Immunoblot analysis of gH/gL complexes in parental viruses and TR-ME heterologous gO recombinants. Extracellular virion extracts of TR, TR_MEgO, ME, ME_TRgO, ME-T, or ME-T_TRgO were separated by reducing (A and B) or nonreducing (C) SDS-PAGE and analyzed by immunoblot probing for major capsid protein (A) or gL (B and C).