Isolation by polymerase chain reaction of a cDNA whose product partially complements the ultraviolet sensitivity of xeroderma pigmentosum group C cells

A xeroderma pigmentosum (XP) cell line from complementation group C has been complemented to attain ultraviolet (UV) resistance and DNA repair proficiency, by transfection with a human expression cDNA library, followed by selection to UV resistance. We now show that the transfected cDNAs can be rescued from cellular DNA of a secondary transformant by its in vitro amplification using expression-vector-specific oligodeoxyribonucleotides as primers in a polymerase chain reaction. The amplified cDNAs were cloned into a mammalian expression vector. Their transfection into XP cells identified a single cDNA which specifically complemented the UV sensitivity of a group-C-derived cell line to the same partial UV-resistance levels exhibited by the transformant from which the cDNAs were rescued.