Investigating in situ natural genetic transformation of Acinetobacter sp. BD413 in biofilms with confocal laser scanning microscopy.

Abstract

Natural genetic transformation is defined as the active uptake of free DNA, released in the environment through lysis or excretion, by bacterial strains that are naturally competent for transformation. It has been observed in a wide range of organisms (1). Of the three horizontal gene transfer processes — transformation, conjugation, and transduction — natural genetic transformation has the least requirements (1). For instance, there is no need for the donor cell to be alive or physically intact. Spatial and temporal separation between competent cells and the source of DNA in the environment can be overcome since nucleic acids are often found adsorbed to minerals (2), humic acids (3) or other components (1), where they are shielded from DNase attack. Consequently, DNA that survives can potentially be used for natural genetic transformation of recipient cells if those cells possess the ability to change into a state conferring competence for transformation (1). The process of transformation has been divided into the following steps (1,4,5): (i) release of DNA from cells; (ii) dispersal and (iii) persistence of the DNA in the environment; (iv) the development of competence for DNA uptake by cells in the natural habitat; (v) the interaction of cells with DNA and the uptake of DNA; and (vi) the expression of an acquired trait following DNA uptake (1).KeywordsConfocal Laser Scanning MicroscopyHorizontal Gene TransferTransformation FrequencyPeptide Nucleic AcidNucleic Acid StainThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.