Distinctive colour patterns in dogs are an integral component of canine diversity. Colour pattern differences are thought to have arisen from mutation and artificial selection during and after domestication from wolves but important gaps remain in understanding how these patterns evolved and are genetically controlled. In other mammals, variation at the ASIP gene controls both the temporal and spatial distribution of yellow and black pigments. Here, we identify independent regulatory modules for ventral and hair cycle ASIP expression, and we characterize their action and evolutionary origin. Structural variants define multiple alleles for each regulatory module and are combined in different ways to explain five distinctive dog colour patterns. Phylogenetic analysis reveals that the haplotype combination for one of these patterns is shared with Arctic white wolves and that its hair cycle-specific module probably originated from an extinct canid that diverged from grey wolves more than 2 million years ago. Natural selection for a lighter coat during the Pleistocene provided the genetic framework for widespread colour variation in dogs and wolves.
Bibliographical noteFunding Information:
This research was supported by grant no. 31003A_172964 from the Swiss National Science Foundation (T.L.), Maxine Adler Endowed Chair Funds and Hans Sigrist Foundation (D.B.), the Jane and Aatos Erkko Foundation (H.L.) and the Academy of Finland (H.L.). We would like to acknowledge the Next Generation Sequencing Platform of the University of Bern and Biomedicum Functional Genomics Unit, University of Helsinki, for sequencing services and the Interfaculty Bioinformatics Unit of the University of Bern and IT Center For Science Ltd., Finland, for providing high-performance computing infrastructure. We thank resources and members of the Dog Biomedical Variant Database Consortium and all other canine researchers who deposited genome sequencing data into public databases. We thank T. Melling who provided the Tibetan wolf photograph.
© 2021, The Author(s).