Nucleotide sequences and expression in Escherichia coli of the coat protein genes from two strains of melon necrotic spot virus.

The nucleotide sequences of coat protein (CP) genes of two Japanese strains of melon necrotic spot virus (MNSV-NH and MNSV-S) were determined. The size of the CP genes of both strains was 1170 nucleotides. Comparisons of the deduced amino acid sequences among MNSV strains showed more than 95% homology, and those among other carmoviruses showed 31-34% homology. cDNAs of MNSV CP genes were cloned into an Escherichia coli expression fusion vector and MNSV-NH and MNSV-S CPs were successfully produced. Furthermore, synthetic oligonucleotide primers were used for differentiating MNSV strains by reverse transcription-polymerase chain reaction method.