Cats have been domesticated for approximately 5,000 years, yet little is known about their past. Due to the importance of the cat in ancient Egypt it is often assumed that cats were domesticated in Egypt from the African wildcat, Felis sylvestris lybica. This assumption, however, has not been substantiated by any genetic studies. Another aspect that has not been previously explored is the relationship of the different cat breeds to other breeds as well as to the different subspecies of Felis sylvestris. There are nearly 50 cat breeds recognized today. Of those 50, 15 are foundation breeds, or breeds that are thought to have arisen naturally due to geographic isolation and adaptation to their habitat. Very little is known about the population genetics of cat breeds.

In order to clarify the relationships between cat breeds and gather valuable genetic data, we have surveyed 20 cat breeds, 3 feral populations, and 2 wildcat subspecies using 30 feline-derived microsatellite markers. Purebred cat samples were obtained at cat shows and from breeders, with great care taken to sample those cats that will contribute to future generations. At least 30 cats from each breed or population were genotyped to ensure accurate sampling of the populations. The resulting data was analyzed using several software programs including Whichloci, Genepop, and Popgene.

Preliminary results indicate a significant reduction in genetic diversity of several cat breeds. Genetic diversity was approximated using two measures-the polymorphism information content (PIC) and heterozygosity. Breeds such as Birman, Russian Blue, and Havana Brown show marked decrease in genetic diversity as compared to random bred cats, and especially when compared to the African wildcat. The practicality of breed assignment was tested using the program Whichloci with very promising results. An unknown cat can be assigned to its correct breed using only 6 microsatellite markers when 5 breeds are considered.

The data obtained in this study can be used as a valuable tool for cat breeders in the development and management of cat breeds. It also has applications for forensics as well as SNP based disease association studies. This data may also be used to clarify the domestication of the cat.