“An Expressed fgf4 Retrogene Is Associated With Breed-Defining Chondrodysplasia in Domestic Dogs.”, Parker, Heidi G. VonHoldt, Bridgett M. Quignon, Pascale Margulies, Elliott H. Shao, Stephanie Mosher, Dana S. Spady, Tyrone C. Elkahloun, Abdel Cargill, Michele Jones, Paul G. Maslen, Cheryl L. Acland, Gregory M. Sutter, Nathan B. Kuroki, Keiichi Bustamante, Carlos D. Wayne, Robert K. Ostrander, Elaine A. Ostrander2009-08-21 (, ; similar)⁠:

Retrotransposition of processed mRNAs is a common source of novel sequence acquired during the evolution of genomes.

Although the vast majority of retroposed gene copies, or retrogenes, rapidly accumulate debilitating mutations that disrupt the reading frame, a small percentage become new genes that encode functional proteins.

By using a multibreed association analysis in the domestic dog, we demonstrate that expression of a recently acquired retrogene encoding fibroblast growth factor 4 (fgf4) is strongly associated with chondrodysplasia, a short-legged phenotype that defines at least 19 dog breeds including dachshund, corgi, and basset hound.

These results illustrate the important role of a single evolutionary event in constraining and directing phenotypic diversity in the domestic dog.