by: Carol Szczepaniak
An international research team from China and the US has made history by successfully injecting human stem cells into macaque monkey embryos, and growing them in the lab for 20 days. This kind of creation is referred to as a chimera, named after a Greek mythological monster, because it is the blending of DNA from distinctly different species. The hypothetical goal is to gain understanding of and new treatments for human diseases, as well as find an animal wherein human organs can be grown for transplantation.
The same research team has worked unsuccessfully for a decade to grow human organs in pigs. However, monkeys may lead to success due to our genetic similarities. While the need for healthy transplantable organs (such as kidneys or lungs) is high, this pursuit of human-animal chimeras is rife with ethical red lines. Firstly, the human stem cells used are from in vitro fertilization embryos or aborted human fetuses, which constitute the destruction of a human life. Secondly, the human DNA is incorporated into all the cells of the nonhuman species (such as the brain, sperm or eggs), not just the targeted “human” organ. Thirdly, these “part-human” chimeras will have to be brought to full term and be born in order to harvest the needed organs for transplantation.
The result will be a creature not fully human, nor fully monkey. Could these chimeras have human features or will their cognitive function be more human than monkey? What moral status will these inter-species creations be granted, and by whom? Will there be a need to study them for a time after birth to determine if they have self-awareness of suffering and moral consciousness? Finally, could this chimera research lead us past organ development and turn the tables by inserting animal DNA which imparts strengths/capabilities into human embryos brought to term? Once again scientific research plows far ahead while hoping that ethical considerations and moral consensus will catch up.
NCER asks the following:
- Are there other ethically sound ways to increase organ donations to those in need?
- Can ethical Adult Stem Cells be used exclusively in this research?
- Can human stem cells be blocked from becoming brain/sperm/egg cells in the chimera?
Links for more details