id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-349015-5oisrm5s	Liu, Zhe	Identification of a common deletion in the spike protein of SARS-CoV-2	2020-04-02		.txt	text/plain	1182	63	57	In this study, we identified two variants from the first Guangdong SARS-CoV-2 cell strain, with deletion mutations on polybasic cleavage site (PRRAR) and its flank sites. These data indicate (1) the deletion of QTQTN, at the flank of polybasic cleavage site, is likely benefit the SARS-CoV-2 replication or infection in vitro but under strong purification selection in vivo since it is rarely identified in clinical samples; (2) there could be a very efficient mechanism for deleting this region from viral genome as the variants losing 23585-23599 is commonly detected after two rounds of cell passage. By sequencing the whole genome of SARS-CoV-2, we identified two variants having deletion mutations on polybasic cleavage site (PRRAR) and its flank sites. To investigate whether these deletions described above are random mutations occasionally identified in a strain or would commonly occur after cell passages, we performed whole genome sequencing on the other 21 SARS-CoV-2 viral strains collected after 2 rounds of cell passage in Vero-E6 or Vero cells (Supplemental Table) .	./cache/cord-349015-5oisrm5s.txt	./txt/cord-349015-5oisrm5s.txt