Changes in expressions of red blood cell antigens following gamma irradiation of chicken embryos.

Red blood cells (RBC) from chicken embryos receiving 450 R of gamma-irradiation on the 6th day of incubation displayed various differences from controls with respect to agglutination properties in the presence of antibodies for three blood group antigens as assayed over a period extending from 12 days of incubation to after hatching. An alloantigen (B21), which normally can be detected prior to 10 days of incubation, showed increased agglutinability following radiation exposure at 6 days. Likewise, an 'embryonic' blood cell antigen, which normally would decrease rapidly after 12 days of incubation, persisted in the blood of irradiated embryos. On the other hand, an alloantigen (B19), which normally appears only after 10 days of incubation, was severely depressed in cases where the embryos received 450 R of gamma-irradiation. The authors propose that in the first two instances gene activation (or induction) for the respective RBC antigens had been accomplished prior to radiation exposure, whereas in the last instance induction had not been accomplished prior to the radiation insult and the gamma-rays had strongly interfered with this process.