Retroviral shuttle vectors as a tool for the study of mutational specificity (base substitution/deletion/mutational hotspot).

This paper summarizes the use of the retroviral shuttle vector pZipGptNeo for studies of mutational specificity in mammalian cells. This vector was constructed by the introduction of a DNA fragment containing the E. coli gpt gene into the retroviral shuttle vector pZipNeoSV(X)1. The pZipGptNeo vector was then introduced into mouse L cells to construct the A9I2 cell line. Studies utilizing the A9I2 cell line to determine the specificity of spontaneous and chemically-induced mutations are summarized. The construction of a new retroviral shuttle vector and its introduction into the CHO-K1 cell line is described. Preliminary experiments suggest that spontaneous gpt gene mutations arising in CHO cells are similar to those seen in the mouse L cells.