Mapping Refinement of Quantitative Trait Loci for Canine Hip Dysplasia

Posted on by PWDF Admin

Hip dysplasia is one of the most common inherited traits in dogs with an extremely high incidence in some large breeds. It is caused by mutations in multiple genes. In previous studies, investigators discovered the genetic markers that point to the chromosomal regions that harbor the genes that contribute to hip dysplasia.

In this study, they will narrow down these regions through additional genetic evaluation. By narrowing the regions that harbor hip dysplasia genes across breeds, they hope to discover the contributing mutations and use that information to design genetic tests that can be used to prevent the propagation of dysplastic dogs.

Results

Researchers identified the first mutation associated with canine hip dysplasia in Labrador retrievers. This mutation could be used in conjunction with a panel of genetic markers to identify susceptible dogs. The team also learned that there is no single gene identified for hip dysplasia in dogs. This study pointed to several other genes that contribute to the disease, and researchers believe they will discover these genes through the process they have developed.

Based on their findings, the researchers hypothesize that identifying dogs that are resistant to hip dysplasia will involve a panel of genetic markers that may be breed specific. Breeders could then use these panels in conjunction with breeding values to genetically screen puppies before the mutations themselves can be identified. This project lead to the discovery of the first gene associated with canine hip dysplasia.

Co-sponsored with the Morris Animal Foundation, Grant Number: D04CA-135

RESEARCHERS

Rory J. Todhunter, BVSc, PhD
Cornell University

Gene Expression Profiling of Relapsed Lymphoma in Dogs

Posted on by PWDF Admin

Lymphoma is one of the most common cancers in dogs. Breeds with a high incidence include Boxers, Golden Retrievers, and German Shepherds. It is also one of the most treatable cancers – more than 90 percent of dogs treated with chemotherapy go into remission. Unfortunately, most dogs relapse and eventually die from the disease.

Results

The investigators compared gene-expression patterns of tumors before and after chemotherapy to determine changes that took place in the dogs that relapsed. They identified important candidate genes and different subtypes of lymphoma that will help in the development of new cancer treatments. These candidate genes must now be independently validated in another set of patient samples but have already contributed greatly to the understanding of genes associated with relapse and potential new therapeutic targets.

Co-sponsored with the Morris Animal Foundation, Grant Number: D03CA-132

RESEARCHERS

W. C. Kisseberth, DVM, PhD
Dip. ACVIM (Oncology)
Ohio State University

Characterizing the Inheritance of Addison’s Disease and Linked DNA Markers

Posted on by PWDF Admin

Addison’s disease is a late onset disorder caused by the deterioration of the adrenal gland. Addison’s occurs in the domestic dog at approximately 0.1 percent, with some breeds showing a greater prevalence. Notably, the Bearded Collie, the West Highland White Terrier, the Standard Poodle, the Portuguese Water Dog, and the Leonberger are considered to have unacceptable rates of Addison’s disease. Breeders have noted a familial tendency of Addison’s disease suggesting a genetic basis to the disorder.

Results

Our laboratory has determined that Addison’s is highly heritable in Bearded Collies. Further, although Addison’s is not fully governed by a single locus in the Bearded Collie, it does appear to be regulated by a single gene of large effect.

The specific objectives of this study are to develop a genetic marker associated with an Addison’s locus in the Bearded Collie; such a genetic marker will provide a useful tool to aid breeders in making health-based breeding decisions. The second objective is to determine if Addison’s disease in the Standard Poodle, West Highland White Terrier, Portuguese Water Dog and Leonberger also has a genetic basis and if so, whether there is a common genetic defect across all these breeds.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 0002226

RESEARCHERS

Anita M. Oberbauer, PhD
University of California at Davis