Table 1.

Differences between the wild-type IBV strain YN and the embryo-attenuated YN strain aYN.

Locationa	Nucleotide differenceb	Amino acid differencec	Gene region	Location	Nucleotide difference	Amino aciddifference	Gene region
808	A→C	K→T	1a	20659	A→G	K→R	S
2764	C→T	P→L	1a	20722	T→C	F→S	S
2892	G→A	E→K	1a	21370	G→A	R→K	S
3996	C→T	L→F	1a	21543	C→G	R→G	S
5815	A→G	N→S	1a	22434	C→T	P→S	S
6466	C→T	P→L	1a	22842	T→G	Y→D	S
7359	T→C	W→R	1a	23835	G→T	E→*	S
9553	A→G	D→G	1a	25068	A→G	T→A	M
14547	C→T	A→V	1b	25140	G→A	E→K	M
19659	C→T	S→L	1b	25527-25607	81 nt deleted	ORF missing	5a
20455	T→C	V→A	S	26519	G→T	R→L	N
20515	C→T	T→I	S	26908	A→C	T→P	N
20646	A→G	M→V	S	26987	C→T	P→L	N

^aAccording to the IBV wild-type YN strain derived sequence. The entire sequence has been submitted to the GenBank database.

^bLeft nucleotide according to the wild-type YN strain sequence and the right nucleotide from the attenuated YN strain.

^cLeft amino acid according to the wild-type YN strain sequence and the right amino acid from the attenuated YN strain. *indicates the stop codon.