American scientists have discovered that the Tibetan antelopes have adapted to life under hypoxic conditions in an unexpected way. Other Alpine animals achieve the effective transport of oxygen by using various kinds of mutations in glavinovich genes (which encode the protein part of hemoglobin). Antelope lost the “adult” form globin entirely, leaving himself only “kids” options that better contact with oxygen. Work published in the journal Science Advances.
In vertebrates, the genes encoded several forms of hemoglobin, and during the life of the organism can switch from one to another. An example of this occurs in mammals after birth. The fact that in the womb the child needs an isoform, which binds stronger than oxygen — it allows you to compete with the mother’s red blood cells and enhances the transport of gases through the placenta. After birth it is not necessary, and in the adult, red blood cells contain a different isoform.
Sometimes in an adult organism are produced by both isoforms, and it can facilitate human life, if it is “adult” hemoglobin bred mutation, such as in thalassemia — in this case “child” protein compensates for the defects of the adult. It also happens that in the body of the mammal forms of hemoglobin are switched depending on the situation — for example, during hypoxia of sheep and goats start to produce more “children’s” version of the protein.
Anthony Signoret (Anthony Signore) and Jay Storz (Storz Jay) from the University of Nebraska suggested that similar mechanisms may prove useful and highland animals who often find themselves in conditions of oxygen deficiency. Their object of study they chose the Tibetan antelope (Panthelops hodgsonii), which lives at the altitude of 3600-5500 m above sea level, where oxygen partial pressure is two times lower than on the coast — that does not prevent animals jumping over the mountains at speeds of more than 70 kilometers per hour.
For a start, researchers described the locus of β-glavinovich genes (depends on type of the protein part of hemoglobin) from the Tibetan antelope. It is known that the closest relatives of the antelope — cows, goats and sheep — this locus is arranged differently. In cows it has two variant globin: βA, which forms the “adult” form of the protein, and βF, which is responsible for the “children” option. Goats and sheep the same, and βA and βF work in adulthood, but there is a third option, βС, which is expressed in embryos.