In Greek mythology, the chimera was a monster with the head of a lion, the body of a goat, and a serpent for a tail. However, in real life, chimeras are any organism that possess two different sets of DNA. For instance, a twin that absorbs their sibling in utero or the recipient of a bone marrow transplant often become chimeras naturally because of the changes to their body’s cells.

Human animal chimeras have been a big part of scientific research for decades, with lab mice often genetically engineered with human cells to replicate our immune systems to better test drug efficacy. These chimeras are created by injecting human stem cells into animal embryos to create whatever tissue is needed for research.


Human animal chimera research has hit new strides since the U.K. government lifted a ban on research funding in 2016. By 2017, British scientists were able to create the first viable pig-human chimera embryo, a first step towards research that seeks to grow human organs within animal chimeras for the purposes of organ transplantation.

In 2018, another research project used human-chicken chimera embryos to discover “the organizer” embryonic cell region in primates. The organizer is a key cell region in embryo development that determines the growth of the central nervous system.

In fact, the organizer had first been discovered in chimera research on amphibians all the way back in 1924 by Hilde Mangold and Hans Spemann, though it’s taken almost a century to find the same cell region in primate mammals.


While there’s a high amount of potential for genetic chimera research, it still holds considerable ethical ramifications and associated restrictions.

For instance, there are strict policies around chimera projects where human cells might make into the chimera’s brain or nervous system, affecting their perception in unexpected ways. Additionally, some districts restrict the creation of human-primate chimeras due to their genetic proximity to humans.

Of course, if we ever do get to the point where human organs can be grown inside animal chimeras, that could lead to a whole other conversation about animal cruelty.

Nonetheless, the research ramifications of human-animal chimera research are invaluable. Through chimera research, our understanding of embryonic development and the differentiation of stem cells has evolved by leaps and bounds and that will only escalate as more advanced methods are developed.

At RegenerVate, we understand how stem cells can be used to repair and regenerate damaged joint and muscle tissue. Our non-invasive stem cell therapies harness the power of your body’s own stem cells in order to heal your chronic pain. Contact us today for a consultation.