Sizing Up Man’s Best Friend

Science's STKE  10 Apr 2007:
Vol. 2007, Issue 381, pp. tw128
DOI: 10.1126/stke.3812007tw128

In contrast to most mammalian species, Canis familiaris (the domestic dog) shows extreme diversity in body size. Sutter et al. show that a single allele of the gene encoding insulin-like growth factor-1 (IGF-1) is shared by all small dog breeds but is nearly absent from giant dog breeds, implying that sequence variation in the IGF-1 gene plays a causal role in dog size. Discovery of the IGF-1 gene was facilitated by its localization within a genomic signature, or haplotype block, that probably arose as a result of centuries of dog breeding by humans.

N. B. Sutter, C. D. Bustamante, K. Chase, M. M. Gray, K. Zhao, L. Zhu, B. Padhukasahasram, E. Karlins, S. Davis, P. G. Jones, P. Quignon, G. S. Johnson, H. G. Parker, N. Fretwell, D. S. Mosher, D. F. Lawler, E. Satyaraj, M. Nordborg, K. G. Lark, R. K. Wayne, E. A. Ostrander, A single IGF1 allele is a major determinant of small size in dogs. Science 316, 112-115 (2007). [Abstract] [Full Text]