Monkey cloning by Chinese scientists causes controversy – 01/17/2024 – Science

Chinese scientists have cloned the first Rhesus monkey, a species widely used in medical research due to its physiology similar to that of humans.

Cloned laboratory monkeys have the potential to speed up drug testing, as genetically identical animals produce similar results, providing greater precision in trials.

Previous attempts to clone a Rhesus were unsuccessful, with the creatures dying shortly after birth. An animal rights organization has expressed “deep concern” about this cloning.

Sexual reproduction in mammals results in offspring with a combination of genes from the father and mother.

In cloning, techniques are used to create a genetically identical copy of a single animal.

Dolly the sheep, the most famous cloned animal, was born in 1996, and scientists reprogrammed skin cells from another sheep to create embryos, made up of basic cells capable of developing in any part of an organism. These embryos were then implanted into Dolly’s surrogate mother.

In an article in the journal Nature Communications, researchers claim to have carried out essentially the same process, but with a Rhesus monkey.

They report that the animal remained healthy for more than two years, indicating the success of the cloning process.

Scientist Falong Lu, from the University of the Chinese Academy of Sciences, told the BBC that “everyone was beaming with happiness” with the result.

However, a spokesperson for the Royal Society for the Prevention of Cruelty to Animals (RSPCA) in the United Kingdom claimed that the organization believes that the suffering caused to animals outweighs any immediate benefit to human patients.

Rhesus monkeys are found in the wild in Asia, with populations in Afghanistan, India, Thailand, Vietnam and China.

They are used in experiments to study infections and immunity. The first monkeys were cloned in 2018, but medical researchers prefer Rhesus monkeys due to their genetic similarity to humans.

Complications

The challenge of reprogramming adult cells to make them embryonic lies in the fact that in most attempts, errors occur in reprogramming, resulting in very few embryos that are actually born, and even fewer that are born healthy, generally between 1% and 3% in most mammals.

This process proved even more complex with Rhesus monkeys, with no successful births until two years ago.

They found that in the unsuccessful Rhesus attempts, the placentas, responsible for providing oxygen and nutrients to the growing fetus, had not been properly reprogrammed during the cloning process and, as a result, did not develop normally.

The researchers solved the problem by not using the part of the cloned embryo that later develops to become the placenta, that is, the external part.

Instead, they extracted the internal cells, which develop in the animal’s body, and inserted them into an external, uncloned embryo, hoping it would grow into a normal placenta.

Retro

The researchers used 113 embryos, of which 11 were implanted, resulting in two cases of pregnancy and one birth. The monkey was named “ReTro”, in honor of the scientific method called “trophoblast replacement”, in English, used to create the animal.

The Royal Society for the Prevention of Cruelty to Animals claimed to have serious doubts about the research.

“There is no immediate application for this study. We are expected to assume that human patients will benefit from these experiments, but any real-life application will take years and it is likely that more animal ‘models’ will be needed to develop these technologies,” he said. a spokesperson.

“The RSPCA is deeply concerned about the large number of animals that suffer and are distressed in these experiments, and the very low success rate. Primates are intelligent and sensitive animals, not just research tools,” he concluded.

Concerns

Professor Robin Lovell-Badge of the Francis Crick Institute in London also expressed his concern, strongly supporting animal research only when the benefits to patients outweigh the suffering of the specimens.

He pointed out that “having animals with the same genetic makeup will reduce a source of variation in experiments, but one has to question whether it is really worth it.”

“The number of attempts required was enormous. They had to use many embryos and implant them in many surrogate mothers to get an animal born alive”, argued the professor.

He also expressed concern that scientists had only achieved one live birth.

“You cannot draw conclusions about the success rate of this technique when there is only one birth. It is absurd to say that it is possible. You need at least two, preferably more,” said the professor.

In response, Falong Lu told BBC News that the team’s goal is to get more cloned monkeys while reducing the number of embryos used.

He assured that he had obtained all ethical approvals for the research.

“All animal procedures in our research followed the guidelines established by the Animal Care and Use Committees of the Shanghai Institute of Biological Sciences, the Chinese Academy of Sciences (CAS), and the Institute of Neuroscience of the Center of Excellence in Brain Science and CAS Intelligence Technology.”

He stated that the protocol was also approved by the Animal Care and Use Committee of this important Chinese research center based in Shanghai.