Scientists Discover the Gene that Controls Dog Size

Despite the huge variation in body size and shape, Great Danes and Chihuahuas are both members of the same species: Canis lupus familiaris. Now, a new study conducted by an international team of scientists led by researchers at the National Human Genome Research Institute (NHGRI) has identified the gene responsible for this great range of dog sizes. The answer, it seems involve a number of different versions of the gene that encodes for insulin-like growth factor 1 (IGF1). The gene, IGF1, was identified following genetic analysis that began with screening 463 Portuguese water dogs, a breed that has a lot of diversity in size