Cytochemistry, Cytogenetics and Ultrastructure of Hamster Tumour Cells Carrying Mouse Sarcoma Viral Genome (HT-1 Cells)

The pleomorphic cytology of the HT-1 cell line is described. Cytochemical studies indicated the presence of glycogen and lysosomes in these cells. Cytogenetic studies demonstrated the presence of a large telocentric chromosome (M1) and two minute chromosomes (M2) not found in normal hamster cells. A cloned line was isolated which did not contain these marker chromosomes. All cells were hyperdiploid with chromosome number around triploidy, although none was a true triploid. Ultrastructural studies revealed the presence of "nuclear bodies", "dense bodies" and "interchromatinic granules" which have been previously described in viral induced malignancies. A few of the cells contained in their cytoplasm structures of approximately 700 [unk] in diameter which bore some resemblance to immature virus particles. Both light and electron microscopy demonstrated some nuclei lacking chromatin aggregates. This is interpreted to mean that the total genetic material of these nuclei was dispersed as free DNA not linked with histone to form chromatin aggregates.