Sequences of three complete genomes of HRV were obtained for strains N4 (reference R3061207002 collected on December 7, 2006) , N10 (R3070614001 collected on June 14, 2007) and N13 (R3070719007 collected on July 19 2007). Primers used for the amplification of viral genomes were designed after multiple alignments of sequences from the genomes of different HRVs available in GenBank (Table 1) . Overlapping amplified DNA products were obtained after PCR of cDNA that was obtained using oligodT and a Transcriptor High Fidelity cDNA Synthesis Kit (Roche, Mannheim, Germany), following the manufacturer's protocols. Briefly, 10.4 ml viral RNA was mixed with 1 ml oligodT and heated at 65uC for 10 min, and then kept on ice for 2 min. After addition of 4 ml 56buffer, 0.5 ml Protector RNase Inhibitor, 2 ml dNTPs, 1 ml DTT, and 1 ml RT enzyme, the reaction was incubated at 50uC for 1 h, inactivated at 85uC for 5 min, and stored at 220uC. Amplification of a 3D region of N4, N10 and N13 HRV strains was carried out by nested-PCR using Takara EXTaq (Takara Biotechnology) and specific primers (Table 1) , for 35 cycles of 30 s at 94uC, 30 s at 55uC, and 70 s at 72uC. To amplify VP1 (upstream of 2A) sequences of N4 and N13 strains, nested PCR was carried out using Takara LATaq with GC buffer I(Takara Biotechnology), specific primers (Table 1) , and incubation for 35 cycles of 30 s at 94uC, 30 s at 60uC, and 4 min at 68uC. The fragment VP2-3D of N10 HRV strain was obtained by seminested PCR and specific primers VP2 F, and 3D inner and outer reverse primers (Table 1) , using Takara LATaq with GC buffer II, for 35 cycles of 30 s at 94uC, 30 s at 60uC, and 6 min at 68uC. The terminal part of the whole genome was obtained by rapid amplification of cDNA ends using 59/39 rapid amplification of the cDNA kit, following the manufacturer's protocol (Roche). To perform 59 terminal RACE, 4 ml of 56cDNA buffer, 2 ml dNTPs, 1.25 ml specific primer 1 (10 mM), 9.2 ml RNA, 1 ml control primer neo1/rev (12.5 mM), 1 ml control RNA, 1 ml RT enzyme, and 0.6 ml RNase inhibitor (Roche) were mixed and incubated for 55uC for 60 min, followed by inactivation at 85uC for 5 min, and stored on ice. The product was purified using the Qiagen PCR Purification Kit and eluted with 30 ml deionized distilled water. A polyA tail was added to the cDNA, by mixing 9.5 ml DNA with 1.25 ml 106 reaction buffer, 1.25 ml (2 mM) dATP, and after incubation at 95uC for 3 min, the reaction was chilled on ice for 2 min. After addition of 0.5 ml terminal transferase, the reaction was incubated at 37uC for 30 min, inactivated at 70uC for 10 min, and kept on ice. Nested PCR was performed by using the Expend High Fidelity PCR kit (Roche). A mixture of 2.5 ml poly-dA-tailed cDNA, 0.5 ml oligodT-anchor primer 37.5 mM, 0.62 ml SP2 primers (10 mM) (Table 1) , 0.5 ml control neo2/rev primer (12.5 mM), 0.5 ml dNTP, 0.35 ml enzyme, 2.5 ml 106 buffer, and 18 ml ddH 2 O was incubated for 40 cycles of 30 s at 94uC, 30 s at 60uC, and 30 s at 72uC. To perform 39 terminal RACE, the method was similar to normal two-step RT-PCR using 3D inner and outer F primers (Table 1) .