Cytogenetic studies of a simian virus 40 temperature-sensitive mutant-transformed Chinese hamster cell clone at the permissive and nonpermissive temperature.

A clone of Chinese hamster embryo cells transformed by tsA58, the temperature-sensitive mutant of simian virus 40, was analyzed for chromosome abnormalities at the permissive temperature (37 degrees C) and nonpermissive temperature (40.5 degrees C). Trypsin-Giemsa-banded metaphases were analyzed 1 week after the temperature shift. The metaphases from cells at both temperatures were pseudodiploid, with numerous chromosome changes primarily affecting chromosomes no. 1 and 2. Other chromosomes (no. 6, 11, and the X) were also frequently involved. A marker chromosome, LM, was present in 35% of the cells at 40.5 degrees C.