The monkeys named Roku, Hex and Chimero are unique because normal animals have cells created by mixing genetic material derived from two parents (Hex, the Greek word for "six" is the name of a fire-breathing creature in Greek mythology made up of many animal parts).
This is the first time chimeric primates have been created. Scientists have successful created chimeric mice, rats, and rabbits in the past. AFP
reports that attempts to create chimeric primates have failed in the past, but scientists have modified the methods they used successfully in mice and rats. According to Shoukhrat Mitalipov, lead researcher at the Oregon National Primate Research Center
of the Oregon Health and Science University
, successful cultivation of primate mixed-embryos, unlike rodent's, require more potent, early stage cells from a living embryo. BBC
reports that the team, following the procedure for creating chimeric mice and rats, had used embryonic stem cells at a "pluripotent" stage of development (pluripotent cells can develop into any body tissue but cannot develop into whole organisms). So the researchers tried using "totipotent" cells from very early stage embryos (totipotent cells can develop into whole organisms, including placenta and other tissues).
reports that Prof. Robin Lovell-Badge of the UK National Institute for Medical Research in Mill Hill, said the research breakthrough was "very important". Lovell-Badge said: "Assumptions about the way human embryos develop have always been based on the mouse." He said this has been shown to be mistaken assumption. According to Lovell-Badge, researchers had for some time suspected that pluripotent stem cells from humans and monkeys were different from those in mice.
The successful creation of chimeric monkeys, of course, leads to the possibility of creating chimeric human beings in the future, a fact which explains why many are worried about the research work.
According to the researchers, after they had extracted cells from six rhesus embryos and combined them to make a single embryo cell, they implanted it into a surrogate mother. AFP
reports Mitalipov said: "The cells never fuse (unlike cells that form embryos in normal animals with two parents), but they stay together and work together to form tissues and organs. The possibilities for science are enormous."
The scientists are touting their achievement as major breakthrough for medical research, saying that it could help stem cell research. The scientists say that the monkeys are healthy and that their birth opens up new opportunities because of the close biological links of monkeys and human beings. The new technique, the researchers say, could help scientists learn more about IVF, contraception and growing human organs.
Many are already criticizing the work on ethical grounds and accuse the researchers of disregarding the welfare of the animals. Daily Mail
reports that the British Union for the Abolition of Vivisection (BUAV) has described the research as "deeply disturbing"
Jarrod Bailey, scientific consultant of BUAV, said: "Using such highly sentient animals in this research raises enormous ethical concerns and imposes a heavy welfare burden, resulting in severe suffering to many animals. As few genetically modified animals show the ‘desired’ characteristics, many will be killed even before any research can take place, while others will die of severe and unrelated malformations caused by the genetic modifications. The monkeys who do exhibit characteristics of ‘interest’ are destined to suffer greatly by their very nature, and via the experiments to which they will be subjected."
But Mitalipov has defended the research use of what Bailey describes as "highly sentient animals," saying: "We cannot model everything in the mouse. If we want to move stem cell therapies from the lab to clinics and from the mouse to humans, we need to understand what these primate cells can and can't do."
reports the research is published online ahead of the release of the January 20 issue of the journal Cell.