“Virus” is doing a lot of work here. It makes a big difference whether they’re capable of making phages or mammalian viruses:
Phages:
Often have a small genome, 3 kbp, easy to synthesize
Can be cultured in E. coli or other bacteria, which are easy to grow
More importantly, E. coli will take up a few kb of naked DNA, so you can just insert the genome directly into them to start the process (you can even do it without living E. coli if you use what’s basically E. coli juice)
I could order and culture one of these easily
Mammalian viruses (as I understand the situation)
Much larger genome, 30 kbp, somewhat harder to synthesize
Have to be cultured in mammalian cell cultures, which are less standard
More importantly, mammalian cells don’t just take up DNA, so you’d have to first package your viral DNA into an existing adenovirus scaffold, or some other large-capacity vector (maybe you could do it with a +ve sense RNA virus and a lipid based vector, but that’s a whole other kettle of fish)
The above might be false because I actually have no idea how to culture a de novo mammalian virus because it’s a much rarer thing to do
If they have the equipment to make phages but not to culture mammalian cells then that’s probably fine. If they’re doing AI-powered GoF research then, well, lmao I guess.
DNA phage genomes have a median size of ~50kb, whereas RNA phage genomes are more around the 4kb mark.
Similarily, mammalian DNA viruses are usually >100kb, but their RNA viruses are usually <20kb.
Oddly enough the smallest known virus, porcine circovirus, is ssDNA, mammalian, and only 1.7kb
But yes, mammalian viruses are generally more difficult to culture, probably downstream of mammalian cells being more difficult to culture. Phages also typically only inject their genetic material into the cells, which bootstraps itself into a replication factory. Mammalian viruses, which generally instead sneak their way in and deliver the payload, often deliver their genetic material alongside proteins required to start the replication.
“Virus” is doing a lot of work here. It makes a big difference whether they’re capable of making phages or mammalian viruses:
Phages:
Often have a small genome, 3 kbp, easy to synthesize
Can be cultured in E. coli or other bacteria, which are easy to grow
More importantly, E. coli will take up a few kb of naked DNA, so you can just insert the genome directly into them to start the process (you can even do it without living E. coli if you use what’s basically E. coli juice)
I could order and culture one of these easily
Mammalian viruses (as I understand the situation)
Much larger genome, 30 kbp, somewhat harder to synthesize
Have to be cultured in mammalian cell cultures, which are less standard
More importantly, mammalian cells don’t just take up DNA, so you’d have to first package your viral DNA into an existing adenovirus scaffold, or some other large-capacity vector (maybe you could do it with a +ve sense RNA virus and a lipid based vector, but that’s a whole other kettle of fish)
The above might be false because I actually have no idea how to culture a de novo mammalian virus because it’s a much rarer thing to do
If they have the equipment to make phages but not to culture mammalian cells then that’s probably fine. If they’re doing AI-powered GoF research then, well, lmao I guess.
Minor correction on genome sizes:
DNA phage genomes have a median size of ~50kb, whereas RNA phage genomes are more around the 4kb mark.
Similarily, mammalian DNA viruses are usually >100kb, but their RNA viruses are usually <20kb.
Oddly enough the smallest known virus, porcine circovirus, is ssDNA, mammalian, and only 1.7kb
But yes, mammalian viruses are generally more difficult to culture, probably downstream of mammalian cells being more difficult to culture. Phages also typically only inject their genetic material into the cells, which bootstraps itself into a replication factory. Mammalian viruses, which generally instead sneak their way in and deliver the payload, often deliver their genetic material alongside proteins required to start the replication.
I was corrected on this, according to them, they’re not working on phages specifically.