Genetic recombination in bacteria: horizon of the beginnings of sexuality in living organisms

The current paper reviews the bacterian genetic recombination. Bacteria can transfer genes from one strain to another by three different mechanisms: transformation, conjugation and transduction, these events showing the universality of sexuality in the living world. Besides genetic recombination in bacteria, recent evidences of genetic recombination in some superior animals (such as: fish, birds, mammals and humans) at the sex-chromosomes level support the ‘gene concept of sexuality’ as a general view of sexuality.