A Mouse Erythroleukemia Cell Line Possessing Friend Spleen Focus‐forming Virus gp55 Transgene and Temperature‐sensitive Mutant p53 Gene

Two different erythroleukemia cell lines have been established from the splenic lesions of transgenic mice possessing the Friend spleen focus‐forming virus (F‐SFFV) gp55 gene. One showed a neardiploid karyotype and a temperature‐sensitive (ts) p53 mutation, and the other, a hyper‐triploid karyotype with double p53 mutations found by single‐strand conformation polymorphism (SSCP) analysis. The cell lines both retained No.11 chromosomes on which p53 genes are localized. Another p53 allele in the cell line with the ts‐p53 mutation appeared intact in the SSCP analysis of the genomic exon 5. The cells with the ts‐mutant p53 gene showed no apparent change with temperature shift in their growth or dimethylsulfoxide‐induced differentiation, although the wild‐type p(53) gene on the other allele was not expressing. This ts‐p53(val‐135) gene made p53‐deficient fibroblasts anchorageindependent at 37°C but not at 32°C. This non‐virus‐producing, mouse erythroleukemia cell line will be useful for the study of mutated p53 function during the induction of erythrodifferentiation or apoptotic change.