Table 2.

Identification of non-essential regions of PRRSV genome.

Genotype and gene		Mutation/deletion (nts or aa)	Motif	Infectious clone	Growthd	GenBank
II	5′UTR	1–3 nts	N/A	pAPRRS	N/A	GQ330474.2
II	nsp2	13–35 aa	hypervariable	pVR-V7	↓	DQ217415
II	nsp2	324–726 aa	hypervariable	pVR-V7	↓	DQ217415
II	nsp2	727–813 aa	hypervariable	pVR-V7	↓	DQ217415
II	nsp2	480–667 aa	hypervariable	pHuN4-F112	N/A	EF635006
I	nsp2	691–722 aa	ES3a	pSD01-08	↑	DQ489311
I	nsp2	736–790 aa	ES4a	pSD01-08	nc	DQ489311
I	nsp2	1015–1040 aa	ES7a	pSD01-08	↓	DQ489311
II	ORF7	5–13 aa	N/A	pAPRRS	↓	GQ330474.2
II	ORF7	39–42 aa	N/A	pAPRRS	↓	GQ330474.2
II	ORF7	48–52 aa	N/A	pAPRRS	nc	GQ330474.2
II	ORF7	120–123 aa	N/A	pAPRRS	nc	GQ330474.2
II	ORF7	43,44 aa	NLSb	pCMV-S-P129	↓	AF494042
II	ORF7	43,44,46 aa	NLSb	pCMV-S-P129	↓	AF494042
II	ORF7	46,47 aa	NLSb	pCMV-S-P129	↓	AF494042
I	ORF7	123–128 aa	N/A	pABV437	nc	N/A
I	3′UTR	14989–14995 nts	N/A	pABV437	nc	N/A
II	3′UTR	15370–15409 nts	N/A	pAPRRS	N/A	GQ330474.2

N/A, not application. “nc” stands for no change.

^aThe abbreviation, ES, stands for the immunodominant B-cell epitopes identified in type I PRRSV.ES2-ES7 are identified in nsp2 encoding regions (Oleksiewicz et al., 2001).

^bNLS stands for the nuclear localization signal which mediates the nuclear localization of PRRSV N protein.

^c Ref. Seq. is the abbreviation of reference sequence, and GenBank accession numbers for each construct are provided.

^dSymbols “↑” and “↓” indicate increased or reduced virus growth respectively.