The Labrador Retriever as a Model of Naturally Occurring Myopia: Genetic and Environmental Contributions

Aims: To validate the dog as an animal model of naturally occurring myopia by identifying genetic and environmental factors which are associated with myopia development in the Labrador Retriever. Methods: A large pedigree of Labrador Retrievers was phenotyped for refractive error. Using statistical (familial aggregation) analysis, refractive error data was used to investigate the inheritance of the trait within the pedigree. DNA samples were taken for later analysis. Potential environmental factors early in life were also studied in relation to adult refractive error; including birth weight, growth rate, season of birth, ocular pathology and litter size. DNA samples were extracted and a pilot genetic association study was designed to identify genetic loci for canine refractive error using a genome wide SNP array with a myopic case group and a non-myopic control group. Results: A significant prevalence (37%) of myopia was found within the pedigree studied. Familial aggregation analysis demonstrated a significant genetic contribution, as well as showing a strong environmental contribution. Heritability of refractive error was 0.506. Smaller litters were shown to have significantly higher levels of myopia. No association was found between any environmental factors and adult refractive error, apart from season of birth in one age tertile. A genetic pilot study was designed to test for genetic loci which contribute to canine refractive error. Conclusions: The Labrador Retriever is potentially an ideal animal model for the study of human myopia; the condition is naturally occurring in dogs, develops in a significant proportion of the population and can be phenotyped noninvasively. This study is the first to demonstrate the inheritance of myopia in any animal other than humans. The dog genome allows for myopia to be studied at a molecular level and due to the domesticated nature of the dog, breeding and environmental manipulations can also be conducted to identify further aspects of myopia causatio

Name thesis:degree_name

PhD

Level thesis:degree_level

Doctoral

Grantor dc:publisher

ResearchSpace@Auckland

Year dc:date.issued

2010

Author dc:creator

• Black, Joanna

Statement dc:rights

• Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Licence dc:rights.uri

• https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm

Handle dc:identifier.uri

https://hdl.handle.net/2292/5847

OAI identifier oai:identifier

oai:researchspace.auckland.ac.nz:2292/5847