Controversial research generates genetically modified monkey that glows – 11/10/2023 – Science

For the first time, scientists managed to create a chimeric primate in the laboratory, that is, with a large quantity of stem cells from one animal implanted into another embryo.

The cub was euthanized 10 days after birth, due to worsening respiratory conditions and hypothermia.

The research results were published on Thursday (09) in the scientific journal Cell. According to the authors, they could help to better understand the so-called pluripotent stem cells in primates and humans, which could lead, in the future, to more accurate animal models for the study of neurological diseases and for other biomedical studies and, in a more optimistic vision, even in the cultivation of organs for human transplants.

In Greek mythology, Chimera is a hybrid creature. In biology, the term is used to refer to something composed of genetically different cells.

Shiny Monkey

In the study, embryonic stem cells (ESC) were used, which can give rise to any tissue in the body.

The researchers implanted this type of cell from an animal of the species monkey fascicularis in the embryo of another monkey of the same species. At the studied stage, the embryo was not yet very developed and consisted of a maximum of 32 cells.

According to the researchers, some of the puppy’s organs and tissues developed more from its own cells and others, more from implanted cells. Tissue types containing CTE included the brain, heart, kidneys, liver and gastrointestinal tract, as well as the testicles and the cells that eventually become sperm.

The implanted stem cells were labeled with a green fluorescent protein to determine which tissues contained cells derived from them — in addition to other tests to confirm their presence.

For this reason, in the monkey’s photos, the fingertips and eyes, for example, glow slightly green, showing that in these parts of the body there are many cells coming from implanted cells.

According to the researchers, the modified cells accounted for about a third of the monkey. In the case of so-called motor neurons —the nerve cells that control muscles— this number reached 90%.

In previous attempts, although present, donor cells were scarce and did not actually contribute to tissue formation. Therefore, the animal could not be classified as “chimeric”.

First chimeric primate

The baby monkey is not the first chimeric animal to be successfully created in the laboratory. Chimeric mice have been used for research purposes for a long time. The advance in relation to this research is that, for the first time, a primate was created, a group to which human beings belong.

The objective, according to the study authors, is to research diseases resulting from harmful changes in certain genes, identifying at which point in development the genetic defect is most serious, in order to develop therapeutic measures that can reduce these effects or perhaps even prevent them. .

One of the advantages of studying chimeric animals is that the added cells can be genetically modified in a relatively thoughtful way — something that is not possible in embryos without destroying them.

In this way, complex genetic modifications can be introduced into these animals to present symptoms of certain diseases and, subsequently, study ways to treat them.

In a more utopian vision, experts also hope that, in the future, it will be possible to cultivate organs for donation in chimeric animals. For example: creating a pig in a laboratory without a specific organ and, by introducing human stem cells, creating the human organ to be transplanted.

Ethical controversy

The research in China, in addition to the live baby, also gave rise to an aborted chimeric fetus. But for this result, it took more than 200 attempts.

For this reason, the experiment generated controversy in the field of ethics. Due to the similarity between humans and non-human primates, special rules apply to this type of study. For example: these experiments are only approved if there is no other way to achieve the desired result. With a few exceptions, experiments on great apes, i.e. chimpanzees, gorillas and orangutans, are completely prohibited.