 |
Genetics 402: Natural Mutations
|
 |
Polydactyl cat |
Mutation is defined as changing, deleting or inserting a single base unit of DNA. It also means rearranging big sections of genes or chromosomes to result in variant forms that might show up in subsequent generations. For a mutation to be considered natural means that genetic scientists have not engineered it; it’s simply nature at work.
Numerous examples of natural mutations have occurred in cats over the years. Some mutations can be harmful to the cat’s physical well being. But when it’s a non-threatening physical characteristic, and, one that is in fact found attractive to the human eye, breeders and geneticists then step in and “select it.” Through a special breeding program, breeders can preserve this distinctive look for future generations. In doing so, they essentially create a new breed.
These physical characteristics are called a cat’s phenotype. Clearly physical natural mutations include a bobbed tail, short limbs, paws typified by six toes, folded ears, wired or curly coats and even a hairless appearance.
Tails
Examples of natural tail mutations include the Manx cat, one of the oldest cat breeds, which originated on the Isle of Man off the coast of England. Other breeds with unusual tails include the popular Japanese Bobtail and the American Ringtail, typified by a curly tail.
Scottish Fold cat |
Legs
The Munchkin cat’s short legs are also the result of a naturally occurring genetic mutation. The breed was first introduced to the American public at a cat show held in New York City’s Madison Square Garden by The International Cat Association (TICA) in 1991. It traces its roots back to the 1980s when a music teacher named Sandra Hochenedel found a pregnant cat, who she named Blackberry, that produced a litter with short-legged kittens. She gave one of the kittens, Toulouse, to a friend and cat fanciers claim that today’s breed descended from breeding those two cats.
Some believe the Munchkin could experience the same chronic body pains, like arthritis, as short-limbed dogs. Breeders maintain that cats’ flexible spines, however, prevent them from having similar conditions.
Paws
Polydactyl (six-toed) cats are common around the world and not linked directly to specific breeds. Ernest Hemingway is known to have owned many polydactyl felines at his home on Key West. The cats who still live at the Ernest Hemingway House are descendents.
Devon Rex cat |
Ears
The Scottish Fold has ears that fold forward. Former boxer George Forman is a huge fan of this breed. Scottish Fold cats became famous when author Peter Gethers traveled the world with his Scottish Fold named Norton and wrote several hilarious books about their adventures.
The ears on the American Curl cat curl backward. They are found in long- and shorthaired varieties.
Coat
Some coat types that result from natural mutations belong to the curly-coated Cornish Rex and Devon Rex Cats. Cornish Rex cats date back to the 1950s in England; the Devon Rex was first seen in Devon, England, in the 1960s.
The La Perm breed is hairless when young and then grows either a semi-longhaired or longhaired curly coat. A spontaneous mutation also causes the wired-haired coat of the American Wirehair cat.
Hairless cats have appeared in different parts of the world at different times. The breed known as the Sphynx descended from two lines of natural mutations, one bred in Minnesota and the other in Toronto, Canada. The hairless coat resembles a chamois in texture.
This breed received TV and movie coverage in the 1990s. The TV sitcom “Friends” featured a cat called Mrs. Whiskerson; Dr Evil, in the “Austin Powers” movie series, had a Sphynx sidekick called Mr. Bigglesworth.
Go back to class schedule and course materials>>
 Give us your opinion on
Genetics 402: Natural Mutations
|