Abstract |
The TK+/- 3.7.2C cell line contains chromosomes 11 of normal morphology when investigated by high resolution banding techniques. In the mouse TK-1 has previously been mapped by somatic cell genetics to chromosome 11. The sublocalization of the break points in chromosome 11 deletions, translocations, and insertions occurring in induced TK-/- mutants was investigated. An acridine orange/Colcemid/hypotonic treatment of TK-/- mutants was developed to provide high resolution chromosomes with over 500 G-bands for break point analysis. Using both standard and high resolution procedures, independently induced small colony mutants show rearrangements in the distal portion of chromosome 11, with break points occurring between bands B5 and D1.3. This finding of a range of chromosomal break points in different TK-/- mutants is consistent with the hypothesis that chromosomal lesions occurring in small-colony mutants may affect a large portion of the genome in the vicinity of the TK gene, and with recent molecular genetic analysis of mutants. (Copyright (c) 1989 Elsevier Science Publishers B.V. (Biomedical Division).) |