Journal of Heredity Advance Access originally published online on June 15, 2005
Journal of Heredity 2005 96(7):750-754; doi:10.1093/jhered/esi078
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Exclusion of Urate Oxidase as a Candidate Gene for Hyperuricosuria in the Dalmatian Dog Using an Interbreed Backcross
From the Department of Population Health and Reproduction (Safra and Bannasch) and the Department of Medicine and Epidemiology (Ling), School of Veterinary Medicine, University of California, Davis, CA 95616; and the Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Purdue University West Lafayette, IN 47907 (Schaible)
Address correspondence to Danika Bannasch, DVM, PhD, Department of Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA 95616, or e-mail: dlbannasch{at}ucdavis.edu.
Hyperuricosuria, an autosomal recessive disorder, is characterized by high levels of uric acid in the urine of Dalmatian dogs. Whereas high levels of uric acid are known to be caused by the silencing of the urate oxidase (uox) gene in humans and higher primates, the molecular basis for the Dalmatian defect is unknown. Transplantation studies show that the organ responsible for the Dalmatian phenotype is the liver, which is where urate oxidase is exclusively expressed and uric acid is converted into allantoin. We cloned and sequenced the canine uox cDNA and compared the sequence between a Dalmatian and non-Dalmatian dog. No change in cDNA sequence was identified. A Dalmatian x pointer backcross family was used to track the segregation of microsatellite markers surrounding the urate oxidase locus. The uox gene was excluded for Dalmatian hyperuricosuria based on the cDNA sequence identity and negative LOD scores.