Depending on the model design, knockout models may be used to validate therapeutic compounds during drug discovery, explore cellular processes, gain insights into disease pathogenesis and prevention, and more.
At Taconic, typically, we generate constitutive knockout mouse or rat models using CRISPR/Cas9 technology in embryos and conditional knockout mouse models using homologous recombination (HR) in embryonic stem cells (ESCs). CRISPR/Cas9 methodology is well suited for generating precise deletions within the genome. Currently, HR in ESCs is better suited for generating conditional knockout alleles because it allows for extensive molecular characterization early on in the project, guaranteeing that both loxP sites are correctly integrated on the same chromosome.
Conditional knockout alleles are quite versatile — depending on the expression pattern of the Cre line used for crossbreeding, either a constitutive knockout, a tissue-specific conditional knockout, or an inducible conditional knockout can be obtained as outlined in the figure below.