Development of an Effective 6-Methylpurine Counterselection Marker for Genetic Manipulation in Thermococcus barophilus
AbstractA gene disruption system for Thermococcus barophilus was developed using simvastatin (HMG-CoA reductase encoding gene) for positive selection and 5-Fluoroorotic acid (5-FOA), a pyrF gene for negative selection. Multiple gene mutants were constructed with this system, which offers the possibility of complementation in trans, but produces many false positives (<80%). To significantly reduce the rate of false positives, we used another counterselective marker, 6-methylpurine (6-MP), a toxic analog of adenine developed in Thermococcus kodakarensis, consistently correlated with the TK0664 gene (encoding a hypoxanthine-guanine phosphoribosyl-transferase). We thus replaced pyrF by TK0664 on our suicide vector and tested T. barophilus strain sensitivity to 6-MP before and after transformation. Wild-Type (WT) T. barophilus is less sensitive to 6-MP than WT T. kodakarensis, and an increase of cell resistance was achieved after deletion of the T. barophilus TERMP_00517 gene homologous to T. kodakarensis TK0664. Results confirmed the natural resistance of T. barophilus to 6-MP and show that TK0664 can confer sensitivity. This new counterselection system vastly improves genetic manipulations in T. barophilus MP, with a strong decrease in false positives to <15%. Using this genetic tool, we have started to investigate the functions of several genes involved in genomic maintenance (e.g., polB and rnhB). View Full-Text
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Birien, T.; Thiel, A.; Henneke, G.; Flament, D.; Moalic, Y.; Jebbar, M. Development of an Effective 6-Methylpurine Counterselection Marker for Genetic Manipulation in Thermococcus barophilus. Genes 2018, 9, 77.
Birien T, Thiel A, Henneke G, Flament D, Moalic Y, Jebbar M. Development of an Effective 6-Methylpurine Counterselection Marker for Genetic Manipulation in Thermococcus barophilus. Genes. 2018; 9(2):77.Chicago/Turabian Style
Birien, Tiphaine; Thiel, Axel; Henneke, Ghislaine; Flament, Didier; Moalic, Yann; Jebbar, Mohamed. 2018. "Development of an Effective 6-Methylpurine Counterselection Marker for Genetic Manipulation in Thermococcus barophilus." Genes 9, no. 2: 77.
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