The avian rotavirus Ty-1 Vp7 nucleotide and deduced amino acid sequences differ significantly from those of Ch-2 rotavirus

Abstract

The Vp7 gene of the avian strain Ty-1, which is classified as G7 serotype, was sequenced and the amino acid sequence deduced. The gene is 1065 nucleotides long with a long open reading frame of 987 nucleotides producing a protein 329 amino acids in length. The amino acid homology of the Ty-1 Vp7 protein to that of the avian Ch-2 Vp7 was 70%. The A, B, and C variable epitope regions of Ty-1 were unique compared to those of Ch-2 and other strains representing the 14G serotypes. The low 53% homology of the A and C regions of Ty-1 and Ch-2 would suggest that Ty-1 may be of a different serotype to the G7 reference strain Ch-2.

Full Genome-Based Classification of Rotaviruses Reveals a Common Origin between Human Wa-Like and Porcine Rotavirus Strains and Human DS-1-Like and Bovine Rotavirus Strains

“…Since the avian rotavirus strain Ch-2 (56) was the first G7 rotavirus to be characterized and sequenced, it should remain as the prototype genotype G7 avian strain, along with the avian strain Ty-3 (Ͼ99% nucleotide identity with Ch-2). Avian rotavirus strain Ty-1 (69 to 78% nucleotide identity with other avian strain) can tentatively be assigned to a new genotype, G17 (32). The pigeon rotavirus strain PO-13 and the avian-like bovine rotavirus strain 993/83 (65) (Ͼ95% nucleotide identity with PO-13) may be assigned to new genotype G18, while avian strain Ch-1 (47) (67 to 74% nucleotide identity with other avian strain) may be assigned to new genotype G19.…”

Characterization of neutralization epitopes on the VP7 surface protein of serotype G11 porcine rotaviruses

“…Cross-neutralization analysis of the escape mutants of strain A253 and the respective MAbs used for their selection suggested the presence of two non-overlapping epitopes that, by sequence analysis, were related to substitutions in region A and C. One epitope was defined by MAb 8D10 which selected a mutation at position 223 (region C) where the corresponding amino acid is conserved among all rotavirus strains described to date (Green et al, 1987;Estes & Cohen, 1989;Huang et al, 1989;Nishikawa et al, 1989Nishikawa et al, , 1991Taniguchi et al, 1990;Browning et al, 1991a, b;Kool & Holmes, 1993). To explain the serotype-specific neutralization reactivity of this MAb, the involvement of at least one other amino acid residue, probably in region C, might be required.…”

“…The VP7 sequences of strains SA11 (Nishikawa et al, 1989), OSU (Gorziglia et al, 1986), ST3 (Green et al, 1987) and YM (Ruiz et al, 1988) were previously published. The amino acid at position 12 of the clonal stock of strain YM was found to be phenylalanine and a nucleotide change at position 382 (T to G) resulted in a switch from serine to proline (data not shown), which is conserved in all other rotavirus serotypes sequenced to date (Green et al, 1987;Estes & Cohen, 1989;Huang et al, 1989;Nishikawa et al, 1989Nishikawa et al, , 1991Taniguchi et al, 1990;Browning et al, 1991 a, b;Kool & Holmes, 1993 YM < 100 < 100 < 100 < 100 51200 102400 6400 YM 5E6.1t < 100 < 100 < 100 YM 5E6.5t < 100 < 100 800 YM 8E8 < 100 < 100 400 A253 51200 3200 1600 51200 102400 102400 102400 A253-6E10 < 100 < 100 < 100 < 100 < 100 800 102400 A253 3C8 < 100 < 100 < 100 < 100 < 100 1600 12800 A253-7D9 < 100 < 100 < 100 < 100 < 100 800 51200 A253-7F10 < 100 < 100 < 100 < 100 < 100 400 51200 A253-8E8 < 100 < 100 < 100 < 100 < 100 800 51200 A253-5E6 < 100 < 100 < 100 < 100 < 100 400 51200 A253-8D10 25600 6400 3200 25600 51200 102400 < 100 * Neutralization titres are expressed as the reciprocal of the highest dilution of ascitic fluid that reduced the fluorescent focus count by more than 66%. Significant neutralization titres are indicated in bold.…”

Viral Enteric Infections

“…The nature of protective immunity in recovered birds is not fully understood. Specific secretory IgA, humoral, and T-cell mediated immunity have been demonstrated in recovered turkeys (28,50,51,(56)(57)(58)(59). Specific secretory IgA was shown to persist in intestinal secretions and bile of recovered turkeys for at least six months (56).…”

“…Specific secretory IgA, humoral, and T-cell mediated immunity have been demonstrated in recovered turkeys (28,50,51,(56)(57)(58)(59). Specific secretory IgA was shown to persist in intestinal secretions and bile of recovered turkeys for at least six months (56). Concentrations of specific secretory IgA antibodies in feces of TCV-infected turkeys peaked at 3-4 weeks PI and disappeared at approximately 6 weeks PI (51).…”