CYTOGENETIC STUDIES OF CELL-LINES DERIVED FROM MAREKS-DISEASE VIRUS-INDUCED LOCAL LESIONS

Cytogenetic analysis of cell lines derived from Marek's disease virus (MDV)-induced local lesions was performed to detect the presence of a chromosomal alteration found previously in eel lines derived from MDV- induced visceral tumors. This chromosomal alteration involves an ampli fied region on the short arm of chromosome 1. Trypsin G-banding was pe rformed on 12 local-lesion cell lines having various T-cell receptor p henotypes. Eight of 12 cell lines had a diploid female karyotype, and four lines were diploid males. Ten of the cell lines showed a normal G -banding pattern; two lines, however, had the short arm amplification on chromosome 1 (1p+). Thus, the 1p+ alteration does not appear to be necessary for establishment of cell lines from local lesions. The occu rrence of the 1p+ alteration in Marek's disease cell lines suggests a possible role for this alteration in late stages of multi-step viral o ncogenesis.