AKC Gazette January 2004

Tasha and the Canine Genome

A flashy fawn female Boxer named Tasha has donated her blood to become the model for unraveling the mysteries of the canine genome, containing some 2.8 billion DNA pairs. The study of the genome sequence is actually a study of the form and function of all of the genes that make up a given organism. This project is being conducted at the Whitehead Institute/MIT Center for Genome Research in Cambridge, MA. Expected to cost some $50 million and to be completed in 2004, the mapping of the canine gene and all the chromosomes that comprise it is a part of the overall study of the human genome of the National Human Genome Research Institute at the National Institute of Health in Bethesda, MD. Comparison of the human gene sequencing to that of the dog will be vital in understanding essential species variations and to study many inherited health disorders.

Why the Boxer, you might ask? Well, the answer is somewhat disturbing. Of the more than 150 breeds of dogs, scientists selected the Boxer because of its relative lack of variance in its genome sequence—thus mapping it will be easier than that of other breeds. The reason? Because the gene pool of the Boxer is so small, despite its #7 standing in the AKC registration statistics, that all Boxers are essentially very similar “under the skin.” Facts to remember the next time Boxer breeders sit around and discuss all of the health concerns that plague our dogs—heart disease, cancers in so many forms, thyroid disorders, and degenerative myelopathy. Are we reinforcing health problems every time we plan a mating? Should we be waiting to use older stud dogs which are…say…5 years of age and seem in good health?

Perhaps we can lay our lack of genetic diversity at the feet of the relatively few boxer breeders that refined the breed in Germany in the 19th century. Or the 4 foundation sires from Germany who produced almost all the USA Boxers in an unbroken line from the 1930s. Whatever the reason, the relatively small amount of diversity surely bears further study in terms of future directions to take for generations yet unborn. It would be interesting to know whether or not Boxers from the UK or the Continent are similarly lacking in genetic variation.

Stephanie Abraham
P. O. Box 346
Scotland, CT 06264