Chinese researchers introduce clone monkey who is over three years

Researchers in their new study published earlier this week introduced a cloned monkey which came into being on July 2020, and currently in good health and growing strong.

The monkey is over three years old and is named Retro, Falong Lu, one of the study’s authors said.

This monkey has become the second species of primate that has been cloned after the two cynomolgus monkeys who still live today.

“We have achieved the first live and healthy cloned rhesus monkey, which is a big step forward that has turned impossible to possible, although the efficiency is very low compared to normal fertilized embryos,” said Lu, who is also an investigator at the State Key Laboratory of Molecular Developmental Biology and Institute of Genetics and Developmental Biology at the Chinese Academy of Sciences.

He added: “Currently, we haven’t had the second live birth yet.”

Scientists cloned the first mammal — a sheep named Dolly — in 1996. They also endeavoured to develop other mammal species as well however, they were unsuccessful.

Miguel Esteban, principal investigator with the Guangzhou Institute of Biomedicine and Health at the Chinese Academy of Sciences, said: "In a way we have made much progress in that, after Dolly, many mammalian species were cloned, but the truth is that inefficiency remains a major roadblock."

The Shanghai-based team of scientists used a modified techniques in their work on cynomolgus monkeys (Macaca fascicularis) and changed the method further to clone the rhesus monkey (Macaca mulatta).

After several failures, scientists identified a problem associated with the development of the outer membrane.

To cope with this problem, Esteban explained that scientists carried out a process called inner cell mass transplantation, involving cloned inner cells into a non-cloned embryo, and allowed the clone to develop normally.

According to the research published in the journal Nature Communications, the method was tested to develop embryos that resulted in only one live birth.

According to Lu, “there might be additional…. abnormalities to be fixed.”

“Strategies to further enhance the success rate of SCNT in primates remains …our main focus in the future.”

The researchers said that being able to successfully clone monkeys might help accelerate biomedical research given that there are limitations on what scientists can learn from lab mice.

Study on nonhuman primates, — closer to humans — has been central in lifesaving medical achievements such as development of vaccines.

Esteban said: “This research is proof of principle that cloning can be done in different non-human primate species and opens the door to new ways of enhancing the efficiency. Cloned monkeys can be genetically engineered in complex ways that wild-type monkeys cannot; this has many implications for disease modeling. There is also a species conservation perspective.”