A comparison of the structural polypeptides of three iridescent viruses (types 6, 9, and 16) and the mapping of the DNA region coding for their major capsid polypeptides.

The iridoviruses from Wiseana cervinata (WIV, type 9), Costelytra zealandica (CzIV, type 16) and Chilo suppressalis (CIV, type 6) were compared by SDS-PAGE and Western protein blotting for antigenic determinants. The major capsid proteins were isolated and oligonucleotide probes were synthesized from the partial amino acid sequences. The DNA regions coding for the major capsid proteins of WIV (VP52), CzIV (VP53) and CIV (VP50) were located by hybridization of the oligonucleotide probes to blots of the viral DNA. The major capsid protein was used as the zero point for the proposed linearized maps of these viruses. Using antibody and 125I-labelling, several proteins were identified as being on the surface of the virion. It was also shown that CIV was not as antigenically distinct from these two viruses as previously reported.