TOLERANCE BETWEEN HOST AND DONOR TISSUE IN BIRDS

Two methods were used to develop tolerance in the host toward donor cells. In the first method chicken embryos were joined by the parabiotic union of the chorioallantoic membranes after 9 days of incubation. The second method consisted of the use of embryonic transplants of limb buds from donor embryo to host embryo. These transplants were made after 96 hours of incubation with chicken embryos. Other species used were incubated to comparable development. Both methods were successful in the development of tolerance. However, the degree of tolerance attained varied within each method.