<正>Objective:To explore the role of transcription-coupled repair （TCR） pathway in the UVC-induced SupF gene mutation in Tet-on 293 cell line

we designed and constructed a Tet-responsive plasmid DNA pTCR-C1

and utilized this pTCR-C1 plasmid to obtain the mutation frequency of SupF reporter gene induced by UVC in Tet-on 293 cell line. Methods:SupF gene was cloned into a Tet-responsive plamid pBI-L

which include a bidirectional Tet-responsive promoter

and was named pTCR-C1.The pTCR-C1 plasmid was transfected into Tet-on 293 cell line

and the mutation frequency of SupF reporter gene was detected in the presence and absence of DOX.Results:The pTCR-C1 plasmid was identified with the methods of restriction digestion and DNA sequencing.The mutation frequency of SupF reporter gene in the presence of DOX was higher than in the absence of DOX.Conclusion:The TCR pathway takes part in the UVC-induced SupF gene mutation in Tet-on 293 cell line.