The molecular basis of the antigenic variation of foot-and-mouth disease virus.

Abstract
We have cloned and sequenced the viral protein (VP1)‐coding regions of two foot‐and‐mouth disease virus (FMDV) serotypes (C1 and A5). Comparison of the derived amino acid sequences with the known VP1 sequence of FMDV O1K and the two FMDV A subtypes A10 and A12 shows two highly variable regions in the protein, at positions 40‐60 and 130‐160, as possible antigenic sites. In both variable regions, several sites could be detected where all three sequences of the A subtypes are identical but the three types A, C and O differ from each other. The second variable region overlaps with a major immunogenic determinant of the virus.