Extensive local adaptation within the chemosensory system following Drosophila melanogaster’s global expansion

• Published in: Nature communications Vol. 7; no. 1; p. ncomms11855
• Main Authors: Arguello, J. Roman, Cardoso-Moreira, Margarida, Grenier, Jennifer K., Gottipati, Srikanth, Clark, Andrew G., Benton, Richard
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13-06-2016; Nature Publishing Group; Nature Portfolio
• Subjects: 631/1647/334/1582/715; 631/181/2474; 631/181/759/2467; 631/378/3917; 64/24; Adaptation; Adaptation, Physiological; Animals; Biology; Drosophila melanogaster - genetics; Drosophila melanogaster - physiology; Drosophila Proteins - genetics; Drosophila Proteins - metabolism; Evolution, Molecular; Gene Expression Profiling; Gene Expression Regulation; Genes, Insect; Genomes; Genomics; Geography; Humanities and Social Sciences; Insects; multidisciplinary; Multigene Family; Mutation - genetics; Neurons; Physiology; Polymorphism, Single Nucleotide - genetics; Proteins; Science; Science (multidisciplinary); Sense Organs - physiology; Signal transduction; New York; United States > US
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms11855

How organisms adapt to new environments is of fundamental biological interest, but poorly understood at the genetic level. Chemosensory systems provide attractive models to address this problem, because they lie between external environmental signals and internal physiological responses. To investigate how selection has shaped the well-characterized chemosensory system of
Drosophila melanogaster
, we have analysed genome-wide data from five diverse populations. By couching population genomic analyses of chemosensory protein families within parallel analyses of other large families, we demonstrate that chemosensory proteins are not outliers for adaptive divergence between species. However, chemosensory families often display the strongest genome-wide signals of recent selection within
D. melanogaster
. We show that recent adaptation has operated almost exclusively on standing variation, and that patterns of adaptive mutations predict diverse effects on protein function. Finally, we provide evidence that chemosensory proteins have experienced relaxed constraint, and argue that this has been important for their rapid adaptation over short timescales.
Fruit flies gain valuable information about their environment by sensing chemicals. Here, Arguello
et al.
show strong signals of recent selection on the chemosensory system of the fruit fly
Drosophila melanogaster
, consistent with the adaptation of populations to their local chemical environment.