L5178Y TK+/- Clone (3.7.2C) Cells

The L5178Y TK+/− Clone 3.7.2C cell line is a mouse lymphoma model widely used for in vitro genotoxicity testing, particularly in the mouse lymphoma thymidine kinase (TK) gene mutation assay (MLA). This clone was derived from the parental L5178Y cell line, established from a thymic lymphoma induced by methylcholanthrene in DBA-2 mice. The 3.7.2C subclone was specifically developed to be heterozygous at the TK locus (TK+/−), enabling the selection of TK−/− mutants through loss-of-heterozygosity events.

L5178Y TK+/− 3.7.2C cells are characterized by their rapid population doubling time (approximately 8-11 hours) and stable modal chromosome number of 40. They exhibit a complex karyotype including Robertsonian fusions and specific translocations. The p53 gene is mutated in these cells, with one allele carrying a nonsense mutation in exon 4 and the other a missense mutation in exon 5, resulting in the loss of normal p53 function. This genetic background enhances their utility for studying clastogenic and mutagenic effects.