title: Dietary Variation and Evolution of Gene Copy Number among Dog Breeds.
abstract: Prolonged human interactions and artificial selection have influenced the genotypic and phenotypic diversity among dog breeds. Because humans and dogs occupy diverse habitats, ecological contexts have likely contributed to breed-specific positive selection. Prior to the advent of modern dog-feeding practices, there was likely substantial variation in dietary landscapes among disparate dog breeds. As such, we investigated one type of genetic variant, copy number variation, in three metabolic genes: glucokinase regulatory protein (GCKR), phytanol-CoA 2-hydroxylase (PHYH), and pancreatic α-amylase 2B (AMY2B). These genes code for proteins that are responsible for metabolizing dietary products that originate from distinctly different food types: sugar, meat, and starch, respectively. After surveying copy number variation among dogs with diverse dietary histories, we found no correlation between diet and positive selection in either GCKR or PHYH. Although it has been previously demonstrated that dogs experienced a copy number increase in AMY2B relative to wolves during or after the dog domestication process, we demonstrate that positive selection continued to act on amylase copy number in dog breeds that consumed starch-rich diets in time periods after domestication. Furthermore, we found that introgression with wolves is not responsible for deterioration of positive selection on AMY2B among diverse dog breeds. Together, this supports the hypothesis that the amylase copy number expansion is found universally in dogs.
authors: Human Evolutionary Biology, Harvard University, 11 Divinity Avenue, Cambridge, MA, 02138, United States of America.
authors: Taylor
authors: T
authors: Reiter
authors: Human Evolutionary Biology, Harvard University, 11 Divinity Avenue, Cambridge, MA, 02138, United States of America.
authors: Evelyn
authors: E
authors: Jagoda
authors: Human Evolutionary Biology, Harvard University, 11 Divinity Avenue, Cambridge, MA, 02138, United States of America.
authors: Terence D
authors: TD
authors: Capellini
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics; D000821:Animal Feed; D000818:Animals; D050260:Carbohydrate Metabolism; D055028:Comparative Genomic Hybridization; D056915:DNA Copy Number Variations; D004032:Diet; D004285:Dogs / Q000235:genetics*; D019143:Evolution, Molecular; D018628:Gene Dosage; D006899:Mixed Function Oxygenases / Q000235:genetics; D055292:Pancreatic alpha-Amylases / Q000235:genetics
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D006899:Mixed Function Oxygenases; D055292:Pancreatic alpha-Amylases