Molecular characterisation and identification of the major immediate-early (MIE) genes of rat cytomegalovirus (RCMV)

Abstract

The paper first describes the characterisation and identification of two transcripts of major immediate-early (MIE) genes of rat cytomegalovirus (RCMV) strain ALL-03 using molecular approach. In the absence of any known sequences in the strain ALL-03, IE genes, the first recognised viral genes expressed during infection were the most important genetic source for the exploration of the viral genome. The steps taken were the construction of cDNA libraries from rat embryonic fibrolast (REF) infected with RCMV strain ALL-03 under 'IE' condition by using several techniques such as RT-PCR, PCR, cloning, sequencing and bioinformatics. Two transcripts were confirmed to be of RCMV strain ALL-03 origin by specific PCR and hybridisation analyses. Based on the bioinformatics analyses, it is most likely, that these transcripts are exon 4 (IE1) and exon 5 (IE2) genes. The considerable divergence in the nucleotide sequence of the two IE transcripts from those of MIE regions of both Maastricht and English strains further supports the claim that the ALL-03 is a distinct RCMV strain indeed.