a mutant mouse that is deficient in a specific native molecule
a rodent with a gene removed
A mouse that has had both alleles of a particular gene replaced with an inactive allele, usually through homologous recombination. Knockout mice are used to determine the role of a particular gene by observing the phenotype of individuals that lack the gene completely.
A mouse in which a particular gene has been intentionally deleted through homologous recombination.
A mouse that has been engineered so that it carries an inactivated gene.
A knockout mouse is a genetically engineered mouse one or more of whose genes have been made inoperable through a gene knockout. Knockout is a route to learning about a gene that has been sequenced but has an unknown or incompletely known function. Mice are the laboratory animal species most closely related to humans in which the knockout technique can be easily performed, so they are a favorite subject for knockout experiments, especially with regard to genetic questions that relate to human physiology.
