Identification of the porcine cytomegalovirus major capsid protein gene

A major capsid protein (MCP) gene homologue of porcine cytomegalovirus (PCM V) was identified. Sequence analysis indicated that the PCMV MCP gene is 4, 026 nucleotides in length encoding a protein of 1,341 amino acid residues. The predicted molecular weight of the PCMV MCP is 151,456 Da, equivalent to those of other herpesvirus MCP counterparts. Phylogenetic analysis using h erpesviral MCP gene sequences confirmed that PCMV is a betaherpesvirus with higher homology with human herpesvirus-6 and -7 than human and mouse cytom egaloviruses. The serum of pig experimentally infected with PCMV did not re act with bacterially expressed MCP, suggesting that the PCMV MCP may not be related to the humoral immune response in the course of PCMV infection. Al so, we established polymerase chain reaction (PCR) protocols using primers corresponding to MCP gene sequences fur detection of PCMV infection. The PC R protocol would be effective for the diagnosis of slow-growing PCMV infect ion, for which traditional methods involving virus-isolation are not useful .