Sequence homology within the morbilliviruses

Abstract

Double-stranded c[complementary]DNA synthesized from total polyadenylate-containing mRNA extracted from monkey kidney cells infected with canine distemper virus (CDV) was cloned into the PstI site of Escherichia coli plasmid pBR322. Clones containing CDV DNA were identified by hybridization to a CDV-specific 32P-labeled cDNA. A cDNA clone containing an insert 1700 base pairs (CDV 364) was identified as the reverse transcript of the mRNA coding for the nucleocapsid protein. The size of the mRNA species complementary to this insert is 1850 nucleotides, as determined by the Northern technique. Hybridization experiments and heteroduplex mapping indicated homology between the central region of the CDV and measles virus nucleocapsid gene. The completion of the nucleotide sequence analysis of the measles virus gene allowed the reconstruction of the entire coding region of the measles virus gene and a comparison with the counterpart sequence of CDV. This comparison delineated 3 regions: a region of high homology (nucleotides 501 .+-. 1215), in which 77% of the nucleotides and 88% of the encoded amino acids are identical; a region of moderate homology at the 5'' end of the message (nucleotides 1-500), in which 59% of the nucleotides and 66% of the encoded amino acids are identical; a region of little or no homology (nucleotides 1216-1625) near the 3'' end of the message.