Pig embryos could provide sources of new organ and tissue transplants for people, and they may pose fewer risks than using material from adult animals, Israeli researchers reported on Monday.They found that if cells were taken from pig embryos at precisely the right time, they grew into liver, pancreas and lung tissues in mice."Considering the ethical issues associated with human embryonic stem cells or with precursor tissue obtained from human abortions, we believe that the use of embryonic pig tissue could afford a more simple solution to the shortage of organ donors,” said Yair Reisner of the Weizmann Institute of Science, who led the study.Writing in the Proceedings of the National Academy of Sciences, Reisner and colleagues said their findings also help explain why earlier experiments did not work. If transplanted at the wrong time, they found the pig embryo cells grew into tumors called teratomas instead of the desired tissue.
