F-plasmid

This MedLibrary.org supplementary page on F-plasmid is provided directly from the open source Wikipedia as a service to our readers. Please see the note below on authorship of this content, as well as the Wikipedia usage guidelines. To search for other content from our encyclopedia supplement, please use the form below:

The Fertility factor (also known as F factor or sex factor) is a bacterial DNA sequence that allows a bacterium to produce a sex pilus necessary for conjugation. It contains 20 tra (for "transfer") genes and a number of other genetic sequences responsible for incompatibility, replication, and other functions. The F factor is an episome and can exist as an independent plasmid or integrate into the bacterial cell's genome. There are several names for the possible states:

  • Hfr-strain after integration into the host chromosomal DNA, these plasmids possess portions, or entire, F factor and portions of the bacterial genome.
  • F+ bacteria possess F factor as a plasmid independent of the bacterial genome. The F plasmid contains only F factor DNA and no DNA from the bacterial genome.
  • F' (F-prime) bacteria possess an F plasmid that also includes some DNA taken from the bacterial genome.
  • F- bacteria do not contain F factor.

When an F+ cell conjugates with an F cell, the result is two F+ cells, both capable of transmitting the plasmid further by conjugation. Unlike other plasmids, F factor is constitutive for transfer proteins due to the gene Tra J. This means that an F+ bacteria can always act as a donor cell. In the case of Hfr, the result are two Hfr cells. When F-prime plasmids are transferred to a recipient bacterial cell, they carry pieces of the donor's DNA that can become important in recombination. Bioengineers have created F plasmids that can contain inserted foreign DNA; this is called a fosmid.

This microbiology-related article is a stub. You can help Wikipedia by expanding it.

Wikipedia content modification information:

  • This page was last modified on 6 November 2008, at 22:29.

Wikipedia Authorship and Review

Wikipedia content provided here is not reviewed directly by MedLibrary.org. Wikipedia content is authored by an open community of volunteers and is not produced by or in any way affiliated with MedLibrary.org.

Wikipedia Usage Guidelines

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on "F-plasmid".

The URL for this specific entry is:

All Wikipedia text is available under the terms of the GNU Free Documentation License. (See Copyrights for details). Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.