The Canine POMC Gene, Obesity in Labrador Retrievers and Susceptibility to Diabetes Mellitus.
BACKGROUND
Diabetes mellitus (DM) in dogs is a common endocrinopathy with a complex genetic architecture. Disease susceptibility in several breeds is associated with polymorphisms in immune response genes, but in the Labrador retriever breed, no genetic associations with DM have been identified. A deletion in the pro-opiomelanocortin (POMC) gene in Labrador retrievers is associated with increased appetite and risk of obesity.


OBJECTIVE
To characterize the POMC deletion in Labrador retrievers, to develop a simple genetic test for this mutation, and to test the hypothesis that the POMC gene deletion is associated with an increased risk of DM in this breed.


METHODS
Sixty-one non-diabetic Labrador retrievers aged >6 years and 57 Labrador retrievers with DM.


METHODS
Case-control genotyping study to compare the frequency of the POMC deletion in dogs with and without DM. After polymerase chain reaction (PCR) and sequencing to characterize the mutation, a PCR-based test was developed and validated using 2 different restriction fragment length polymorphism assays.


RESULTS
A 14-base-pair deletion was confirmed and localized to exon 3 of the canine POMC gene. A PCR-based test for the deletion was successfully developed. There was no association between the presence of the POMC deletion mutation and DM in this population of Labrador retriever dogs (P = .31).


CONCLUSIONS
This study adds to the existing scientific literature indicating that there is little evidence for a direct link between obesity and DM in dogs.
Department of Veterinary Medicine, Queen's Veterinary School Hospital, University of Cambridge, Cambridge, UK.|Nuffield Department of Medicine, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK.
L J
http://orcid.org/0000-0002-1920-0817
LJ
Davison
Department of Pathology and Pathogen Biology, Royal Veterinary College, Hatfield, UK.
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A
Holder
Department of Pathology and Pathogen Biology, Royal Veterinary College, Hatfield, UK.
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B
Catchpole
Nuffield Department of Medicine, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK.
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CA
O'Callaghan
D000818:Animals; D016022:Case-Control Studies; D003920:Diabetes Mellitus / Q000235:genetics / Q000662:veterinary*; D004283:Dog Diseases / Q000235:genetics*; D004285:Dogs; D005260:Female; D017353:Gene Deletion; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D008297:Male; D009765:Obesity / Q000235:genetics / Q000662:veterinary*; D016133:Polymerase Chain Reaction / Q000379:methods; D011333:Pro-Opiomelanocortin / Q000235:genetics*
D011333:Pro-Opiomelanocortin
Endocrinology; Genetics; Pancreas; Polymerase chain reaction