved in neurogenesis) and the master sex-determining gene doublesex. It contains the 5'-UTR and cis-regulatory domain of doublesex, and no coding sequence. Wing size reduction correlates with an increase in doublesex expression level that is specific to developing male wings. Our results indicate that non-coding changes are responsible for recent divergence in sex-specific morphology between two closely related species. We have not yet resolved whether wing size evolution at the wsl locus is caused by regulatory alterations of dsx or prospero, or by another mechanism. This study demonstrates the feasibility of efficient positional cloning of quantitative trait loci (QTL) involved in a broad array of phenotypic differences among Nasonia species.