Table 3.

Synonymous codon usage in PRRSV ORFs.

AAa	Codon	RSCUb	AAa	Codon	RSCUb
Ala	GCA	0.857	Leu	CUA	0.510
	GCC	1.309		CUC	1.164
	GCG	0.650		CUG	1.377
	GCU	1.184		CUU	1.096
Arg	AGA	0.893		UUA	0.330
	AGG	1.092		UUG	1.522
	CGA	0.742	Lys	AAA	0.997
	CGC	1.411		AAG	1.003
	CGG	1.012	Phec	UUC	0.917
	CGU	0.851		UUU	1.083
Asn	AAC	1.040	Proc	CCA	1.047
	AAU	0.960		CCC	1.059
Aspc	GAC	0.955		CCG	0.802
	GAU	1.045		CCU	1.092
Cys	UGC	1.001	Ser	AGC	0.872
	UGU	0.999		AGU	0.806
Gln	CAA	0.982		UCA	1.075
	CAG	1.018		UCC	1.418
Glu	GAA	0.884		UCG	0.683
	GAG	1.116		UCU	1.145
Gly	GGA	0.559	Thr	ACA	0.969
	GGC	1.369		ACC	1.439
	GGG	1.016		ACG	0.653
	GGU	1.056		ACU	0.939
Hisc	CAC	0.847	Tyr	UAC	1.174
	CAU	1.153		UAU	0.826
Ile	AUA	0.766	Val	GUA	0.365
	AUC	1.166		GUC	1.110
	AUU	1.068		GUG	1.406
				GUU	1.118

The preferentially used codons for each amino acid are described in bold.

^aAA is the abbreviation of amino acid.

^bRSCU values are mean values.

^cThe preferentially used codon is U-end codon.