Table 3. Nucleotide sequence diversity of PPV3 within 4 farms.

Farm	“sequence group”						Nucleotide difference
	1a)	2	3	4	5	6
A		JP I5				JP I7	Sequence groups 2 vs 6: 1.3% (8/622)
						JP I8
						JP I9
						JP I10
B	JP I33		JP I25	JP I24			Sequence groups 1 vs 3: 0.8% (5/622)
			JP I29				Sequence groups 1 vs 4: 0.6% (4/622)
			JP I30				Sequence groups 3 vs 4: 1.4% (9/622)
C	JP I93				JP I94		Sequence groups 1 vs 5: 0.5% (3/622)
	JP I95
	JP I99
	JP I100
D	valign="middle"JP I103
	JP I105
	JP I107
	JP I110
	(JP I109)b)

PCR products were directly sequenced, and the sequence data of the 622 bases of the PPV3 VP gene were subjected to a phylogenetic analysis. The “sequence group” in this analysis was defined by the phylogenetic branch (Fig. 1) and % nucleotide difference. In this table, nucleotide sequences in a box were identical, except for the JP I109 sequence of the sequence group 1 in farm D. a), In the “sequence group 1”, the JP I33 sequence of farm B was identical to the JP I109 sequence of farm D, which are located at the center of the phylogenetic tree of Fig. 2. The 4 sequences of farm C (JP I93, JP I95, JP I99 and JP I100) were identical, and the 4 sequences of farm D (JP I103, JP I105, JP I107 and JP I110) were also identical. The sequence of JP I33 and JP I109 differed by 2 bases from the 4 identical sequences of farm C and by 1 base from the 4 identical sequences of farm D. The 4 sequences of farm C and the 4 sequences of farm D differed by 3 bases. b), the JP I109 sequence was slightly different (0.2% (1/622)) from the other 4 sequences at the same farm.