Tissue tropism of avian reoviruses is genetically determined

Two genome segments, M2 and S1, were preferentially selected in reassortant s isolated in Vero cells. Analysis with monoclonal antibodies (MAbs) agains t RAM-1 strain showed that the 39-kDa protein encoded by the genome segment S1 contained epitopes involved in neutralisation of virus infectivity for both Vero and chicken kidney (CK) cells. The 39-kDa protein appeared to hav e two major epitopes that are attachment sites for cell receptors, one inte racting only with CK cell receptors and the other with both CK and Vero cel l receptors but principally Vero cell receptors. These results suggest that the strain RAM-1 may have developed an epitope for Vero cell receptors owi ng to mutation in the SI genome segment, but still retained the epitope res ponsible for infection of CK cells. (C) Inra/Elsevier, Paris.