The Magazine

It Didn't Start with Dolly

From the May 2, 2005 issue: Human cloning is closer than you think.

May 2, 2005, Vol. 10, No. 31 • By WESLEY J. SMITH
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HERE'S AN EASY POP QUIZ: What's the name of the first cloned mammal? If you answered, "Dolly," that would be . . . wrong.

Wrong? But wasn't Dolly the sheep touted by the media as the first mammal ever made "asexually" through the cell nuclear transfer cloning process? Yes, but there are a lot of things you hear from the scientific/media establishment that are not exactly accurate.

The first cloned mammals to be brought into being "asexually" via cell nuclear transfer cloning and gestated through birth were lambs born nearly two years before Dolly. As reported by Ian Wilmut and his team in the March 7, 1996, Nature, they took the cell nuclei out of sheep embryo cells, placed each into a sheep egg that had had its own nucleus removed, fused them, and thereby generated cloned sheep embryos.

Wilmut's team then implanted their embryos into ewes, resulting in five live births. Two lambs survived. The scientists announced this breakthrough as follows: "Here we provide the first report . . . of live mammalian offspring following nuclear transfer from an established cell line." Wilmut explicitly identified the lambs as "cloned."

The only difference between these earlier cloned sheep and Dolly was that the first lambs were made asexually using cells taken from sheep embryos, while Dolly was made asexually from a cell taken from an adult ewe. But the cell nuclear transfer cloning process in both experiments was the same. Indeed, in their famous February 27, 1997, announcement of Dolly, Wilmut and his team stated that the "first offspring" to be "born after nuclear transfer" had been achieved previously.

Why is this of interest? Because, the same line of experiments that culminated in the birth of Dolly is already well under way with primates. Which means human cloning is closer to reality than most people realize.

Efforts to ban human cloning are commonly greeted with sighs of exasperation from the big biotech spin machine. Yes, the scientists and their flacks say, sheep have been cloned to birth. So, too, have cats, pigs, and mice. But not primates, the closest genetic relatives to man. This means that human reproductive cloning will almost surely never work. Thus, bioethics spokesman-in-chief Arthur Caplan stated in a 2003 article published on MSNBC.com:

Despite a lot of effort, no one has managed to clone an adult monkey or any other primate. Nearly all experts on primate cloning believe that monkeys and human beings will never be cloned because the biology of primate reproduction is simply unlike that of cats, goats, sheep and mice.

This argument is resorted to with increasing frequency by scientists testifying before legislative bodies in favor of explicitly legalizing human therapeutic cloning (creating cloned embryos to be destroyed in medical research or treatments). Their point is that since biological barriers seem to prevent cloned embryos from surviving to birth, these "products of nuclear transfer" lack basic human potential and therefore should not be considered a form of human life. And if they are not human life, there are no moral or ethical reasons to oppose therapeutic cloning.

Tell this to legislators with no background in the history of biotechnological research and it has a ring of plausibility. They may not know that ten years ago most scientists believed all mammalian cloning was impossible. But that point aside, the assertion that reproductive cloning in primates cannot be done is just plain wrong. Indeed, it has already been accomplished.

The first two cloned primate births were reported in a 1997 article entitled, "Rhesus Monkeys Produced by Nuclear Transfer," published in the peer-reviewed journal Biology of Reproduction. They were cute, too. The article included a picture of the cloned monkey babies (named Ditto and Neti) hugging each other, with the caption: "Rhesus monkey infants produced by nuclear transfer." A genetic analysis of the infants "provided definite proof of the success of nuclear transfer technology." So much for the impossibility of primate reproductive cloning.

Cloning advocates will no doubt retort that the monkey babies were manufactured using not adult monkey cells but the nuclei of cells extracted from monkey embryos. This is true, but so what? It is indisputable that these cloned monkey babies were created asexually--that is, through cell nuclear transfer technology--just as the first cloned lambs brought to birth by Ian Wilmut were created asexually using cells from sheep embryos.