Cloning Cats: Rainbow and CC Prove That Cloning Won’t Resurrect Your Pet

14 | Posted:


By Dr Sophia Yin


Even with the most recent advances in veterinary medicine, your beloved cat won’t live forever, but is the next best thing just around the corner? Will it someday be possible to resurrect your cat with cloning?

Nearly a decade ago, on December 22, 2001, scientists at Texas A&M University announced the birth of CC, the world’s first cloned cat. CC, as in Copy Cat, has the same DNA blueprint as her genetic mother, Rainbow. So, like identical twins they share the same genetic code. That means everything’s the same—their looks, their mannerisms, their…. But wait.

Although Rainbow and her clone, CC, have identical genes, Rainbow is calico in color while CC is a tiger tabby and has no orange


A closer view in color reveals they don’t actually look identical. In fact, technically they’re not even the same color. Rainbow, with her spackling of orange mixed in with patches of black accentuated by a white belly and legs is calico while CC, who has no orange coloring at all, is a tiger-tabby. Is CC really a clone or is this another example of what some scientists call the Jurassic phenomenon?

Dr. Leslie Lyons, an associate professor of genetics at the UC Davis School of Veterinary Medicine was the first person with the answer back in 2001. “Texas A&M sent us samples blind to see whether the cells lines were identical,” says Lyons. “We were called upon because we have a large genetic database on the domestic cat.”

Lyons wasn’t told the cells were from a cloning project, but she promptly determined that the cell lines were identical and in doing so she confirmed that CC was indeed a clone of Rainbow (only CC is a clone).

Why Does This Clone Look Different

So why the difference in appearance? “The cool thing about CC,” said Lyons in that early interview, “is that it shows that even though two animals are genetically identical, they may not look or act identical. A clone is never actually identical because there are so many different environmental factors that come into play.”

The most obvious disparity here is coat color. The orange coat color gene in cats is peculiar in that it is randomly inactivated in some clusters of skin cells and activated in others. When activated, the skin cells produce orange fur and when inactivated they produce black fur. This process usually results in a mosaic of orange and black. In CC, the orange color gene was inactivated in all of the skin cells—thus no orange in her coat. 

The white spotting pattern, which gives Rainbow and CC large white areas is also random. During fetal development, melanocytes, the pigment-producing cells in the skin, migrate across the skin starting from the back and racing towards the belly. If the melanocytes get a late start on their migration, they pull up short leaving the cat with flashy white ornamentation primarily on the underside and legs. This mechanism for expression of the white spotting gene means that even clones of say a simple black and white Sylvester-type cat would sport tuxedos with noticeable variations.

Even clones of a simple black and white Sylvester-type cat would sport tuxedos with noticeable variations.


Of course the other clear physical difference between Rainbow and CC that you may have noticed in the photos is that Rainbow is a little tubby, and CC is trim and sleek. Exercise and nutrition also have a major effect on how individuals look.

Behavioral Differences May Be Even More Pronounced

It’s now almost ten years later, but even early on it was clear that physical appearance was just the start of the differences seen between Rainbow and CC. Personality is where one might expect the largest gaps to emerge, since a myriad of factors dramatically alter behavioral development. These influences start in the womb with factors as simple as nutrition. Kittens of undernourished mothers develop brain deficits leading to developmental delays in crawling, suckling, eye-opening, climbing, playing and predatory behavior. By four months these kittens show stunted learning ability and abnormal levels of fear and aggression.

Even within the same maternal environment, kittens can develop differently. Females born nestled between two males within the womb experience a testosterone bath which leads to masculinization of their brains. In dogs, where this effect has been studied, such females turn tomboy. Some lift their legs to urinate and develop a strong desire to sniff everything in their environment. 

Once the youngsters are born, their environment becomes even more diverse and differences can quickly be amplified. As expected, social contact with the mother during the first four weeks is essential not just to survival, but also to normal emotional development. Those lacking this contact are unusually fearful of other cats and people and they exhibit randomly directed locomotor behavior. They’re also slow in the thinking department and show difficulty learning even simple associations such as the location of food sources. 

Luckily some of these changes can be offset by early human handling. Early handling is also essential in prepping cats for life with humans. Kittens handled regularly as little as five minutes from birth to 45 days are friendlier to unfamiliar people and investigate new objects more readily than those that are not handled. This explains why feral cats that spend their early weeks hidden from humans are difficult to tame whereas those captured and raised with people early on make an easy transition to normal household life.

Even at several months of age, the difference in personality between CC and Rainbow were clear. Rainbow was reserved. CC had been handled a lot early on and was curious and outgoing. Her outgoing nature continues even now at 10 years of age. She was adopted by Duane Kraemer, a Texas A&M professor of veterinary medicine who helped clone her and who has been taking care of her since. She lives in a two-story cat mansion that overlooks the Kraemer residence. She had three kittens in 2006 the “natural way,” with her somewhat shyer mate, Smokey. According to the Kraemers, CC was a good mother. Both she and her offspring are neutered now since the mating was to determine whether a cloned domestic cat can reproduce.

Cloning Will Not Resurrect Your Pet

Texas A&M no longer works with the pet cloning company, Genetic Savings and Clone, that funded the research for CC. Consequently, your chances of ever having your pet cloned are slim. But even if the technology were available, the take home message with CC is that cloning will not resurrect your pet. Instead, you would be more likely to get something that looked similar to your beloved pet but that acted quite differently, or your clone could even end up looking like a complete stranger. Now that would be a dream, turned nightmare!



