Table 1. Nucleotide and amino acid changes in wild-type and mouse-adapted influenza virus B/Florida/04/2006.

Genesegment	Changed nucleotidesa			Changed amino acidsb
	Position	Original	Mouse- adapted	Position	Original	Mouse-adapted
HA	951	T	A	317	P	—
	1271	A	G	424	D	G
M1c	719	A	C	240	N	T
BM2c	27	C	T	9	I	—
NP	40	A	G	14	N	S
	882	G	C	294	K	N
PA	1825	G	A	609	V	I

^aNumbering of nucleotides is relative to B/Lee/40 and begins at the start of the non-coding region of the RNA segment.

^bNumbering of amino acids is relative to B/Lee/40 and begins at the start of the coding region.

^cRNA segment 7 encodes two polypeptides, M1 and BM2, using tandem cistrons.