Nienhuis A W, Bunn H F
Science. 1974 Sep 13;185(4155):946-8. doi: 10.1126/science.185.4155.946.
Sheep and goats switch from the synthesis of hemoglobin A (alpha(2)beta(2)(A)) to hemoglobin C (alpha(2)beta(2)(C)) when made anemic. We have demonstrated the existence of the asymmetrical hybrid hemoglobin, alpha(2)beta(A)beta(C), in the circulating red cells of anemic sheep. These erythroid cells, therefore, synthesized both A and C hemoglobin simultaneously. Thus, the switch appears to be mediated by selective gene expression rather than by a clonal or cellular selective mechanism.
绵羊和山羊在发生贫血时会从合成血红蛋白A（α₂β₂(A)）转变为合成血红蛋白C（α₂β₂(C)）。我们已经证实在贫血绵羊的循环红细胞中存在不对称杂合血红蛋白α₂β(A)β(C)。因此，这些红系细胞同时合成了A和C两种血红蛋白。所以，这种转变似乎是由选择性基因表达介导的，而非由克隆或细胞选择机制介导。
