SIGNIFICANCE OF MAREKS-DISEASE VIRUS SEROTYPE 1-SPECIFIC PHOSPHORYLATED PROTEINS IN MAREKS-DISEASE SKIN-LESIONS

Skin tissues were obtained from 12 chickens showing Marek's disease (M D) skin tumour induced by a very virulent MD/5 strain of Marek's disea se virus serotype 1 (MDV1) and taken from 24 field broiler chickens (8 to 9-weeks-old) manifesting MD skin tumour. They were examined by the immunohistochemical method in order to examine the topographic expres sion of MDV1-specific phosphorylated proteins (PP) and by the reverse- transcription polymerase chain reaction following Southern hybridizati on to analyse their gene transcriptional activity. PP were massively d etected and their gene transcripts were abundantly expressed only in t he necrotic areas of some experimentally-induced MD cutaneous lymphoma lesions. Strong PP-positive cells were degenerate or necrotic lymphob lasts. The other field or experimentally-induced MD cutaneous lymphoma lesions, even those consisting almost completely of tumorous lymphobl asts, had only a few PP-positive lymphoid cells and few gene transcrip ts. Necrotic areas of feather pulp MD lymphoma lesions consisting main ly of degenerate or necrotic lymphoblasts and cytolycic feather follic le epithelium (FFE) were also strongly positive for PP. PPs and their gene transcripts were detectable only in the cytolytically infected ce lls such as FFE and tumorous lymphoblasts converting to the abortic st ate.