CC, for "CopyCat" or "Carbon Copy" (born December 22, 2001), is a brown tabby and white domestic shorthair and the first cloned pet. CC's surrogate mother was a tabby, but her genetic donor, Rainbow, was a calico domestic shorthair. The difference in hair coloration between CC and Rainbow is due to epigenetic re-programming, which normally occurs in a fertilised embryo before implantation.
As a result of the cloning process, X inactivation occurred in the same X chromosome in all of CC's somatic cells, instead of the usual mosiacism that gives calicos their distinctive coloration. CC is genetically identical to Rainbow but epigenetically and thus phenotypically different. The embryo that became CC was the only one of 87 embryos produced in this research project that developed into a full-term pregnancy after being transferred to surrogate mothers.
The research project that produced CC was known as "Operation CopyCat," and was part of a larger project (called Missyplicity) to clone a dog named Missy. Genetic Savings & Clone, which provided commercial gene banking and cloning services to pet owners and which closed in 2006, funded the research.
CC was born at the College of Veterinary Medicine at Texas A&M University, under the direction of Dr. Mark Westhusin, in collaboration with Dr. Taeyoung Shin. Her existence was announced publicly on February 14, 2002, in conjunction with the publication by the scientific journal Nature of a paper about the accomplishment.
CC now lives in the household of Dr. Duane Kraemer, one of the scientists who worked on the project.
In September 2006, CC gave birth to three kittens who were fathered naturally. This is the first time a cloned pet has given birth. CC appears to be free of the cloning-related health problems that have arisen in some other animal clones. "CC has always been a perfectly normal cat and her kittens are just that way, too," says Kraemer. "We’ve been monitoring their health and all of them are fine, just like CC has been for the past five years."