NUCLEOTIDE-SEQUENCE OF THE GLYCOPROTEIN-C (GC) HOMOLOGOUS GENE OF MAREKS-DISEASE VIRUS (MDV) SEROTYPE-2 AND COMPARISON OF GC HOMOLOGOUS GENES AMONG 3 SEROTYPES OF MDV

The sequence analysis of the genomic region of Marek's disease virus ( MDV) serotype 2 (MDV2) which had homology with the gene encoding MDV s erotype 1 (MDV1) homologue of glycoprotein C (gC) of herpes simplex vi rus revealed that there was a single open reading frame (ORF) capable of encoding 479 amino acids. The predicted protein from this ORF had s trong hydrophobic regions in both the amino and carboxyl termini and s everal potential N-linked glycosylation sites, as seen in those from t he ORFs of MDV1 and MDV serotype 3 (MDV3 = herpesvirus of turkeys (HVT )) gC homologues. By northern-blot analysis using a DNA fragment locat ed in the MDV2 gC homologue ORF as a probe, 3.6 and 1.9 kb RNA transcr ipts were identified in MDV2,-infected cells. When the alignment of am ino acid sequences of the gC homologous genes of three MDV serotypes w ere compared, the homology between MDV1 and MDV2 and that between MDV1 and HVT showed about 76% identity, whereas that between MDV2 and HVT was about 70% identity. These results suggested a possibility that the evolutionary distance between MDV1 and MDV2 and between MDV1 and HVT is shorter than that between MDV2 and HVT.