Thread: Retrovirus RNA Insertion, Random?

Title asks it all. Is the RNA of a virus inserted into the host's genome randomly? For instance does it insert itself randomly anywhere within the 3 billion nucleotides of a human's genome?

Thanks.

A little note first: The RNA of a retrovirus is not inserted into the host genome. It must first be reverse-transcribed to DNA, which is then inserted into the genome.

Where it is inserted is pretty much random. Since biology doesn't like neat little rules without exceptions, there are some points to be aware of: some retroviruses prefer to insert within genes, some choose locations near promoters, and some settle down in genomic wasteland, while others just pick anywhere at all. The specific insertion site itself, at the sequence level, seems to be random. A particular retrovirus does not seek out a specific target sequence for integration.

I'll echo Zwriko's answer and also add that some viruses have specific preferred integration sites. Although not a retrovirus, AAV inserts its genome most often at one site in chromosome 19, and generally nowhere else. It inserts at a low frequency though, meaning it's unlikely to do it at all.

They have a "target" sequence that is used as an insertion site, although those sequences are usually very short so in practice can be considered random.

Cheers