The Initial Chimeric Monkey has Surfaced, Displaying Dual Sets of DNA

In a scenario reminiscent of the initial scenes in a science fiction horror movie, scientists have injected stem cells from a seven-day-old monkey embryo into an unrelated four-to-five-day embryo of the same species. This combined embryo was then implanted into a female monkey, resulting in the first-ever live birth of a chimeric non-human primate—a fully formed male.

Groundbreaking Results in Chimeric Monkey Development

Scientists have employed this technique to generate both monkey-human embryos (terminated in early development) and live individuals. However, this marks the first instance where the introduced genetic material constitutes a substantial portion of the newborn’s tissue composition. The injected stem cells contributed to 92% of the monkey’s brain tissue and comprised 67% of the animal’s overall makeup.

“This accomplishment is a longstanding aspiration in the field,” remarked Zhen Liu, a senior author from the Chinese Academy of Sciences (CAS). “This achievement has the potential to enhance the creation of more precise monkey models for the study of neurological diseases and other biomedical research.“

The researchers, however, were not only surprised by the successful birth but also by the unprecedentedly high contribution of embryonic stem cells to fetal development. To track the extent of this genetic material’s involvement in the monkey’s formation, pluripotent cells, capable of differentiating into all necessary cell types, were labeled with green fluorescent protein.

Observations and Analysis of Fluorescent Patterns in Chimeric Monkey Offspring

Following the birth, researchers noted distinct fluorescent patches on the body of the newborn cynomolgus macaque (Macaca fascicularis), including its fingertips and eyes. Through gene sequencing and various tests, it was revealed that donor stem cells were present in 26 different types of tissue, constituting between 21% and 92% of each tissue.

In total, the injected stem cells contributed to an average of 67% of the monkey’s tissue, distributed across the brain, heart, kidneys, liver, gastrointestinal tract, testes, and other organs.

“We observe a significant level of contribution, with donor cells playing a substantial role in forming various tissues and complex structures throughout the monkey’s body,” stated Professor Mu-Ming Poo, the scientific director of the Institute of Neuroscience at CAS.

Regrettably, the young monkey’s life spanned only 10 days before succumbing to respiratory failure and hypothermia, necessitating euthanasia. The exact cause of this deterioration remains unknown, but Liu suggests it may be attributed to epigenetic differences among the cell types.

Ethical Considerations and Future Implications of Chimeric Organism Creation

The creation of sentient animals through genetic manipulation has sparked ethical concerns and remains a contentious area of scientific exploration. Termed a chimera, this organism results from cells with different genetic origins. In contrast, a clone is a genetically identical copy of another organism. While the ethical implications are profound, there is interest in developing viable chimeric organisms for growing human organs and gaining insights into human diseases. The researchers also propose the potential use of interspecies chimeric animals to aid in the conservation of critically endangered species.

Liu Zhen, the senior author of the paper from the Chinese Academy of Sciences (CAS), emphasizes the potential of this work in generating more precise monkey models for studying neurological diseases and other biomedical research.

Historically, researchers have predominantly focused on creating chimeric rodents. However, due to the close evolutionary relationship between primates and humans, monkeys are considered a crucial resource for gaining deeper insights into human physiology and diseases.

“Mice fail to replicate numerous aspects of human disease due to their distinct physiology,” explained Zhen Liu, the senior author of the study. “In contrast, the close evolutionary relationship between humans and monkeys allows for a more accurate modeling of human diseases in monkeys.”

Read the original article: New Atlas

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