Multicolor spectral karyotyping of the L5178Y Tk+/- -3.7.2C mouse lymphoma cell line.

The L5178Y/Tk+/- -3.7.2C mouse lymphoma cell line is characterized, at the cytogenetic level, by a karyotype involving both numerical and complex structural aberrations. While the karyotype is remarkably normal for a transformed cell line that has been in culture for almost half a century, there are a number of chromosomal alterations that because of their complexity cannot be fully characterized by routine or even high-resolution G-banding studies. Multicolor spectral karyotyping (SKY) was performed on the cell line in anticipation of identifying the previously unresolved chromosome aberrations and confirming interpretations previously identified by banding studies. New chromosome aberrations detected by SKY include numerical aberrations of chromosome 15, duplications of regions of chromosomes 4, 5, 12, and 18, and deletion of chromosome 14. Complex unbalanced translocations involved segments of chromosomes 6, 14, and 15. In total, the SKY technique was able to provide new refined designations on segments of eight different chromosome pairs (4, 5, 6, 9, 12, 14, 15, 18) and identified all three previously unidentified marker chromosomes. This analysis provides an updated standard reference for the karyotype of the L5178Y/Tk+/- -3.7.2C cell line used in the in vitro mouse lymphoma mutation assay.