MOSAIC HEMOGLOBIN TYPES IN A PAIR OF CATTLE TWINS.

Erythrocyte mosaicism for hemoglobin types is demonstrated in a pair of dizygotic cattle twins. Both twins were of hemoglobin type AB in the direct tests. However, when hemoglobin types were ascertained on the two populations of red cells comprising the mosaic, one population proved to be hemoglobin type A and the other, type B. Since the ratio of the two populations of red cells was approximately 60:40, there was no evidence from the direct tests suggesting mosaicism for hemoglobin types. The results, as might be expected on theoretical grounds, provide evidence that synthesis of hemoglobin of one type in a mixed clone is not influenced by synthesis of hemoglobin of another type.