title: Genome-wide transcription analysis of clinal genetic variation in Drosophila.
abstract: Clinal variation in quantitative traits is widespread, but its genetic basis awaits identification. Drosophila melanogaster shows adaptive, clinal variation in traits such as body size along latitudinal gradients on multiple continents. To investigate genome wide transcription differentiation between North and South that might contribute to the clinal phenotypic variation, we compared RNA expression patterns during development of D. melanogaster from tropical northern and temperate southern populations using whole genome tiling arrays. We found that genes that were differentially expressed between the cline ends were generally associated with metabolism and growth, and experimental alteration of expression of a sample of them generally resulted in altered body size in the predicted direction, sometimes significantly so. We further identified the serpent (srp) transcription factor binding sites to be enriched near genes up-regulated in expression in the south. Analysis of clinal populations revealed a significant cline in the expression level of srp. Experimental over-expression of srp increased body size, as predicted from its clinal expression pattern, suggesting that it may be involved in regulating adaptive clinal variation in Drosophila. This study identified a handful of genes that contributed to clinal phenotypic variation through altered gene expression level, yet misexpression of individual gene led to modest body size change.
authors.affiliation: Department of Genetics, Evolution and Environment, University College London, London, United Kingdom.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.forename: Siu F
authors.initials: SF
authors.lastname: Lee
authors.forename: Eric
authors.initials: E
authors.lastname: Blanc
authors.forename: Caroline
authors.initials: C
authors.lastname: Reuter
authors.forename: Bregje
authors.initials: B
authors.lastname: Wertheim
authors.forename: Pedro
authors.initials: P
authors.lastname: Martinez-Diaz
authors.forename: Ary A
authors.initials: AA
authors.lastname: Hoffmann
authors.forename: Linda
authors.initials: L
authors.lastname: Partridge
mesh_terms: D000818:Animals; D001665:Binding Sites; D004330:Drosophila / Q000033:anatomy & histology / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics; D050980:GATA Transcription Factors / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics*; D055106:Genome-Wide Association Study / Q000379:methods*; D014921:Wings, Animal / Q000033:anatomy & histology / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D050980:GATA Transcription Factors; C103965:srp protein, Drosophila