Nucleotide and deduced amino acid sequences of the matrix (M) and fusion (F) protein genes of cetacean morbilliviruses isolated from a porpoise and a dolphin ☆

Abstract

Morbilliviruses have been isolated from stranded dolphins and porpoises. The present paper describes the cloning and sequencing of the porpoise morbillivirus (PMV) F gene and of the dolphin morbillivirus (DMV) M and F genes and their flanking regions. The gene order of the DMV genome appeared to be identical to that of other morbilliviruses, A genomic untranslated region of 837 nucleotides was found between the translated DMV M and F gene regions. The predicted DMV M protein were highly conserved with those of other morbilliviruses. Both the deduced PMV and DMV F 0 proteins exhibited three major hydrophobic regions as well as a cysteine rich region, a leucine zipper motif and a cleavage motif allowing cleavage of the F 0 protein into F 1 and F 2 subunits. Apparently the DMV F 0 cleavage motif was not modified by adaptation of DMV to Vero cells. The predicted PMV and DMV F proteins were 94% identical. Comparisons with the corresponding sequences of other morbilliviruses demonstrated that the cetacean morbillivirus does not derive from any known morbillivirus but represents an independent morbillivirus lineage.