Why do domestic dogs vary so much in size, shape, coat texture, color and patterning?
There are more than 300 dog breeds in the world, including 170 recognized by the American Kennel Club. All are members of the species Canis familiaris. The authors review unique features of the canine genome that make it particularly good for genetic studies, and they show that breeds can be divided into five major groups derived from groups of ancient forebears. “Study of variation in the dog species, with its breeding structure, helps us hone in on the genomic factors for traits shared across species, including analogs for diseases that occur in the human population,” said senior author Elaine Ostrander, Ph.D., chief of NHGRI’s Cancer Genetics Branch. This essay highlights the unique features of dog populations that offer advantages for genetic studies, as well as recent advances in canine genomics that show how genetic mechanisms may control breed-defining traits. For example, the hunt for genes for a prominent trait in more than one breed (such as short legs) is simplified because
