- This note page will explain how animals can be genetically engineered for xenotransplantation.
- This note page will also discuss the ethical issues brought up by genetic manipulation in plants, animals, humans and microorganisms.
Xenotransplantation- the transplantation of cell tissues or organs between animals of different species. For example, using pig organs to transplant to humans when there is a shortage of donor organs.
Allotransplantation- the transplantation of cell tissues or organs between animals of the same species, For example, a kidney transplant between two humans.
Unfortunately, there is currently a worldwide shortage of donor organs- a massive figure of 60% of people awaiting replacement organs die whilst on the waiting list, so scientists have been advancing transplantation technology in order to establish whether xenotransplantation is possible.
Pigs have been considered for xenotransplantation because their organs are roughly around the same size as a humans. The main problem with xenotransplantation is the issue of organ rejection- immunosuppressant drugs are used in allotransplanted human organs, because even human to human transplants have rejection issues, unless the organ has come from a genetically identical source.
Scientists in 2003 managed to engineer pigs to lack the enzyme alpha-1,2-transferase (this is an enzyme that causes graft rejection in humans), which was a significant step closer to xenotransplantation becoming possible. In 2006, scientists in the UK and in Poland engineered a human nucleotidase enzyme called E5'N into pig cells in culture, which reduced the activity of immune cell activities that caused organ rejection. Future developments could well open up the possibility of animal organs and tissues being used instead of human organs.