SEQUENCE OF THE S-FRAGMENT OF FOOT-AND-MOUTH-DISEASE VIRUS TYPE A(12)

The foot-and-mouth disease virus (FMDV) genome contains a 5' untransla ted region (S fragment) capable of forming a stem-loop structure of ov er 350 bases, which is separated from the remainder of the genome by a homopolymeric cytidylic acid tract (poly(C)) of variable length. The sequence of the S fragment of serotype Al? appears more similar to tho se of type O-1 or type C-3 than to subtype A(10). The relatively large difference between the S fragment sequences of two type A viruses sug gests that the sequences per se of this region of the genome are not c ritical for the maintenance of function, and suggests the possibility of a relatively recent recombination event within the poly(C) region o f the A(12) genome.