Direct Visualization of Horizontal Gene Transfer by Transformation in Live Pneumococcal Cells Using Microfluidics.

Natural genetic transformation is a programmed mechanism of horizontal gene transfer in bacteria. It requires the development of competence, a specialized physiological state during which proteins involved in DNA uptake and chromosomal integration are produced. In , competence is transient.

Natural Genetic Transformation: A Direct Route to Easy Insertion of Chimeric Genes into the Pneumococcal Chromosome.

The ability of Streptococcus pneumoniae (the pneumococcus) to transform is particularly convenient for genome engineering. Several protocols relying on sequential positive and negative selection strategies have been described to create directed markerless modifications, including deletions, insertions, or point mutations. Transformation with DNA fragments carrying long flanking homology sequences is also used to generate mutations without selection but it requires high transformability.

Fine-tuning cellular levels of DprA ensures transformant fitness in the human pathogen Streptococcus pneumoniae.

Natural genetic transformation is a widespread mechanism of horizontal gene transfer. It involves the internalization of exogenous DNA as single strands and chromosomal integration via homologous recombination, promoting acquisition of new genetic traits. Transformation occurs during a distinct physiological state called competence.

Nascent teichoic acids insertion into the cell wall directs the localization and activity of the major pneumococcal autolysin LytA.

The bacterial cell wall is in part composed of the peptidoglycan (PG) layer that maintains the cell shape and sustains the basic cellular processes of growth and division. The cell wall of Gram-positive bacteria also carries teichoic acids (TAs). In this work, we investigated how TAs contribute to the structuration of the PG network through the modulation of PG hydrolytic enzymes in the context of the Gram-positive bacterium.

A programmed cell division delay preserves genome integrity during natural genetic transformation in Streptococcus pneumoniae.

Competence for genetic transformation is a differentiation program during which exogenous DNA is imported into the cell and integrated into the chromosome. In Streptococcus pneumoniae, competence develops transiently and synchronously in all cells during exponential phase, and is accompanied by a pause in growth. Here, we reveal that this pause is linked to the cell cycle.