Tags: , , , , , ,

14 responses to “Cloning Cats: Rainbow and CC Prove That Cloning Won’t Resurrect Your Pet

  1. This is a fascinating article. There’s been a lot of talk of cloning in the horse world for former superstars along the lines of the late Gem Twist.

    In fact, I believe 2-3 GT clones are already on the ground, as well as clones of several other superstar equine athletes across all disciplines.

    What a shame for the individuals, consortium and others involved to waste so much money trying to clone a former superstar instead of investing in potential superstars.

    But it is still nice to know we’ll be seeing new talents and not endless clones off success former animal star athletes! This can be true from the breed ring with dogs, show cats and any other sports where animals compete.

  2. Although it wouldnt be an identical twin, it would still be a wonderful way to reproduce a genetic line from an animal that may otherwise be subject to complete termination because the pet had been sterilized & then unexpectedly died or dissappeared! To me this would be like the second best alternative to breeding that would otherwise be impossible. At least its possible to be able to have a pet related to the one lost, due to this wonderful knowledge of cloning. At least, they could still in a way, “live on.” Family matters!! Ultimately, it would end up being better bc to me it would be hard knowing this wasn’t, in fact, THE pet originally lost!

    1. Cloning is unethical, period. If you take a five year old pet (or human, or any living organism for that matter) and clone it, that clone is genetically five years old at “conception”. It is this reason that clones “age” so much faster than their “sibling”.
      Mother Nature perfected natural selection, who are we to tamper with Her delicate balance? Better use of science would be disease irradiation, and perfecting cryogenic techniques, and making the technology accessible to the masses.

      1. Literally nothing stated in this is true.

        It comes from a myth since dolly the sheep died middle aged and had arthritis. People just made the assumption that dolly must have “aged fast” because of cloning.

        Turns out she was just not eating a proper diet. They made more clones of the same sheep. Some were allowed to gorge and got the same issues dolly did at the same points in life. Others weren’t and lived just fine. Some gorged for a while then were put on a diet…they developed the issues, but once dieting became healthy again.

        Turns out dolly was just a fat sheep that had bad health due to diet.

        Also, natural selection is neither delicate nor balanced…that’s why it works so well. You suck at life, then you die a virgin. That’s almost literally what natural selection is, and it’s hard to get less delicate than that.

        1. Agreed to the above post though the complete story of Dolly can be found here

          To set the record straight, Dolly was put down after being diagnosed with sheep pulmonary adenomatosis, a disease which had already taken 2 of the other sheep clones produced.

          Since the commercialization of somatic cell nuclear transfer “cloning” has produced thousands of healthy animals including cats, dogs, sheep, and by my own hand, mice, cows and horses. The initial risks which were observed in 2000 with the birth of larger bovine calves has been addressed and embryo development, pregnancy and live birth rates have also increased exponentally since that time. That being said, research still needs to be done in all areas of embryo production to improve these results.

          Cloning is a tool used to save valuable genetics, rescue reproductive capacity of older or castrated animals and will be used as a means for next generation advanced breeding technologies in bovine and equine. There are many uses of cloning technology which can help producers to improve genetic advancement.

          Commercial cat cloning is currently available through Viagen ( and is in development at InVitro Clonagem Animal, based in Mogi Mirim, São Paulo state Brazil. We hope to be able to offer these services in 1-2 years.

          You can contact me directly if you have more questions regarding cloning technology.

          (marc dot maserati at invitroclonagem dot com dot br)

        2. I disagree with both of you. You need to be careful what sites you chose to take your information from online. Especially when using a “.com” site for a scientific topic. Even using Dolly the sheep as a reference for your opinion isn’t very reputable, considering that she was the first cloned mammal and because of that information regarding her cloning is extremely outdated compared to recent advancements in reproductive cloning. I agree with the fact that it possible, but I also agree with the opinion that it is unethical. I don’t think that stating your opinion is bad as long as you know what you are talking about and have the facts to support it.

  3. As the article states, cloning is complex and a large number of factors influence the way in which genes are expressed–such that identical genetics alone will not create identical animals.

    But the business is far from a dead issue, and there are companies which clone both pets and livestock to preserve the genetics.

    And the interest has not died down over the years, and given the advances in genetic engineering tools over the past few years, interest in cloning and repairing genetic damage or flaws will likely continue indefinitely.

  4. I wonder if cloning solid pattern cats or dogs leads to animals that appear to be more of a match. I also wonder about temperament and intelligence of the clone. The nature versus nurture for lower animals like cats and dogs is probably less than humans since they are more instinctual creatures.

  5. For one, there are so many cats and dogs waiting to be adopted or dying on the streets…. Do we really need to clone more because someone can’t let go of thier pet?

  6. Cloning animals is not unethical. It is an amazing tool of science and may serve us well in the future. The bottom line is every animal is different and special, cloned or not. It is hard to move on when you have lost that special little being, since cats live at best a little less than 1/4 of our human lives. When you are heartbroken from loss – no one can heal your heart and it would seem tempting. While it sounds amazing to have a clone of your beloved friend, it is important to realize even a clone would act differently and may even look drastically different.

    The money and time spent cloning sadly could help a huge number deserving cats, or dogs that are already alive, aware, and suffering on this planet, and perhaps facing euthanasia simply because they are unwanted.

    The real tragedy may be that a new and also special little being will never have a chance to become just that- and we as loving individuals will miss out on that special relationship. No one can take away the love and memories we have for our pet in the past, or diminish how special they were. But now in the present, euthanizing an innocent kitten who never had a chance while 25- 30k is spent to try and bring back a beloved pet that will never be the past pet – that seems unethical and does no more to honor your past pet then helping another desperate would.

Leave a Reply

Your email address will not be published. Required fields are marked *