Gel electrophoretic analysis of polypeptides from nucleocapsids of Marek's disease virus strains and herpesvirus of turkey.

The polypeptides of nucleocapsids of Marek's disease virus (MDV) strains with different biological properties and of antigenically related herpesvirus of turkey (HVT) strains were analysed by one- and two-dimensional (1D and 2D, respectively) gel electrophoresis. Based on small differences in migration behaviour (size and charge) of a number of corresponding nucleocapsid polypeptides, the virus strains could be differentiated into three groups. The polypeptide pattern of group I, comprising the virulent MDV-strain K and the attenuated strains, HPRS-16/att and CVI988 37th passage, was composed of four major polypeptides (i.e. 140K, 50K, 40K and 33K daltons) and at least four minor polypeptides. The pattern of group II, comprising the naturally occurring non-oncogenic MDV-strains SB-1 and HPRS-24, contained one additional major polypeptide of 39K daltons. The nucleocapsid-specific 2D polypeptide patterns of the HVT strains HVT-Fc 126 and PB-THV1, comprising group III, were distinguishable from each other on the basis of a small difference in size of one major 50K polypeptide. Results were further substantiated by coelectrophoresis experiments.