Horizontal Gene Transfer

Horizontal gene transfer is unique to prokaryotes and describes gene transfer between two mature cells which is different than vertical gene transfer (mother to daughter). The three major mechanisms of gene transfer are transformation, transduction, and conjugation (please see Ch 10). Transformation is gene variation by the direct uptake and insertion of a foreign genetic material outside the cell. Transduction is the process in which foreign DNA is inserted into a cell by a viral vector. Conjugation is the transfer of genetic material via a pilus by direct attachment of the donor cell to the recipient cell. The genetic material is then incorporated into the recipient genome. Such gene transfer processes can be an opportunity for genetic diversity for usual asexual prokaryotes.

1) Madigan, M. T., & Brock, T. D. (2012). Brock biology of microorganisms. Boston: Benjamin Cummings.

Molecular Microbiology – Figure 1.

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