What is Knockout mouse?
A '''knockout mouse''' is a [[genetic engineering|genetically engineered]] [[house mouse|mouse]] in which one or more [[gene]]s have been turned off by a [[gene knockout]]. Knockout mice are important animal [[Model organism|model]]s for studying the role of genes which have been [[DNA sequencing|sequenced]] but whose [[Function (biology)|function]]s are not yet known. By causing a specific gene to be inactive in the mouse, and observing any differences from normal behaviour or condition, researchers can [[infer]] its probable function. Mice are currently the most closely related [[model organism|laboratory animal species]] to [[human]]s for which the knockout technique can easily be applied. They are widely used in knockout experiments, especially those genetic questions which relate to human [[physiology]]. Gene knockout in [[brown rat|rats]] is much harder and has only been possible since 2003.<ref>[http://www.nature.com/news/1998/030512/full/news030512-17.html naturenews, 19 May 2003]</ref><ref>{{Cite web |url=http://molpharm.wisc.edu/Faculty/fac_pages/gould/Pub12754522.pdf |title=Y Zan et al., Production of knockout rats using ENU mutagenesis and a yeast-based screening assay, Nat. Biotechnol. (2003). |access-date=2011-02-24 |archive-date=2010-06-11 |archive-url=https://web.archive.org/web/20100611201320/http://molpharm.wisc.edu/Faculty/fac_pages/gould/Pub12754522.pdf |url-status=dead }}</ref> The first knockout mouse was created by [[Mario Capecchi|Mario R. Capecchi]], [[Martin Evans]] and [[Oliver Smithies]] in 1989, for which they were awarded the [[Nobel Prize in Physiology or Medicine]] for 2007. A detailed explanation of how knockout (KO) mice are produced is at the website of the [[Nobel Prize in Physiology or Medicine]] 2007.<ref>Nobel Prize detailed explanation of the work [http://www.nobelprize.org/nobel_prizes/medicine/laureates/2007/advanced.html]</ref> Aspects of the technology for generating knockout mice, and the mice themselves have been [[patent]]ed in many countries by private com