The Accidental Immune System Long ago, a wandering piece of DNA- perhaps from a microbe- created a key strategy

摘要

Immunologists have wrestled with the origin of GOD for several decades. This spiritual-sounding acronym stands for "generation of diversity" and emerged in the jargon of scientists after their realization in the 1970s that the human immune system manufactures tens of millions of distinct antibodies. These elaborate, Y-shaped molecules latch onto and help destroy infectious microorganisms. Since the human genome seems to contain fewer than 100,000 genes, the remarkable variety of antibodies initially baffled researchers. How could so few genes produce so many antibodies?