Efficient generation of knock-in transgenic zebrafish carrying reporter/driver genes by CRISPR/Cas9-mediated genome engineering

Y Kimura, Y Hisano, A Kawahara, S Higashijima - Scientific reports, 2014 - nature.com
Y Kimura, Y Hisano, A Kawahara, S Higashijima
Scientific reports, 2014nature.com
The type II bacterial CRISPR/Cas9 system is rapidly becoming popular for genome-
engineering due to its simplicity, flexibility and high efficiency. Recently, targeted knock-in of
a long DNA fragment via homology-independent DNA repair has been achieved in zebrafish
using CRISPR/Cas9 system. This raised the possibility that knock-in transgenic zebrafish
could be efficiently generated using CRISPR/Cas9. However, how widely this method can
be applied for the targeting integration of foreign genes into endogenous genomic loci is …
Abstract
The type II bacterial CRISPR/Cas9 system is rapidly becoming popular for genome-engineering due to its simplicity, flexibility and high efficiency. Recently, targeted knock-in of a long DNA fragment via homology-independent DNA repair has been achieved in zebrafish using CRISPR/Cas9 system. This raised the possibility that knock-in transgenic zebrafish could be efficiently generated using CRISPR/Cas9. However, how widely this method can be applied for the targeting integration of foreign genes into endogenous genomic loci is unclear. Here, we report efficient generation of knock-in transgenic zebrafish that have cell-type specific Gal4 or reporter gene expression. A donor plasmid containing a heat-shock promoter was co-injected with a short guide RNA (sgRNA) targeted for genome digestion, a sgRNA targeted for donor plasmid digestion and Cas9 mRNA. We have succeeded in establishing stable knock-in transgenic fish with several different constructs for 4 genetic loci at a frequency being exceeding 25%. Due to its simplicity, design flexibility and high efficiency, we propose that CRISPR/Cas9-mediated knock-in will become a standard method for the generation transgenic zebrafish.
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