Deoxyribonucleic Acid of Marek's Disease Virus in a Lymphoblastoid Cell Line from Marek's Disease Tumours

Cellular oncogenes (c-erb-A and c-erb-B) located on different chicken chromosomes can be transduced into the same retroviral genome.

“…These findings conflict in part with results obtained by hybridization in situ, which located cmyc, c-myb, and both c-erb loci on small chromosomes or microchromosomes (27,28,30). It has been suggested that these discrepancies arise from the fact that the MSB-1 cell line generally used for fractionation of chicken chromosomes (15,17) Bishop, unpublished data). It therefore appears safe to conclude that in chickens, as in other species (4), cellular oncogenes are dispersed among multiple chromosomes and that on several occasions two of these dispersed genes, c-erb-A and c-erb-B (29), c-myc and c-mil (also termed c-mht) (11,12), or c-mvb and c-ets (14,16), have been transduced into the genome of a single retrovirus.…”

“…Chromosomes were fractionated by sucrose gradient centrifugation (10,17); two chromosome gradients from the MSB-1 lymphoid line (15) were examined, and similar results were obtained with both. The results presented in Fig.…”

The ultrastructure of lymphoblastoid cell lines from Marek's disease lymphomata

“…The main difference between the two cell lines is the presence of prominent nucleoli in the Burkitt's cells, both at the light and electron microscope levels Epstein andAchong, 1965, 1970) (Miller, Stitt and Miller, 1970) aand it has been suggested that EBV7 infection may be a prerequisite for the permanent growth of h-uman lymphoblastoid cell lines in vitro (Nilsson et al, 1972). A similar situation may also occur in AMarek's disease, since recently, Nazerian (Nazerian et al, 1973;Nazerian and Lee, 1975 (Mladenov et al, 1972;Doak, Alunnell and Ragland, 1973;Frazier, 1974). The presence of nuclear projections has been reported in the lymphoid cells of other neoplasnms including Burkitt's lymphoma (Achong and Epstein, 1966;Papadimnitrion, 1966;AMollo and Stranignoni, 1967;Parker, Wakasa and Lukes, 1967;Miller et al, 1969).…”

Nucleosomal Structure of Marek's Disease Virus Genome in Transformed Lymphoblastoid Cell Lines, MDCC‐MSB1 and MDCC‐RP1

“…Although the established lymphoblastoid cell lines contain multiple copies of MDV genomes, they appear to be virus-nonproducers (8) and transcription of MDV DNA in latently infected lymphoblastoid cells is restricted to a portion of the viral genome (13,24,26,29). The viral particles can be rescued from most of these MDV-derived lymphoblastoid cells by cocultivation with susceptible cultured cells or by inoculating them into chickens (8) and an expression of viral antigen is stimulated by the treatment of these cells with IUdR (20). Thus, the maintenance of latency seems to involve mechanisms regulating viral transcription.…”