02100naa a2200181 a 450000100080000000500110000800800410001902200140006010000160007424501590009026000090024952015280025865000140178665300240180070000150182470000150183977300640185416331511995-05-02       1994    bl uuuu     u00u1 u    #d  a0331-949X1 aWANG, C. H.  aComparison of the nuclear inclusion b protein and coat protein genes of five papaya ringspot virus strains distinct in geographic origin and pathogenicity  c1994  aA complementary DNA library was construced to the genomic RNA of an isolate of papaya ringspot virus (PRSV), PRSV YK (YK), that represents the most prevalent mosaic strain of Taiwan. A 2.96-kb clone, pYKB9, corresponding to the 3'-region of YK RNA was selected by immunoscreening with the antiserum to the coat protein (CP). The clone had 2,960 nucleotide residues and represented part of the nuclear inclusion a (NIa) gene, the complete nuclear inclusion b (NLb) gene, the entire CP gene, and the 3'-noncoding region of YK RNA. The nucleotide sequence was compared to those of the 3' regions of the published Hawaii severe strain, PRSV HA (HA), the Hawaii mild strain PRSV HA 5-1 (HA 5-1), the nonpapaya-infecting Florida strain, PRSV W(fl) (W(fl)), and the nonpapaya- infecting Australia strain PRSV W(aust)). The NIb region had 83.1% nucleotide identy and 95.7% amino acid identity compared to that of HA, with a total of 262 nucleotide differences resulting in only 22 amino acid changes. A similiar trend also was found whwen the NIb region of YK was compared to the partially elucidated NIb regions of HA 5-1 and PRSV W(fl), with 84.7% and 85.2% nucleotide identities (147 and 151 nucleotide differences), respectively: both resulting in 97.6% amino acididentily (only eight amino acid changes). Most of the nucleotide differences between the Asian and American strains occurred in wobble basesand, thus, conserved the amino acid residues, suggesting a common selection pressure to keep the same protein conformation.  aPotyvirus  aAmino acid sequence1 aBAU, H. J.1 aYEH, S. D.  tThe American Phytopathological Societygv. 84, n. 10, 1994.