The " retro" part of retrovirus isn't referring to its style, but refers to it needing to use an enzyme called reverse transcriptase to transcribe a complementary double-stranded piece of " proviral" DNA.
Scientists wanted to know the structure of a protein-cutting enzyme produced by a retrovirus similar to HIV. They haven't been able to solve the protein structure using standard computational methods.
RNA tests screen for viral RNA, so they also detect the virus directly, and DNA tests look for copies of the viral RNA (since remember it's a retrovirus so it copies its genetic material into DNA).
So researchers think that, more than 190 million years ago, some retrovirus attacked one of our mammal ancestors, and inserted bits of its genetic material into its host's DNA that made that viral protein.
因此,研究员认为, 在 1.9 亿多年前,一些逆转录病攻击了我们的哺乳动祖先之一,并将其遗传质的一部分插入宿主的 DNA 中, 从而产生该病蛋白。