Monkey See, Human Do: Cloning Macaque Monkeys with Fetal Cells


Craig Klugman

Publish date

Tag(s): Legacy post
Topic(s): Animal Ethics Clinical Trials & Studies Research Ethics Science

by Craig Klugman, Ph.D.

How afraid of human cloning should we be?”
Monkeys have been cloned, Paving the way for human cloning
Yes, They’ve Cloned Monkeys in China. That’s Doesn’t Mean You’re Next
Scientists clone monkeys, leapfrog closer to humans
Monkeys cloned using same technique behind Dolly the sheep

News headlines have declared the success of a Chinese research team in birthing two cloned macaque monkeys. The research is in the February 8 issue of Cell and marks the first time that a nonhuman primate clone has been born. The macaques were created by somatic cell nuclear transfer (SCNT), the same method used in the cloning of Dolly the Cloned Sheep in 1996 and in 23 mammal species since then. However, to make the procedure work in the macaques, the scientists had to use the nucleus not of an adult cell but of a fetal cell, as well as injecting epigenetic modulators into the developing fetuses.

Art by Craig Klugman

The Chinese team created 301 embryos. In one arm of the study, adult cells were used to create 192 embryos, 181 of them were transferred to 42 surrogates. There were 22 pregnancies and 2 births, but they died quickly. In the second arm, fetal cells were used to create 109 embryos; 79 of the embryos were implanted into 21 surrogates. Six pregnancies took hold and there were two live births: Zhong Zhong and Hua Hua (based on the word Zhonghua, meaning “Chinese nation”). As of this week, the babies are 7 weeks old. The overall success rate is thus 0.66%.

As the headlines at the beginning of this article show, the news media have written varied responses to this announcement. Some have talked about how this step brings science closer to human cloning, and others have downplayed the potential for human cloning by not mentioning the possibility or suggesting that human cloning is unlikely.

Back in 1997, I wrote my bioethics master’s thesis on the history of the cloning debate from the late 1800s through Dolly. Among the major concerns discussed in regards to human cloning is making copies of people and the change in what is means to be human if cloning is possible (e.g. do clones have a soul?). Because the primate technique can only be done using nuclei from fetal cells, the first concern is vacated: We will not be able to clone born people. Although, it is conceivable that a parent could have fetal cells frozen for the possible future cloning of a child (Dolly’s transferred nuclei were taken from frozen udder cells).

The scientists suggest that the benefit to cloning primates is the ability to do research on genetically similar animals. By having the same genotype, one testing variable can be controlled. In the United States. alone, about 70,000 nonhuman primates are being used in research. However, at least in the US, primate research may be headed toward a ban. The NIH no longer conducts research on chimpanzees and there have been calls for limiting research with other primates as well. In 2016, the NIH led a review regarding its policies about nonhuman primate research. Given the intelligence, rich emotional lives, and culture that have been found in many nonhuman primates, there is strong ethical concern that using them in research does not respect their dignity. However, no bans or limits have yet been initiated. Thus, if there is a move away from using primates in research, then the justification for this particular study may be unwarranted. The research team seems to have done this cloning simply to see if it could be done.

As for human cloning, there has been extensive debate since Dolly entered the world stage. A United Nations Declaration banning human cloning has been adopted. UNESCO established a working group to explore establishing a “legally binding” convention banning human cloning—a challenge since global governance remains elusive. The United States has also not made human cloning illegal. However, there are financial barriers to this possibility. Consider that cloning a cat costs $25,000 and a dog costs $50,000. A 2001 article ran the math and calculated that cloning a human would cost $1.7 million. Cloning a human is unlikely to be widely affordable.

Another barrier to human cloning is the harm principle: With a 0.66% success rate, almost 150 embryos would be unsuccessful to create a single live clone birth. Given that, at least in the U.S., there is consideration for potentiality in human embryos, this level of discard is unlikely to be widely accepted. Even if one views a human embryo as a cluster of cells, there is an emotional attachment that a human parent would have to its potential cloned progeny that makes acceptance of this rate unlikely.

If the value of cloning a nonhuman animal is for its productivity, our emotional attachment, or as research subjects, then the impetus does not apply to humans. Since we do not consume humans as food products or for racing, the eugenic arguments for cloning prized cattle or horses does not apply. In regards to research: human subjects research requires a review as well as consent and assent from the subject or subject’s guardian/parent. A potential future clone could not consent and a parent is unlikely to consent to have a small army created for research purposes. Thus, creating a clone army to do battle together (all the blood is compatible if a transfusion is needed), or to be created as sources of organ transplants for sick people (again, the technology only works with fetal cells, so parents would have to create clones during fetal development and keep one aside to be used as an organ farm) in impractical and highly unlikely. Emotional attachment would be cloning a deceased loved one, which this technology does not support (since it requires fetal cells and does not work on adult cells). Perhaps one might want to generate a new body for someone severely injured (which would require developing a way to transplant brains from body-to-body or to transfer brain patterns into another brain) but that technology is well beyond our current capabilities.

Thus, the risk of human cloning is still an idea of science fiction. Although this latest discovery may provide fodder for a new round of cloning horror and sci fi movies, it is unlikely to alter the real human landscape. However, it does suggest the need for further movement on international study and agreements on the future of human cloning.

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