Efficient Generation of Large-Fragment Knock-In Mouse Models Using 2-Cell (2C)-Homologous Recombination (HR)-CRISPR

© 2020 John Wiley & Sons, Inc..

Generating large-fragment knock-ins, such as reporters, conditional alleles, or humanized alleles, directly in mouse embryos is still a challenging feat. We have developed 2C-HR-CRISPR, a technology that allows highly efficient (10-50%) and rapid (generating founders in 2 months) targeting of large DNA fragments. Key to this strategy is the delivery of CRISPR reagents into 2-cell-stage mouse embryos, taking advantage of the high homologous recombination activity during the long G2 cell cycle phase at this stage. Furthermore, by exploiting a Cas9-monomeric streptavidin (Cas-mSA) and biotinylated PCR template (BioPCR) system to localize the repair template to specific double strand breaks, the efficiency can be further improved to up to 95%. Here we provide a procedure to generate large-fragment knock-in mouse models using 2C-HR-CRISPR. We first describe the principles for designing single guide RNAs and repair templates but refer to published manuscripts and protocols for molecular cloning methods or commercial sources for these reagents. We then describe two unique aspects of 2C-HR-CRISPR that are critical for success: (1) production of the CRISPR reagents for 2C-HR-CRISPR, particularly for applying the Cas9-mSA/BioPCR method, and (2) microinjection of mouse embryos at the 2-cell stage. © 2020 by John Wiley & Sons, Inc. Basic Protocol 1: Single guide RNA and repair template design Basic Protocol 2: Preparing reagents for 2C-HR-CRISPR Basic Protocol 3: Microinjecting 2-cell-stage mouse embryos.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:10

Enthalten in:

Current protocols in mouse biology - 10(2020), 1 vom: 21. März, Seite e67

Sprache:

Englisch

Beteiligte Personen:

Gu, Bin [VerfasserIn]
Posfai, Eszter [VerfasserIn]
Gertsenstein, Marina [VerfasserIn]
Rossant, Janet [VerfasserIn]

Links:

Volltext

Themen:

2-cell embryos
CRISPR-Cas9
Conditional allele
Genome editing
Homologous recombination
Humanization
Journal Article
Large fragment knock-in
Microinjection
Reporter

Anmerkungen:

Date Completed 29.09.2020

Date Revised 29.09.2020

published: Print

Citation Status MEDLINE

doi:

10.1002/cpmo.67

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM305123653