The Importance of the Cornell University/Ralston Purina Reference Pedigrees Gary Johnson, DVM, PhD  University of Missouri, Columbia

Summary:

Spectacular advances in human medicine have been greatly facilitated by a highly detailed linkage map of the human genome. Hundreds of laboratories around the world cooperated in the assembly of this map by using DNA markers from their laboratories to analyze DNA from the same reference families. These reference families are known as the CEPH families because DNA was collected and distributed by the Centre d'Etudes du Polymorphisme Humain in France.

Similar reference families have played key roles in the assembly of genome linkage maps for domestic animal species such as the cow and pig. Dr. Gregory Acland and others at Cornell University have collected DNA from canine reference families that are now the basis of the most advanced canine genome linkage maps.

Two years ago, a decision was made to share these markers with other laboratories so that that scientists around the world could help assemble a highly functional linkage map. Nonetheless, legal and administrative issues delayed the release of these markers until the first of July 1999.

Dr. Steven Hannah and others at the Ralston Purina Company have agreed to distribute DNA samples from dogs in these reference pedigrees to qualified laboratories that are interested in adding markers to the linkage map. A four-person panel has been established to assess the qualifications of laboratories wishing to participate. The reference pedigrees consist of eight 3-generation canine families with samples from 98 individual dogs. The genotype data is sent to Drs. Cathryn Mellersh and Elaine Ostrander at the Fred Hutchinson Cancer Research Center for computer analysis and placement of the markers on the canine genome linkage map. We, at the University of Missouri, were among the first to receive DNA samples from the Cornell/Ralston-Purina reference pedigrees. We are using these samples in a one-year project funded by the AKC Canine Health Foundation to place fifty gene-associated markers on the canine genome linkage map. This amounts to about one marker per week. In the first two months since the reference pedigree became available we have added twelve gene associated markers to the canine genome linkage map. Thus, so far, we are slightly ahead of schedule.

Dr. Johnson's work has been supported by the following grants from the AKC Canine Health Foundation:

No. 1275 (Completed): Type I Markers for Canine Homologues of Three Human Chromosomes (Sponsored in part by the Alaskan Malamute Club of America, The American Keeshond Society, Buckeye Keeshond Club and the Keeshond Club of America)

No. 1640: More Type I Markers for the Canine Genome Linkage Map

No. 1826: Placing Type I Markers on the Canine Genome Linkage Map

Biographical Profile

Dr. Gary Johnson is on the faculty in the Department of Veterinary Pathobiology in the College of Veterinary Medicine at the University of Missouri. He has a Bachelors Degree from Augsburg College, a PhD from Kansas State University and a DVM from the University of Minnesota. He has postdoctoral training from Johns Hopkins University and the New York State Department of Health. His early research was on bleeding diseases of dogs. For the last ten years his research has focused on the use of DNA markers to study inherited diseases and quantitative traits in dogs and cattle. Dr. Johnson is a breeder and exhibitor of Irish Terriers.