Pros And Cons Of Conditional Knockouts
Conditional Knockout Models
Knockout models can be roughly divided into conventional knockout models and conditional knockout models. Although conventional knockouts offer a way to study gene function at a systematic level, many researchers choose a conditional knockout approach instead due to their lethality risk and/or their limitations of analyzing a gene’s role in the organogenesis of a particular tissue. With Cre/loxP technology, which is frequently used to create conditional knockout models, however, these problems can be overcome or circumvented. Below we discuss options for conventional knockout strategies:
Cre/LoxP System-based Targeting
Conditional knockouts can be achieved via a chromosome site-specific recombinant enzyme system,
such as Cre/LoxP, FLP/Frt, and Dre/Rox, among which Cre-LoxP system is the most frequently employed. Herein, the loxP sites, two 34 bp nucleotide sequences, are inserted around an essential exon in a gene and the region between these two loxP sites are excised by the Cre recombinase, which is derived from the P1 bacteriophage. As a result, mice that are phenotypically wildtype but containing the floxed allele in all tissues can be obtained. When mating to different Cre mice, tissue-specific or inducible knockout mice are generated. Apart from the Cre/loxP technology, the Flp/Frt system and Dre/Rox are also two means of creating traditional knockouts, less frequently used but still helpful. In brief, conditional models enable the study of gene inactivation in a specific cell type, tissue of interest, or at a defined developmental stage. Please click the links below for more detailed information of each type.
Tissue-specific Knockout Mice
A conditional type which inactivates gene expression in a specific target tissue. This type of model is often used to study the function of lethal genes, identify target gene of drugs, and evaluate drugs in preclinical studies.
Inducible Knockout Mice
This is a conditional kncokout model in which the expression of the target gene can be specifically inactivated in a time-controlled manner. Thus, the model expresses wildtype proteins and mutant proteins before and after induction, respectively. Especially, this model can be used in studies of diseases that are related to development or age.
CRISPR/Cas9 Based Targeting Strategy
Two components of sg RNA (crRNA and tracrRNA) are designed and synthesized. The guide RNAs targeting specific loci in the genome will guide Cas9 enzyme to the locus and cause DNA double strain break (DSB). Homologous recombination (HR) will enable the donor fragment which contains loxP (or frt) sites to integrate into the breaking locus.
In the meanwhile, Creative Biolabs offers other types of knockout models that you may be interested in:
Conventional Knockout Models
KO First (Conditional-Ready) Models
With the support of cutting-edge technologies and specialists in this field, Creative Biolabs is proud to offer the most reliable genome engineering model services at most favorable prices currently on the market. Contact or inquire us to discuss the ideal custom mouse model to boost the impact of your next project and beyond.
Knockout models can be roughly divided into conventional knockout models and conditional knockout models. Although conventional knockouts offer a way to study gene function at a systematic level, many researchers choose a conditional knockout approach instead due to their lethality risk and/or their limitations of analyzing a gene’s role in the organogenesis of a particular tissue. With Cre/loxP technology, which is frequently used to create conditional knockout models, however, these problems can be overcome or circumvented. Below we discuss options for conventional knockout strategies:
Cre/LoxP System-based Targeting
Conditional knockouts can be achieved via a chromosome site-specific recombinant enzyme system,
such as Cre/LoxP, FLP/Frt, and Dre/Rox, among which Cre-LoxP system is the most frequently employed. Herein, the loxP sites, two 34 bp nucleotide sequences, are inserted around an essential exon in a gene and the region between these two loxP sites are excised by the Cre recombinase, which is derived from the P1 bacteriophage. As a result, mice that are phenotypically wildtype but containing the floxed allele in all tissues can be obtained. When mating to different Cre mice, tissue-specific or inducible knockout mice are generated. Apart from the Cre/loxP technology, the Flp/Frt system and Dre/Rox are also two means of creating traditional knockouts, less frequently used but still helpful. In brief, conditional models enable the study of gene inactivation in a specific cell type, tissue of interest, or at a defined developmental stage. Please click the links below for more detailed information of each type.
Tissue-specific Knockout Mice
A conditional type which inactivates gene expression in a specific target tissue. This type of model is often used to study the function of lethal genes, identify target gene of drugs, and evaluate drugs in preclinical studies.
Inducible Knockout Mice
This is a conditional kncokout model in which the expression of the target gene can be specifically inactivated in a time-controlled manner. Thus, the model expresses wildtype proteins and mutant proteins before and after induction, respectively. Especially, this model can be used in studies of diseases that are related to development or age.
CRISPR/Cas9 Based Targeting Strategy
Two components of sg RNA (crRNA and tracrRNA) are designed and synthesized. The guide RNAs targeting specific loci in the genome will guide Cas9 enzyme to the locus and cause DNA double strain break (DSB). Homologous recombination (HR) will enable the donor fragment which contains loxP (or frt) sites to integrate into the breaking locus.
In the meanwhile, Creative Biolabs offers other types of knockout models that you may be interested in:
Conventional Knockout Models
KO First (Conditional-Ready) Models
With the support of cutting-edge technologies and specialists in this field, Creative Biolabs is proud to offer the most reliable genome engineering model services at most favorable prices currently on the market. Contact or inquire us to discuss the ideal custom mouse model to boost the impact of your next project and beyond.