What Happens When You Clone a Clone? So Far, Adorable Puppies

You know how if you make a copy of a copy, it's sometimes not as sharp as the original? Scientists wondered if that principle, which works on documents and Michael Keatons, would hold true of clones in the real world. That's why they made a set of clones out of Snuppy, the world's first cloned dog. And so far, the pups are doing just fine.

The three surviving reclones at 2 month of age. They were dervived by SCNT of adipose-derived mesenchymal stem cells (ASCs) taken from Snuppy at five years of age.

Copying a Copy

A clone is a perfect copy. So if you make a perfect copy of a perfect copy, you should get something exactly like the original, right? That all seems to make sense, but as cloning technology develops, it's important to make absolutely sure. After all, there were some early missteps. Although first-ever adult mammal clone Dolly the sheep's short lifespan was found to be a fluke unrelated to her cloning, the fact that the first mammal cloned from an adult seemed to age twice as fast as her progenitor is enough to give even the maddest scientist second thoughts.

These days, we've had enough successful clones (including Dolly's many "sisters") to feel pretty confident that cloning is perfectly viable. But until about a year ago, nobody had ever tried to make a clone of a clone. Enter Snuppy. (His name is a portmanteau of "puppy" and "Seoul National University"). Cloned from an Afghan hound named Tai in 2005, Snuppy lived to 10 — a bit under the average lifespan of the breed, but not outside of the normal range. But what about Snuppy's genes?

A year after cells from Snuppy were grown into a new generation of clones, three of the four puppies are doing just fine (the fourth, sadly, died shortly after birth for reasons unrelated to the cloning). Now, it's a matter of seeing how they grow up. Speaking with Gizmodo, study author CheMyong J. Ko said the puppies will be closely monitored to see how their genetics, immune systems, and behaviors differ from each other, from Snuppy, and from Tai. Additionally, each puppy will find his forever home with a different family in order to see how environment affects their physical wellbeing.

A Dog-Clone-Dog World

Seeing as how mammals had been cloned well before Snuppy ever came into existence (and clones of other animals such as amphibians date back to the 1950s), it might not seem like a dog clone is such a big deal. But it is. See, dog reproduction is actually very weird, and it's weird in all of the ways that make manipulating it harder. Scientists weren't even able to achieve in-vitro fertilization of a dog until 2015 — the first human born this way was Louise Brown, born in 1978. For one thing, dogs only come into heat once or twice a year, making timing a major issue for geneticists. But there's another wrinkle on top of that one: unlike virtually every other mammal, an ovulating dog doesn't produce a viable egg right away. Instead, her eggs need a day or two to mature in the oviducts, adding yet another element of uncertainty.

What else could we use cloning for? How about bringing back Pleistocene species? Check out Beth Shapiro's "How to Clone a Mammoth" to find out exactly how that would work. We handpick reading recommendations we think you may like. If you choose to make a purchase through that link, Curiosity will get a share of the sale.

The Science Behind Dog Cloning

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Key Facts In This Video

  1. The company Sooam has cloned more than 600 dogs of various breeds. 01:09

  2. To clone a dog, Sooam needs an egg donor dog as well as a surrogate mother. 03:16

  3. Although cloned puppies can appear identical to the original dog, their personalities are shaped by the environment and other factors. 06:49

Written by Reuben Westmaas December 20, 2017