Wednesday, May 23, 2012

Transposome-based mutagenesis to develop a Planctomycetes model organism

Microbial geneticists continue to use the EZ-Tn5 in vivo transposomics tools for establishing genetic systems in novel bacteria. Jogler et al. report on the Planctomycetes phylum of bacteria which is a major component of the global nitrogen and carbon cycles. These bacteria perform reactions such as the anaerobic oxidation of ammonium ions. Many Planctomycetes strains are difficult to cultivate, so the researchers developed a model system using the P. limnophilus strain due to its cultivability, sensitivity to kanamycin, rapid growth, and availability of the genome sequence.

The authors used the EZ-Tn5 <R6Kgamma/KAN-2> Transposome in a standard in vivo transposition reaction to generate mutants that were detected by i) Kan resistance and ii) modified arbitrary PCR. The mutants were screened using a second arbitrary PCR step. Analysis showed that nine mutations were generated that were pinpointed to specific regions on the chromosome. The authors comment that there appeared to be only insignificant regional bias in the insertion sites. The authors further noted that the intracellular membrane and the condensed nucleoid did not appear to have any negative effect on the transposition; thus, the likelihood of gene transfer and mutagenesis in Planctobacillus spp. appears to be quite good. These results will enable future in-depth genetic analysis of Planctomycetes.

ResearchBlogging.orgJogler, C. et al. (2011). Characterization of Planctomyces limnophilus and Development of Genetic Tools for Its Manipulation Establish It as a Model Species for the Phylum Planctomycetes Applied and Environmental Microbiology, 77 (16), 5826-5829 DOI: 10.1128/AEM.05132-11

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