Mosaic structure of foot-and-mouth disease virus genomes.

The results of a simple pairwise-scanning analysis designed to identify inter-serotype recombination fragments, applied to genome data from 156 isolates of Foot-and-mouth disease virus (FMDV) representing all seven serotypes, are reported. Large numbers of candidate recombinant fragments were identified from all parts of the FMDV genome, with the exception of the capsid genes, within which such fragments are infrequent. As expected, intertypic fragment exchange is most common between geographically sympatric FMDV serotypes. After accounting for the likelihood of intertypic convergence in highly conserved parts of the FMDV genome, it is concluded that intertypic recombination is probably widespread throughout the non-structural genes, but that recombination over the 2B/C and 3B/C gene boundaries appears to be less frequent than expected, given the large numbers of recombinant gene fragments arising in these genes.