The first clone of a pet-type animal--a kitten named Cc:--has been unveiled by scientists at Texas A&M University in College Station. In the 21 February issue of Nature they describe their epochal accomplishment, which is a step toward the more difficult goal of cloning a dog. The scientists' work is part of a project sponsored by wealthy Phoenix businessperson John Sperling, who wants to be able to replace his husky-border collie mix, Missy, when her time is up.
Cc: is the product of the predictably named Operation Copy Cat, which started only a year ago. The researchers' first attempt ended in failure. The team, headed by Mark Westhusin, removed the nuclei of cells from the lining of a cat's cheek and inserted them into enucleated cat eggs. Although 82 cloned embryos were implanted into surrogate mother cats, only one pregnancy resulted and the fetus died. In their next try, the scientists used nuclei from the cumulus cells surrounding the ova. This time, it only took five embryo implantations to achieve a successful pregnancy. The success rate--1 out of 87 implanted embryos--is comparable to the success rate in sheep, mice, cows, goats, and pigs, the researchers report. They say Cc: is a lively, normal-looking kitten.
The cat work is only a preliminary step in the Missyplicity Project, the initiative Sperling launched 5 years ago. So far, he has put $3.7 million into the Texas group's cloning efforts. Westhusin explains, however, that dog clones are still a long way off. Dogs are much tougher to clone, he says, because they come into heat and produce eggs much less frequently. Moreover, dogs' eggs won't mature in a test tube, he says, so the focus in this area is still on "how do you get viable ova."