Introductory Microbiology

Genetic Recombination

• Genetic recombination involves the physical exchange of genetic material between organisms. It involves the genetic exchange between homologous DNA sequences from two different organisms. In classical genetics, it is referred as crossing over. In prokaryotes, RecA protein is a DNA binding protein involved in the genetic recombination. The following sequence of steps involved in the genetic recombination of prokaryotes. The cell which gives DNA is donor and which receives the DNA is recipient. In prokaryotes, the genetic recombination is observed because of homologous DNA from one cell to another by three processes.

I. Transformation: Donor DNA free in the environment (naked DNA) transferred to recipient cell.
II. Transduction: Transfer of donor DNA to recipient cell by means of virus vector.
III. Conjugation: Transfer of donor DNA to recipient through cell to cell contact.