Knock-out

Knock-out (KO) models are used to disrupt or inactivate a target gene. Depending on your project and objectives, different KO can be established:

 

• Constitutive KO: gene permanent inactivation in all cells throughout development
• Conditional KO: gene inactivation in a time- or tissue-specific manner. The conditional KO(cKO) is achieved through the use of tissue-specific Cre or inducible CreER^T2 mice. See our dedicated page for more information regarding Cre and CreER^T2 lines.

 

Advantages

• Gene inactivation is the simplest approach to elucidate the elementary function of a gene.
• Conditional KO can bypass lethal phenotype associated with gene inactivation at early developmental steps.
• Analysis of gene inactivation effects on adult animal (pathologies that normally occurs on adulthood).
• As 65% of protein coding genes are likely pleiotropic (single gene controlling or influencing multiple (and possibly unrelated) phenotypic traits, de Angelis et al., 2015), conditional knock-out simplify phenotyping analyses by focusing on a specific cell type.

Drawbacks

• Gene inactivation or disruption can be compensated by other members of a multigene family ; several KO should be realized in some cases to obtain phenotype effects (ex: Hox genes).
• Gene KO may fail to produce observable phenotypes in mice or rat or may produce different characteristics from those observed in humans in which the same gene has been inactivated.

Note: genetic background limits generalizability of genotype - phenotype relationships (Sittig et al., 2016); other inbred or outbred backgrounds may better recapitulate Human phenotypes.

Recommended technics

Depending on your project and objectives, KO animals can be obtained through

• Homologous recombination in ES cells for conditional KO models.
• Genome editing nucleases for KO models.

For KO models generation request please contact us

PHENOMIN expertise

• PHENOMIN participates to the EUCOMMtools, IKMC and IMPC consortia for the production of cKO ES cells and mice and for the creation and characterization of tissue-specific Cre and CreER^T2 models.
• Personalized genome engineering service to fit our customer needs.
• Implication in international consortia (near 20 different consortia) to benefit from the last technics and scientific expertise.
• Continuous R&D activity to improve our technics and success rate and propose our customers the best approach for their projects.
• PHENOMIN designed the European CREATE recommendations for using the cre/loxP system.