Jawless Fish Have Form of Adaptive Immunity

摘要

Evolution doesn't like to do things just once. It came up with flight three times, for example—in insects, birds, and bats. Now it appears that evolutionarily distinct immune systems have exploited a similar genetic trick to battle microbes. New research on page 1970 reveals that the immune defenses of jawless fish such as lampreys generate as much diversity as the immune system that organisms from sharks onward in evolution use. And both employ a similar technique: rearranging DNA.