Calico cat

The calico cat is most commonly thought of as being 25% to 75% white with large orange and black patches; however, they may have other colors in their patterns.

A calico cat is not to be confused with a tortoiseshell, who has a black undercoat and a mostly mottled coat of black/red or blue/cream with relatively few to no white markings.

[1] Calicoes with diluted coloration (blue tortoiseshell and white) have been called calimanco or clouded tiger.

Male calicoes have an extra X chromosome (XXY, known as Klinefelter syndrome in humans)[7] or are genetic chimeras with two different sets of DNA (XX and XY).

[9] The proportion of cats having the orange mutant gene found in calicoes was traced to the port cities along the Mediterranean in Greece, France, Spain, and Italy, originating from Egypt.

[12] Printed calico was imported into the United States from Lancashire, England, in the 1780s, and a linguistic separation occurred there.

While Europe maintained the word calico for the fabric, in the US it was used to refer to the printed design or pattern.

[17] In 1961, Mary Lyon proposed the concept of X-inactivation: when one of the two X chromosomes inside a female mammal shuts off.

[22][23] All but approximately one in ten thousand of the rare calico or tortoiseshell male cats are sterile because of the chromosome abnormality and breeders reject any exceptions for stud purposes because they generally are of poor physical quality and fertility.

Even in the rare cases where a male calico is healthy and fertile, most cat registries will not accept them as show animals.

[24] As Sue Hubble stated in her book Shrinking the Cat: Genetic Engineering Before We Knew About Genes, The mutation that gives male cats a ginger-colored coat and females ginger, tortoiseshell, or calico coats produced a particularly telling map.

[25] The study of calico cats may have provided significant findings relating to physiological differences between female and male mammals.

[29] In the late nineteenth century, Eugene Field published "The Duel", a poem for children also known as "The Gingham Dog and the Calico Cat".