PUBLICATION

CRISPR/Cas9-mediated precise genome modification by a long ssDNA template in zebrafish

Authors
Bai, H., Liu, L., An, K., Lu, X., Harrison, M., Zhao, Y., Yan, R., Lu, Z., Li, S., Lin, S., Liang, F., Qin, W.
ID
ZDB-PUB-200123-3
Date
2020
Source
BMC Genomics   21: 67 (Journal)
Registered Authors
Harrison, Michael, Lin, Shuo, Qing, Wei
Keywords
CRISPR/Cas9, Disease modeling, Genome editing, Homology-directed repair, Long single-stranded DNA, Next-generation sequencing, Zebrafish
MeSH Terms
  • Amino Acid Substitution
  • Animals
  • CRISPR-Cas Systems*
  • DNA, Single-Stranded*
  • Gene Editing*
  • Gene Knock-In Techniques
  • Gene Targeting
  • Genetic Predisposition to Disease
  • Humans
  • Loss of Function Mutation
  • RNA, Guide, Kinetoplastida
  • Sequence Analysis, DNA
  • Zebrafish/genetics*
PubMed
31964350 Full text @ BMC Genomics
Abstract
Gene targeting by homology-directed repair (HDR) can precisely edit the genome and is a versatile tool for biomedical research. However, the efficiency of HDR-based modification is still low in many model organisms including zebrafish. Recently, long single-stranded DNA (lssDNA) molecules have been developed as efficient alternative donor templates to mediate HDR for the generation of conditional mouse alleles. Here we report a method, zLOST (zebrafish long single-stranded DNA template), which utilises HDR with a long single-stranded DNA template to produce more efficient and precise mutations in zebrafish.
The efficiency of knock-ins was assessed by phenotypic rescue at the tyrosinase (tyr) locus and confirmed by sequencing. zLOST was found to be a successful optimised rescue strategy: using zLOST containing a tyr repair site, we restored pigmentation in at least one melanocyte in close to 98% of albino tyr25del/25del embryos, although more than half of the larvae had only a small number of pigmented cells. Sequence analysis showed that there was precise HDR dependent repair of the tyr locus in these rescued pigmented embryos. Furthermore, quantification of zLOST knock-in efficiency at the rps14, nop56 and th loci by next generation sequencing demonstrated that zLOST showed a clear improvement. We utilised the HDR efficiency of zLOST to precisely model specific human disease mutations in zebrafish with ease. Finally, we determined that this method can achieve a germline transmission rate of up to 31.8%.
In summary, these results show that zLOST is a useful method of zebrafish genome editing, particularly for generating desired mutations by targeted DNA knock-in through HDR.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping