Variation in pancreatic amylase gene copy number among Eurasian badgers (Carnivora, Mustelidae, Meles) and its relationship to diet

Occurrence of copy number variation ( CNV ) of gene loci is important in the adaptation of species and populations to their environments. High copy numbers of mammalian genes encoding the digestive enzyme amylase, which plays a role in starch digestion, have been associated with adaptation to high‐starch foods. Here, we investigated CNV in the pancreatic amylase gene ( AMY 2 ) in Eurasian badgers ( Meles species) and related taxa using real‐time quantitative PCR . We found that Meles anakuma and M. meles , as well as the other mustelids Mustela sibirica , Martes melampus and Martes zibellina , had only one copy of the AMY 2 locus, whereas in Meles leucurus the copy number varied between one and four. The AMY 2 copy number also varied significantly among M. leucurus populations. This suggests that M. leucurus is better adapted to a diet rich in starch and/or glycogen than its congeners. As Meles spp. are basically omnivorous but favor a carnivoran diet, for example, earthworms and amphibians, we speculate that the CNV is related to the dearth of animal food in the range of M. leucurus , which enforces a more vegetal diet. This in turn would favor more efficient digestion of dietary starch, which could be achieved by increasing the copy number of AMY2 .