Detection of deletion mutations in pSV2gpt-transformed cells.

AUTOR(ES)

Tindall, K R

RESUMO

We have developed a system to study mutations that affect xanthine-guanine phosphoribosyltransferase gene (gpt) expression in hypoxanthine-guanine phosphoribosyltransferase-deficient CHO cells that have been transformed by the plasmid vector pSV2gpt. One isolated transformant, designated AS52, carries a single copy of the Escherichia coli gpt gene stably integrated into the high-molecular-weight DNA and expresses the bacterial gene for the enzyme xanthine-guanine phosphoribosyltransferase. Mutants deficient in this enzyme can be induced in the AS52 cell line by a variety of mutagens, and spontaneous or induced mutants can be selected for resistance to 6-thioguanine (Tgr). Two Tgr clones derived from the AS52 line were analyzed by Southern blot hybridization and were found to contain deletions involving at least a portion of the gpt gene. Because of the small size and stability of the integrated pSV2gpt plasmid, and the well-defined selection protocol for mutant isolation, the AS52 line offers promise as a system suitable for the study of mutation at the molecular level in CHO cells.

Documentos Relacionados

• Transfection with plasmid pSV2gptEJ induces chromosome rearrangements in CHEF cells.
• Enhanced transformation of human cells by UV-irradiated pSV2 plasmids.
• Activation of infectious SV40 synthesis in transformed cells.
• pSV00CAT: low background CAT plasmid.
• The integrated state of viral DNA in SV40-transformed cells.