Research:

BACKGROUND. The development and characterization of the cat as a model of human hereditary disease is one focus of the Animal Genetics section of the LGD. The cat serves as an animal model for well over 40 human hereditary diseases, including many for which there is no rodent model. The availability of an appropriate animal model often is crucial in understanding the molecular mechanisms underlying a disease process. Ultimately, an animal model provides a whole animal system for trial of potential treatments. A genetic recombination map of highly polymorphic markers (Type II), integrated with a genetic recombination map of coding loci (Type I markers) will provide a valuable resource to establish the genetic basis for homology of feline disease pathology to human hereditary disease utilizing a directed linkage approach. 

Development of a Genetic Recombination Map of Microsatellite Loci in the Domestic Cat. Approximately two hundred seventy five primer pairs have been designed to amplify (dC.dA)n.(dG.dT)n dinucleotide repeat loci isolated and characterized from genomic DNA of the domestic cat. Individual loci are amplified in a 110 member three generation interspecies backcross pedigree between the domestic cat and the Asian leopard cat (Prionailurus bengalensis ). Fluorescently labeled products are genotyped in multiplex analysis with an Applied Biosystems 373A DNA Sequencer and software applications. At present 78 loci have been assembled in 25 linkage groups; two linkage groups are physically assigned. 

Conservation of Domestic Cat Microsatellite loci in exotic cat species: The Animal Genetics section has an interest in the evolution of genetic factors associated with host resistance and pathology in natural populations.

Development of a Feline Microsatellite Panel for genetic individualization and forensic applications: A group of ten dinucelotide repeat loci has been selected for genetic individualization of domestic cat hairs for forensic analyses. A Òmatch windowÓ or measurement precision estimate was empirically established for each locus by determining the maximum gel migration difference among alleles identical by descent in different individuals of a 3-generation pedigree. Hardy-Weinberg equilibrium and abundant heterozygosity was observed for each locus in cat population samples from Canada and the USA. The probabilities of two unrelated individuals matching by chance (Pm) at all ten loci was estimated as 1.35 x 10-10. The system has been evaluated using blinded samples in a proficiency test and utilized to generate matching composite genotypes of a cat hair linked to a homicide case and that of the pet cat of the primary suspect. 

Dr. Raymond is currently utilizing markers she has developed in a broad range of applications including genetic linkage mapping in feline models of human hereditary disease, the design and implementation of the first animal forensic typing system and in the conservation genetics of endangered species.

Last Updated on August 30, 2001 by Shawn Palmer