Abstract
Methylation of Marek's disease virus serotype 1 (MDV1) DNA in both productively and latently infected cells was examined by restriction endonuclease analyses with the isoschizomeric pair HpaII and MspI. The latent MDV1 DNA in T-lymphoblastoid cell lines established from chicken T-lymphomas was considerably methylated, whereas methylation of the virus DNA sequences was not detected in productively infected cells.