Observations on the morphology of two rotaviruses.

The negative staining technique was used to study the morphology of two rotaviruses, the epizootic diarrizootic diarrhoea of infant mice (EDIM) and the simian virus SA II. It is proposed that the inner capsid of the virion has icosahedral symmetry and consists of 180 morphological units arranged in an open lattice formation with the 12 spaces at the apices being surrounded by 5 capsomeres and the other 80 spaces each surrounded by six capsomeres. The outer capsid of the virion consists of a honeycomb-like lattice which corresponds to the lattice arrangement of the inner capsid.