When copying the HTT gene, DNA polymerase can basically lose track of which CAG it's on and accidently add extra CAGs.

当HTT基因复制时，DNA聚合酶基本上无法别校对CAG列，意外地导致CAG列重复。

And they combed through those samples using software that recognized viral DNA sequences.

他们通过软件别病毒DNA列来筛样本。

The method allowed scientists to isolate and identify variable elements within a DNA sequence.

该方法允许科学家分离并别DNA列中的可变元素。

They were thought to do so aimlessly, but in 2017 it was discovered that some contained gene editing systems that were very good at recognizing specific DNA sequences.

人们认为它们样做是毫无目的的，但2017年发现其中一含有非常擅长别特定DNA列的基因编辑系统。