評(píng)論
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You may have heard that humans and chimpanzees have something like 96 percent of our DNA in common. So why, then, are diseases like cancer so common in humans but so rare in chimps? If our DNA is nearly identical, shouldn't we be at risk for many of the same diseases?
你也許會(huì)聽(tīng)說(shuō)人類和黑猩猩約有96%的DNA相同。那么，為什么人類常常患有比如癌癥這樣的疾病，而在黑猩猩極少呢？如果我們和猩猩的DNA近乎相同，為何在面對(duì)許多相同的疾病時(shí)，我們和猩猩的患病率不同呢？
According to one study, the difference is due to something called DNA methylation, which involves the chemical modification of DNA. Basically, methylation modifies some DNA positions in the genome, and can also signal cells to switch specific genes to the “off” position.
根據(jù)一份研究，造成這種差異的原因是一種被稱為DNA甲基化的物質(zhì)，它與DNA的化學(xué)變化有關(guān)。簡(jiǎn)單來(lái)說(shuō)，甲基化改變了一些DNA在染色體組中的位置，也可以通知細(xì)胞把特殊的基因轉(zhuǎn)換到“關(guān)閉”的位置。
Evidently, humans and chimps have different patterns of DNA methylation. So even though we may share many of the same genes, the ways our cells switch these common genes on and off differs. And because at least some of these genes are linked to diseases including cancer, variations in the way DNA methylation happens among humans and chimps may help explain why chimps seem to avoid diseases common in humans.
顯然，人類和黑猩猩擁有不同的DNA甲基化模式。因此，盡管人類和猩猩有許多相同基因，但是細(xì)胞開(kāi)關(guān)這些相同基因的方式是不同的。而且，因?yàn)檫@些基因中至 少有一部分關(guān)系到包括癌癥在內(nèi)的各種疾病，所以人類和猩猩體內(nèi)DNA甲基化發(fā)生的方式不同，或許就能用來(lái)解釋為什么猩猩能抵御人類常患的疾病。
So what explains the differences among human and chimp DNA methylation? It may be partly biological, but scientists also know that environmental factors can affect methylation. So studying methylation in humans and chimps could give scientists clues about how genetics and environment combine to make humans more vulnerable to cancer and other diseases.
那又如何解釋人類和猩猩DNA甲基化的不同呢？這或許要牽涉到一部分生物學(xué)原理，但是科學(xué)家們也認(rèn)識(shí)到環(huán)境因素能影響甲基化。因此對(duì)人類和猩猩甲基化的研究可能會(huì)給于科學(xué)家們一些線索，以了解到基因和環(huán)境的綜合影響是如何使人類更容易患有癌癥和其他疾病。
