Scientists from Oregon Health and Science University reported on Wednesday in the scientific journal Cell that they had created embryonic stem cells from a cloned human embryo. This is the first time that human stem cells have been produced using nuclear transfer, a cloning technique in which the nucleus of one person’s cell is transferred into an egg that has had its nucleus removed. The technique could be used to create patient-specific human embryonic stem cells, which could be used to study genetic diseases, aid drug development, and for therapeutic transplantation back into a patient.
Patient-specific stem cells can also be created by “deprogramming” adult cells such as skin cells into a stem-cell state (see “Medicine’s New Toolbox”). The resulting induced pluripotent stem cells are widely used by researchers. But some studies suggest that genetic and molecular abnormalities may be more common in the induced pluripotent stem cells than in cloned embryonic stem cells and it’s not yet clear how well induced pluripotent stem cells will be at creating the diversity of cell types in the human body.
In the Wednesday report, Shoukhrat Mitalipov and colleagues write that past attempts at creating cloned embryonic stem cells were troubled by developmental arrests in the embryos created by nuclear transfer. According to Nature,the investigators tested and tweaked cloning techniques on “more than 1,000 monkey eggs before moving on to human cells” and finding the right combination of methods.
The resulting technique makes use of the outer covering of a virus that triggers cell fusion, an electric pulse to activate development of the egg-nucleus hybrid, and a bit of caffeine to steady embryonic development. The researchers used the cloned embryonic stem cells to produce different cell types, including heart cells capable of beating. The embryos described in the paper were grown for a maximum of seven days.
Some may worry that scientists can now clone humans, but according to an OHSU release, Mitalipov has tried for several years to produce a monkey from nuclear-transfer embryos without success. As reported by National Public Radio: “The procedures we developed actually are very efficient to make stem cells, but it’s unlikely that this will be very useful for kind of reproductive cloning,” Mitalipov says.
Susan Young RojahnBiomedicine Editor
I’m the biomedicine editor for MIT Technology Review. I look for stories where technology stands to improve human health or advance our understanding of the human condition.
I joined MIT Technology Review in March 2012 after… More a brief stint in the Washington, D.C., news bureau of the scientific journal Nature. Before I ventured to the East Coast, I spent several years in the San Francisco Bay Area as a doctoral student in molecular biology and one whirlwind year in science-writing boot camp in Santa Cruz.
In California, I wrote for the Stanford University press offices, the Multiple Sclerosis Discovery Forum, and the Salinas Californian newspaper. I grew up in a small town in eastern Texas, surrounded by bird song, rolling cattle fields, and lanky pine trees. When I’m not exploring health tech, you will probably find me cooking or giggling over an exceptional LOLcat.
Identical long-tailed macaques Zhong Zhong and Hua Hua were born eight and six weeks ago at a laboratory in China.
Dolly the sheep was created 20 years ago and was the first animal to be cloned.
And the success of the monkey cloning marks a watershed in cloning research and raises major ethical questions.
But the cloning of monkeys will be seen by some as a step too far towards the eventual creation of tailor-made humans.
PAWorld’s first monkeys CLONED - and the technology could lead to DESIGNER humans
First photos of the world’s first CLONED monkeysWed, January 24, 2018
Two long-tailed macaques monkeys who are the first primates to be cloned using transferred DNA. Identical long-tailed macaques Zhong Zhong and Hua Hua were born eight and six weeks ago, respectively, at a laboratory in China
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This handout picture from the Chinese Ac
PAThe monkeys were born eight and six weeks ago at a laboratory in China.
Scientists behind the project say the moneys were cloned as a way of producing genetically engineered primates that can be used for testing to help eradicate diseases, but critics suggest it is simply a stepping stone to creating tailor made humans.
The Chinese team led by Dr Qiang Sun, director of the Non-Human Primate Research Facility at the Chinese Academy of Sciences Institute of Neuroscience, Shanghai, made the breakthrough using DNA from foetal connective tissue cells.
After the DNA was transferred to eggs that were donated, the scientists genetically reprogrammed them to alter genes that would have suppressed embryo development.
Zhong Zhong and Hua Hua were the result of 79 nuclear transfer attempts. Two other monkeys were initially cloned from a different type of adult cell, but failed to survive.
PA"There was much failure before we found a way to successfully clone a monkey."
Dr Sun said: "We tried several different methods, but only one worked. There was much failure before we found a way to successfully clone a monkey.
He said: "You can produce cloned monkeys with the same genetic background except the gene you manipulated.
“This will generate real models not just for genetically based brain diseases, but also cancer, immune or metabolic disorders and allow us to test the efficacy of the drugs for these conditions before clinical use."
The scientists insisted they followed strict international guidelines for animal research, set by the US National Institutes of Health.
GETTYDolly the Sheep was created 20 years ago
Co-author Dr Muming Poo, another member of the Chinese Academy of Sciences team, said: "We are very aware that future research using non-human primates anywhere in the world depends on scientists following very strict ethical standards.”
British cloning expert Professor Robin Lovell-Badge, from The Francis Crick Institute in London, moved to squash fears that this could lead to human cloning.
Prof Lovell-Badge said: "The work in this paper is not a stepping-stone to establishing methods for obtaining live-born human clones.
"This clearly remains a very foolish thing to attempt. It would be far too inefficient, far too unsafe, and it is also pointless.
“Clones may be genetically identical, but we are far from only being a product of our genes."
Dolly made history 20 years ago after being cloned at the Roslin Institute in Edinburgh.
It was the first time scientists had managed to clone a mammal from an adult cell, taken from the udder of a Finn Dorset sheep.
Since then many other mammals have been cloned using the same single cell nuclear transfer (SCNT) technique, which involves transferring cell nucleus DNA to a donated egg cell that is then prompted to develop into an embryo.
They include sheep, cattle, pigs, dogs, cats, mice and rats - but until now, there has never been an SCNT-cloned monkey.