Human + Sheep = Chimera

Professor Zanjani, of the University of Nevada, has announced the breeding of sheep which are 15% human by cell count. In the process Dr. Zanjani injects adult human stem cells (derived from the bone marrow) into the peritoneum of the developing sheep fetus. The cells do not fuse, but the human stem cells divide and eventually specialize into the sheep's organs. Most notably the liver, heart, lungs, and brain.

These organs can be matched to the transplant patient and the idea is to improve the human to sheep ratio to improve the incompatibility of the organ. Animal rights activists have expressed concern over the possibility of the human and sheep cells fusing to create some kind of chimera hybrid, but Dr. Zanjani asserts that this is not possible in this method.