Production of knockout mice by DNA microinjection of various CRISPR/Cas9 vectors into freeze-thawed fertilized oocytes

BMC Biotechnology

Methodology Article

Yoshiko Nakagawa¹  Masaki Ohmuraya¹  Naomi Nakagata¹  Takuya Sakamoto²  Takashi Yamamoto²  Tetsushi Sakuma² 

[1] Center for Animal Resources and Development, Kumamoto University, 860-0811, Kumamoto, Japan;Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, 739-8526, Hiroshima, Japan;

关键词: Knockout mouse;    Pronuclear microinjection;    In vitro;    Freeze-thawing;    CRISPR/Cas9;    Double-nicking;    FokI-dCas9;   

DOI  :  10.1186/s12896-015-0144-x

 received in 2015-01-09, accepted in 2015-04-17,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundClustered regulatory interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated genome editing permits the rapid production of genetically engineered mice. To make the most of this innovative technology, a streamlined procedure is needed for the robust construction of CRISPR/Cas9 vectors, the efficient preparation of mouse oocytes, and refined genotyping strategies. Although we previously demonstrated the applicability of oocyte cryopreservation technologies and various genotyping methods in the production of transcription activator-like effector nuclease-mediated genome editing in mice, it has not yet been clarified whether these techniques can be applied to the CRISPR/Cas9-mediated generation of knockout mice. In this study, we investigated easy, efficient, and robust methods of creating knockout mice using several CRISPR/Cas9 systems.ResultsWe constructed three types of CRISPR/Cas9 vectors expressing: 1) single guide RNA (gRNA) and Cas9 nuclease, 2) two gRNAs and Cas9 nickase, and 3) two gRNAs and FokI-dCas9, targeting the same genomic locus. These vectors were directly microinjected into the pronucleus of freeze-thawed fertilized oocytes, and surviving oocytes were transferred to pseudopregnant ICR mice. Cas9 nuclease resulted in the highest mutation rates with the lowest birth rates, while Cas9 nickase resulted in the highest birth rates with the lowest mutation rates. FokI-dCas9 presented well-balanced mutation and birth rates. Furthermore, we constructed a single all-in-one FokI-dCas9 vector targeting two different genomic loci, and validated its efficacy by blastocyst analysis, resulting in highly efficient simultaneous targeted mutagenesis.ConclusionsOur report offers several choices of researcher-friendly consolidated procedures for making CRISPR/Cas9-mediated knockout mice, with sophisticated construction systems for various types of CRISPR vectors, convenient preparation of in vitro fertilized or mated freeze-thawed oocytes, and an efficient method of mutant screening.

【 授权许可】

Unknown   
© Nakagawa et al.; licensee BioMed Central. 2015. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.