Digging a narrow tunnel through the earth would make any mammal struggle for air. But the Eastern mole (Scalopus aquaticus) has found a unique way to cope. Other moles have evolved hemoglobin proteins that grab oxygen very efficiently, though the proteins have only a limited number of sites to bind the gas. Eastern moles have taken a different approach: According to a genetic scan reported  online in BMC Evolutionary Biology, the hemoglobin of Eastern moles does not bind with oxygen well, but it contains many more sites to grab the gas. In the end, this helps Eastern moles breathe just as easy as do other mole species. The discovery of this mechanism, say researchers, could provide a way to create new varieties of hemoglobin for use in artificial blood substitutes.
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