TABLE 1.

Mutations commonly observed in three virus isolates that cause persistent infections^a

Gene	Nucleotide change	Amino acid position	Amino acid change
NP	A261C	47	Asp → Ala
	G511A/T	130	Met → Ile
	G581T	154	Ala → Ser
F	T5649C	117	Phe → Ser
HN	G7672A	169	Gly → Arg
L	A10607G	425	Ile → Val
	C12627T	1098	Ser → Phe

^aFull-length genomes of three plaque-purified virus isolates were sequenced, and the mutations that were conserved in all three isolates are listed. Mutations in F and HN characterized in this study are italicized.