Diploidy and Heteroploidy in Cultured Cells Derived from New Zealand Rabbits

抄録

The chromosome complement and the incidence of polyploidy, sex chromatin and chromosome aberrations were analysed in primary kidney and lung cells from the rabbit (Oryctolagus cuniculus) and in two continuous cell lines (E4L1 and E4L2) initiated from embryonic lung tissue.
Chromosome polymorphism in the short arm of pair 11, probably produced by chromosome contraction because of colcemid treatment, was found in primary and cultured cells. Primary cultures showed 0-25% aneuploid metaphases and 0-4% chromosome aberrations. Polyploidy ranged from 6-14% in epithelial-like primary cultures and 1-3% in fibroblast-like primary cultures. Sex chromatin in female cells ranged between 5-42% depending on whether the studies were performed on non-confluent cultures (lowest percentage) or confluent cultures (highest percentage).
Chromosomal analysis on passage 10, 29, and 34 of the E4L1 line showed a progressive increase in the polyploid index (2% in passage 10, 15% in passage 34); the percentage of cells with normal karyotype varied from 85-90%.
Two different series of cultures of the line E4L2 behaved similarly: they were diploid up to passage 20 and suddenly became hyperdiploid between passages 21-25.
A comparison of the karyology of primary and cultured cells allowed one to suggest that the definition of diploidy for cultured cells should be based on: a) karyological analysis of successive cell samples of the same line separated by approximately 10 passages, b) comparison of the karyology of cultured cells with the karyology of primary cultures from which the line was initiated.