Molecular analysis of RecA-independent genetic recombination in Pseudomonas aeruginosa

BORGOGNO MARÍA V.; MONTI MARIELA R; MORO CAMILA; ARGARAÑA CARLOS E.

Jornada; XXV Jornadas Científicas de la Sociedad de Biología de Córdoba; 2017

Genetic recombination is involved in severalphysiological pathways that are essential for the genomic  maintenance and diversification. At present multiplemechanisms are known to mediate this process, both dependent and independent ofthe recombinase RecA. In order to study the recombination processin P. aeruginosa and E. coli, we used a plasmidic systemwhich allows us to determine both homologous and homeologous recombination.Moreover, the recombination of this system creates a functional copy of theLacZ gene and thus, the recombinant clones can be detected by their βgalactosidase activity. We found that in E. coli, the majority of the recombination events occur in a RecAdependent fashion and all the clones showed β galactosidase activity, as it wasexpected. In P. aeruginosa however,an important fraction of recombination events occurred independently of RecA. Furthermore, many clones showed no βgalactosidase activity, and contained numerous small mutations in the recombinedcoding region of LacZ. This resultssuggest to the existence of a recombinationmechanism independentof RecA, and at difference of E. coli, significantly mutagenic in P. aeruginosa.