美国《大西洋月刊》“转基因食品有非常真实的危险”

    在孟山都公司的官方网站上，有这样的宣告：“测试转基因食品对人类的安全性是完全没有必要、也没有意义的”。这是一个有利于商业的说法，它的依据基础是1960年前后的遗传学理论。这种遗传学理论遵循的是被称为“中心法则”的遗传学原则。中心法则假说是这样的：是DNA（脱氧核糖核酸）在主导细胞；从DNA（脱氧核糖核酸）到细胞之间存在一种单方向运行的指令控制链。

    Monsanto's website states, "There is no need for, or value in testing the safety of GM foods in humans." This viewpoint, while good for business, is built on an understanding of genetics circa 1960. It follows what's called the "Central Dogma" of genetics, which postulates a one-way chain of command between DNA and the cells DNA governs.

“中心法则”——这事很像我们在比萨饼店订购一个比萨饼的过程：在这里，DNA（脱氧核糖核酸Deoxyribonucleic acid的英文缩写）是指所要的比萨饼类型；下的那个订单叫RNA（核糖核酸 Ribonucleic acid英文缩写），订单指示厨师所定制的比萨饼有什么特点。随后烤好交货的比萨饼，就是DNA（脱氧核糖核酸）所编码合成的那个“蛋白质”。

The Central Dogma resembles the process of ordering a pizza. The DNA codes for the kind of pizza it wants, and orders it. The RNA is the order slip, which communicates the specifics of that pizza to the cook. The finished and delivered pizza is analogous to the protein that DNA codes for.

几十年来，科学家们越来越明白，“中心法则”理论只是在大体上正确，它太过简化了。例如不执行编码过程的微小核糖核酸miRNA，并不编码烤制比萨饼的指令、也不干什么事，却能在细胞中移动、并把某些人体的基因表达“沉默”掉。因此，当一段DNA（脱氧核糖核酸）片段在订制一个比萨饼时，它同时有可能攻击带有某个RNA信号的另一家比萨饼店。结果有可能是：别的DNA（脱氧核糖核酸）片段定制的另外的一个比萨饼订单，最终无法完成比萨饼制作完成。

We've known for decades that the Central Dogma, though basically correct, is overly simplistic. For example: MiRNAs that don't code for anything, pizza or otherwise, travel within cells silencing genes that being expressed. So while one piece of DNA is ordering a pizza, it could also be bombarding the pizzeria with RNA signals that can cancel the delivery of other pizzas ordered by other bits of DNA.

科学家们可以利用这个发现去合成一个几乎与miRNA一模一样的小型人工RNA链。通过一种叫作RNA干扰或RNA“敲除”的方法，这些RNA微小片段就能被用来关闭或者“敲除”特定的基因。

Researchers have been using this phenomena to their advantage in the form of small, engineered RNA strands that virtually identical to miRNA. In a technique called RNA interference, or RNA knockdown, these small bits of RNA used to turn off, or "knock down," certain genes.