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 util...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-C 1 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.展开更多
The availability of a large number of sequenced bacterial genomes facilitates in-depth studies about why genes(operons)in a bacterial genome are globally organized the way they are.We have previously discovered that(t...The availability of a large number of sequenced bacterial genomes facilitates in-depth studies about why genes(operons)in a bacterial genome are globally organized the way they are.We have previously discovered that(the relative)transcription-activation frequencies among different biological pathways encoded in a genome have a dominating role in the global arrangement of operons.One complicating factor in such a study is that some operons may be involved in multiple pathways with different activation frequencies.A quantitative model has been developed that captures this information,which tends to be minimized by the current global arrangement of operons in a bacterial(and archaeal)genome compared to possible alternative arrangements.A study is carried out here using this model on a collection of 52 closely related Escherichia coli genomes,which revealed interesting new insights about how bacterial genomes evolve to optimally adapt to their environments through adjusting the(relative)genomic locations of the encoding operons of biological pathways once their utilization and hence transcription activation frequencies change,to maintain the above energy-efficiency property.More specifically we observed that it is the frequencies of the transcription activation of pathways relative to those of the other encoded pathways in an organism as well as the variation in the activation frequencies of a specific pathway across the related genomes that play a key role in the observed commonalities and differences in the genomic organizations of genes(and operons)encoding specific pathways across different genomes.展开更多
基金the National Natural Science Foundation of China(30471958)the Natural Science Foundation of Chongqing(No.2006BB5045)
文摘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-C 1 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.
基金supported in part by National Science Foundation (#NSF DEB-0830024 and NSF MCB-0958172)the US Department of Energy’s BioEnergy Science Center grant through the Office of Biological and Environmental Research+1 种基金The BioEnergy Science Center is a US Department of Energy Bioenergy Research Center supported by the Office of Biological and Environmental Research in the DOE Office of ScienceFunding for open access charge: US Department of Energy’s BioEnergy Science Center
文摘The availability of a large number of sequenced bacterial genomes facilitates in-depth studies about why genes(operons)in a bacterial genome are globally organized the way they are.We have previously discovered that(the relative)transcription-activation frequencies among different biological pathways encoded in a genome have a dominating role in the global arrangement of operons.One complicating factor in such a study is that some operons may be involved in multiple pathways with different activation frequencies.A quantitative model has been developed that captures this information,which tends to be minimized by the current global arrangement of operons in a bacterial(and archaeal)genome compared to possible alternative arrangements.A study is carried out here using this model on a collection of 52 closely related Escherichia coli genomes,which revealed interesting new insights about how bacterial genomes evolve to optimally adapt to their environments through adjusting the(relative)genomic locations of the encoding operons of biological pathways once their utilization and hence transcription activation frequencies change,to maintain the above energy-efficiency property.More specifically we observed that it is the frequencies of the transcription activation of pathways relative to those of the other encoded pathways in an organism as well as the variation in the activation frequencies of a specific pathway across the related genomes that play a key role in the observed commonalities and differences in the genomic organizations of genes(and operons)encoding specific pathways across different genomes.
