Evidence for phenotypic mixing with reovirus in cell culture.

From pairwise mixed infections of different reovirus wild-type isolates (T3 Dearing plus T1 Lang or plus T2 Jones) the progeny virus is phenotypically mixed, i.e., progeny viral particles contain proteins derived from both parents but the corresponding genes derived from only one parent. Experiments with differential inactivation of virus progeny of mixed infections by monoclonal antibodies or by 33% ethanol reveal phenotypic mixing of two outer shell proteins, sigma 1 and probably mu 1. Phenotypic mixing of the mu 1 protein, the product of the M2 gene, is a possible explanation for the recent observation of M2 gene-linked dominant interference between reovirus isolates.