Chromosomal transfers in mycoplasmas: when minimal genomes go mobile.
Bottom Line: One main mechanism involves conjugation, a process that allows the simultaneous transfer of significant amounts of DNA upon cell-to-cell contact.In these organisms, HGT was long thought to be marginal.The transfer involved DNA blocks containing up to 80 genes that were incorporated into the host chromosome by homologous recombination.
Affiliation: University of Melbourne, Department of Veterinary Science, Werribee, Victoria, Australia.Show MeSH
Related in: MedlinePlus
Mentions: To better define which portions of the M. agalactiae chromosome can be transferred, 10 individual PG2G clones having the selective marker inserted at different loci (Table 1) were chosen from a well-characterized PG2G minilibrary (23, 25). These potential donors were then individually mated in parallel experiments with one single 5632T clone, 5632T-H3, as the recipient strain (Fig. 2). Again, clone 5632T-H3 had the Tet selective marker inserted outside any known mobile element (nt 529737). Transconjugants were obtained in all mating attempts, indicating that the 10 individual PG2G clones are able to conjugate with 5632T-H3 regardless of the position of the selective marker (Table 1). From each mating, 20 individual transconjugants were then randomly picked, grown, and typed by PCR as described above. Results indicated that the 200 transconjugants all possessed the two selective markers and displayed the 5632 genomic backbone (see Materials and Methods; also, see Fig. S1 in the supplemental material), confirming this strain as the recipient.
Affiliation: University of Melbourne, Department of Veterinary Science, Werribee, Victoria, Australia.