Horizontal gene transfer
In horizontal gene transfer, genetic material is transferred between two organisms by methods other than reproduction.
Horizontal gene transfer is the main method of creating genetic variation in bacteria.
There are three methods of gene transfer in bacteria:
- Transformation: uptake of DNA from the environment.
- Transduction: transfer of genes by a bacteriophage.
- Conjugation: exchange of DNA directly between two bacterial cells that are not reproducing.
Horizontal gene transfer is rare in eukaryotes but very common in prokaryotes such as bacteria.
E. coli has acquired 18% of its current genome through horizontal gene transfer.