> I suppose if people were inserting furin cleavage sites specifically into the Sars-CoV-2 precursor sequence, then they might generate a series of variants to see which one worked best when it came to results of infectivity tests in human cell lines?
This makes sense.
I think here's the most relevant quote from that article: "So far, no betaCoVs from the sub-genus Merbecovirus have been detected in bats of suborder Yinpterochiroptera."
While the paper does mention one member of Yangochiroptera (Chaerephon plicatus) that has been discovered infected with sarbecoviruses, it looks like there's little room for infectious overlap of merbecoviruses and sarbecoviruses (which predominantly infect Yinpterochiropterans, at least as detected as of the paper publication).
So if the SARS-CoV-2 progenitor did get its furin cleavage site from a co-infection with a merbecovirus, this would have been a really rare event indeed. At least if the co-infection happened in a bat species, and not in another animal or a human who deals with bats.
This makes sense.
I think here's the most relevant quote from that article: "So far, no betaCoVs from the sub-genus Merbecovirus have been detected in bats of suborder Yinpterochiroptera."
While the paper does mention one member of Yangochiroptera (Chaerephon plicatus) that has been discovered infected with sarbecoviruses, it looks like there's little room for infectious overlap of merbecoviruses and sarbecoviruses (which predominantly infect Yinpterochiropterans, at least as detected as of the paper publication).
So if the SARS-CoV-2 progenitor did get its furin cleavage site from a co-infection with a merbecovirus, this would have been a really rare event indeed. At least if the co-infection happened in a bat species, and not in another animal or a human who deals with bats.