What is Gene knockout?
A '''gene knockout''' is a [[genetics|genetic]] technique in which one of an [[organism]]'s [[gene]]s is switched off or replaced by one which does not work. The organisms, such as [[Knockout mouse|knockout mice]], are used to learn about a gene that has been [[DNA sequencing|sequenced]], but whose [[Function (biology)|function]] is unknown or incompletely known. Researchers draw [[infer]]ences from the difference between the knockout organism and normal individuals. Knockout is often abbreviated as '''KO'''. '''Gene knock-in''' is the opposite term. There a gene is switched on, or a working gene inserted. ==Method== Knockout is accomplished through a [[genetic engineering|combination of techniques]]. It starts in the test tube with a [[plasmid]], or other [[DNA construct]], and proceeding to [[cell culture]]. Individual [[cells]] are genetically [[Transformation (genetics)|transformed]] with the DNA construct. Often the goal is to create an animal that has the altered gene. If so, [[embryonic stem cell]]s are genetically transformed and inserted into early [[embryo]]s. Resulting animals with the genetic change in their [[germline]] cells can then often pass the gene knockout to future generations. [[Category:Genetic engineering]] [[Category:Molecular biology]]