Granzow, C. and Nielsén, K, 1984. A genome mutation in three related sublines of the Ehrlich‐Lettré mouse ascites tumor. —Hereditas 100:93–110. Lund, Sweden. ISSN 0018–0661. Received May 30, 1983
Whilst the Gø subline of the Ehrlich‐Lettré mouse ascites tumor (ELAT) corresponds phenotypically and cytogenetically to H. Lettrés original tumor subline, the three colchicine resistant, glycogen‐storing ELAT sublines, CR, G+, and HD33, differ from it by: (1) A reduction in stemline numbers from 46 to 40 or 41, (2) the existence of only three minute marker chromosomes, (3) the presence of a specific marker chromosome, marAB, and (4) the activity of essentially only one very large NOR, located on marAB.
The reduction in stemline numbers is not paralleled by a decrease of the average cellular DNA content, which seems to be influenced more by cell kinetic factors than by the levels of the stemline number.
Only minor but constant karyotypical differences exist between the CR and the closely related G + and HD33 sublines. G‐band patterns indicate the origin of marAB from a centric fusion between marA and the q arm of marB present in Gø ascites cells.
The genome mutation of the CR subline is probably due to the action of N‐methylcolchicamide (H LETTRÉ and W. KRAMER, Naturwissenschaften 39, 117, 1952). The artificial presence of such mutant cells with altered phenotype in other ELAT sublines may cause misleading experimental results and should he carefully excluded.