¿La hemoglobina, es un marcador genético invariable? Hallazgos en la gallina criolla andina.

Resumen

Chicken (Gallaus gallus) were introduced in South America during the Spanish conquest and therefore their adaptation time to high altitude is approximately 500 years. A group of chicken from the Peruvian Andes (4,000m) carrying a high hemoglobin-oxygenaffinty has been identified and reproduced at sea level. The hemoglobin-oxygenaffinity (P ₅₀) has been determined, by a mixing technique, in whole blood and in phosphate-free hemoglobin solutions before and after the addition of inositol hexaphosphate (IHP). The Andean chicken alpha and beta globin genes were sequenced. A mutation Thr → Ser in position 69 of the β chains of Hb A has been found. The addition of IHP to the significantly less in the sea-level chicken (42.2 torr) suggesting that the high-affinity hemoglobin is probably dependent on a moleculara change affecting the allosteric regulation. These findingshow the unprecedent observation in nature of a hemoglobin genetic change in  an exceptionally short evolutionary time in a sea-level terresrial bird. This observation also shows that the same species can be differentiated from its sea-level counterpart by a genetic change in the Hb function as a reflect of its structure.