Thursday, January 26, 2017
Human-pig embryos created in a step towards using animals for human organ transplants
PHOTO: Pigs at the Agropor facility in Spain being used in the chimera experiments. (Supplied: Juan Carlos Izpisua Belmonte / Cell Press)
It may be possible one day to grow human organs inside other animals for use in transplants, as scientists successfully create the first human-pig hybrid embryo.
The embryo contains genetic information from both species, pig and human.
The results were published in the journal Cell, but scientists warn any such technological and scientific applications are still far away.
Dr Jun Wu, from the Salk Institute in the US and the lead author of the research, said it was the first time they had successfully generated a human-pig chimeric embryo.
"What that means is that we used the human stem cells, and saw the human cells can survive and differentiate into early stages of tissues inside a live pig embryo," he said.
"Prior to our study, we were really not sure whether the human cell had the ability entering in to the pig development, because pig and human are very distant species — they diverged about 95 million years ago."
Previous studies had shown getting the genetic material of one animal to grow in another was possible.
PHOTO: Cells derived from rat pluripotent stem cells (PSCs) were enriched in the developing heart of a genetically modified mouse embryo. (Supplied: Salk Institute)
In 2010, researchers grew a rat/mouse chimera, but both those animals are far more genetically similar than humans and pigs.
The researchers said it was a major finding to show that the cells of two large mammals, humans and pigs, were compatible.
"The first important question before we dream about human organs, we need to have the human cells that can contribute and differentiate inside the pig embryos," Dr Wu said.
"So that is one of the main findings from this study."
Despite years of attempts, scientists have struggled to get human stems cells to develop into specialised cells in petri dishes.
Juan Carlos Izpisua Belmonte, from the Salk Institute and another author of the study, said it was difficult to provide stem cells the right environment.
"It is very difficult in a petri dish to provide human cells with all the signals that gives life to an organ that has taken millions of years of evolution during the development of an animal to take place," Professor Izpisua Belmonte said.