Cat genetics describes the study of inheritance as it occurs in domestic cats. In feline husbandry it can predict established traits (
phenotypes) of the offspring of particular crosses. In
medical genetics, cat models are occasionally used to discover the function of homologous human disease genes.
The domesticated
cat and its closest wild ancestor are both
diploid organisms that possess 38
chromosomes[2] and roughly 20,000 genes.[3] About 250 heritable
genetic disorders have been identified in cats, many similar to human
inborn errors.[4] The high level of similarity among the
metabolisms of mammals allows many of these feline diseases to be diagnosed using
genetic tests that were originally developed for use in humans, as well as the use of cats in the study of the human diseases.[5][6]
An example of a
mutation that is shared among all felines, including the big cats, is a mutant
chemosensor in their
taste buds that prevents them from tasting sweetness, which may explain their indifference to fruits, berries, and other sugary foods.[7] In some breeds of cats
congenital sensorineural deafness is very common, with most
white cats (but not
albinos) being affected, particularly if they also have blue eyes.[1] The gene responsible for this defect is the
KIT gene and the disease is studied in the hope that it may shed light on the causes of hereditary deafness in humans.[8] Mutations in this gene also causes white spotting.[9]
Since a large variety of coat patterns exist within the various cat breeds, the cat is an excellent animal to study the
coat genetics of hair growth and coloration.[10] Several
genes interact to produce cats' hair color and coat patterns. Different combinations of these genes give different
phenotypes. For example, the
enzymetyrosinase is needed to produce the dark pigment
melanin and
Burmese cats have a mutant form that is only active at low temperatures, resulting in color appearing only on the cooler ears, tail and paws.[11] A completely inactive gene for tyrosinase is found in albino cats, which therefore lack all pigment.[12] Hair length is determined by the gene for
fibroblast growth factor 5, with inactive copies of this gene causing long hair.[13]
The Cat Genome Project, sponsored by the Laboratory of Genomic Diversity at the U.S.
National Cancer Institute Frederick Cancer Research and Development Center in
Frederick, Maryland, aims to help the development of the cat as an
animal model for human hereditary and
infectious diseases, as well as contributing to the understanding of the evolution of mammals.[6] This effort led to the publication in 2007 of an initial draft of the genome of an
Abyssinian cat called Cinnamon.[3] The existence of a draft genome has led to the discovery of several cat disease genes,[3] and even allowed the development of cat
genetic fingerprinting for use in
forensics.[14]
^Nie W, Wang J, O'Brien PC (2002). "The genome phylogeny of domestic cat, red panda and five mustelid species revealed by comparative chromosome painting and G-banding". Chromosome Res. 10 (3): 209–22.
doi:
10.1023/A:1015292005631.
PMID12067210.
S2CID9660694.
^Menotti-Raymond M, David VA, Stephens JC, Lyons LA, O'Brien SJ (1997). "Genetic individualization of domestic cats using feline STR loci for forensic applications". J. Forensic Sci. 42 (6): 1039–51.
doi:
10.1520/JFS14258J.
PMID9397545.