They're also single-stranded, positive-sense ribonucleic acid, or RNA, viruses.

它们也是单链、正义核糖核酸（RNA）病毒。

And RNA viruses can mutate much faster.

RNA 病毒的变异速度要快得多。

Coronaviruses store their genes on RNA. All viruses are either RNA viruses or DNA viruses.

冠状病毒将其基因存储在 RNA 上。所有病毒要么是RNA病毒，要么是DNA病毒。

This makes coronaviruses much more stable, with a slower mutation rate, than other RNA viruses.

这使得冠状病毒比其他 RNA 病毒更稳定，突变率更慢。

Coronaviruses have a few key differences from most RNA viruses.

冠状病毒与大多数RNA病毒有一些关键区别。

In general, RNA viruses don't have a proofreading mechanism, whereas DNA viruses do.

一般来说，RNA病毒没有校对机制，而D​​NA病毒有。

RNA viruses tend to be smaller, with fewer genes, meaning they infect many hosts and replicate quickly in those hosts.

RNA 病毒往往更小，基因更少，这意味着它们会感染许多宿主并在这些宿主中快速复制。

With RNA viruses, many of them stay in the cytoplasm where the viral RNA is used by the host's ribosomes to create viral RNA polymerase proteins.

对于RNA病毒，它们中的许多都待在细胞质中，病毒RNA在这里由宿主的核糖体合成病毒RNA聚合酶。

Now this virus is a single-stranded RNA virus, and it's also a negative sense, meaning it first has to be transcribed by RNA polymerase into a positive-sense mRNA strand.

麻疹病毒是一种单链RNA病毒，也就是负义链的病毒，这意味着它首先必须被RNA聚合酶转录成正义mRNA链（正义链与反义链互补）。