Assembly of double-shelled rotaviruslike particles by simultaneous expression of recombinant VP6 and VP7 proteins.

Simultaneous coinfection of Spodoptera frugiperda cells with baculovirus recombinants containing the genes for VP6 and VP7 of bovine rotavirus strain C486 resulted in the production of spherical particles resembling smooth, double-shelled rotavirus. These particles were predominantly located in the cell culture supernatant instead of being cell associated. Pretreatment of infected-cell culture supernatants with CaCl2, prior to particle purification, was found to enhance the smooth appearance of the particles. The authenticity of the proteins making up the particles was demonstrated by their reactivity with antiserum specific for double-shelled C486 rotavirus.