Identification and transcriptional analysis of the homologues of the herpes simplex virus type 1 UL41 to UL51 genes in the genome of nononcogenic Marek's disease virus serotype 2.

Studies on Marek's disease virus serotype 2 (MDV2) are important for understanding the natural nonpathogenic phenotypes of MDV. We determined the 16770 bp nucleotide sequence of the MDV2 genome located in the right part the of unique long region. The analysis revealed 12 complete open reading frames (ORFs) with high amino acid sequence identities to the gene products of other alphaherpesviruses. The MDV2 ORFs were arranged collinearly with the prototype sequence of herpes simplex virus type 1 ranging from the UL41 to UL51 genes. Except for the MDV2 UL41 gene, all of the identified genes were confirmed to be transcribed with 3'-coterminal mRNAs and/or a unique transcript in the virus-infected cells. Transcriptional patterns for the regions of the MDV2 UL48 to UL49.5 genes were notably different from the similar area of MDV serotype 1.