Recently scientists have created part human, part big embryos. They contain a ‘low’ amount of human tissue. The human-animal hybrid or ‘chimera’ was created when the human stem cells were injected into pig embryos and implanted in a sow.
Afterwards these human cells grew and as a result formed part of the tissue of the pig embryos. But they didn’t become piglets because they were removed through 28 days. According to researchers the amount of human tissue was ‘low’. The whole organs needed to be grown for use in transplantation. Anyway, it is considered to be a great step when they will grow human organs in many other animals. The problem is there is a great shortage of organs for transplant, so this technique will allow the organs in the pig to be grown of human cells.
According to the NHS three people each day die in the UK and 12 people in the US. This is because replacement organs cannot be found. The research raises some ethical issues. If too much human DNA is introduced in a pig’s embryo, then a pig may also have a human brain and human face but these concerns haven’t been yet realized.
The director of Human Genetics Alert, Dr David King said that these experiments may seem confusing. According to him in mythology human-animal creatures were considered as monsters. He is afraid that the human organs and tissues which are produced in pigs may contain pig viruses which will affect the human population. Mixing species may have bad results and it can be about the unwisdom of scientists. The creation of human-pig ‘chimera’ was the first scientific report published in the journal Cell.
Another attempt to create a cow-human embryo was rejected as it was costly and very difficult. As it is said, pigs are five times more distant from evolution than mice and rats. Pig embryos develop faster than human embryos, but the professor at Stalk, called Juan Carlos Izpisua Belmonte, says that it is a great step to grow some transplantable tissues or organs. He says that human cells should be injected into the pig embryo which is grown in the laboratory at that exact time, otherwise there will be accidents because of the different speeds.
It has always been considered impossible to grow large three-dimensional organs out of living creatures. Besides providing a source of transplant organs, chimeras can be used in testing drugs. According to the researchers, the most potential human stem cells are pluripotent stem cells which survive longest into big embryos. These cells formed a human-pig chimera embryo by surviving longer. The scientists say that it is great news to know that the pig embroys didn’t develop human brains. Due to 28 days they understood the whole process very well. They also confirm that their next step is to improve efficiency in the human cells and form a particular organ in pigs. Anyway, much more research is needed for the further developments!