Chromatin accessibility is associated with CRISPR-Cas9 efficiency in the zebrafish (Danio rerio)

PLoS One. 2018 Apr 23;13(4):e0196238. doi: 10.1371/journal.pone.0196238. eCollection 2018.


CRISPR-Cas9 technology is routinely applied for targeted mutagenesis in model organisms and cell lines. Recent studies indicate that the prokaryotic CRISPR-Cas9 system is affected by eukaryotic chromatin structures. Here, we show that the likelihood of successful mutagenesis correlates with transcript levels during early development in zebrafish (Danio rerio) embryos. In an experimental setting, we found that guide RNAs differ in their onset of mutagenesis activity in vivo. Furthermore, some guide RNAs with high in vitro activity possessed poor mutagenesis activity in vivo, suggesting the presence of factors that limit the mutagenesis in vivo. Using open access datasets generated from early developmental stages of the zebrafish, and guide RNAs selected from the CRISPRz database, we provide further evidence for an association between gene expression during early development and the success of CRISPR-Cas9 mutagenesis in zebrafish embryos. In order to further inspect the effect of chromatin on CRISPR-Cas9 mutagenesis, we analysed the relationship of selected chromatin features on CRISPR-Cas9 mutagenesis efficiency using publicly available data from zebrafish embryos. We found a correlation between chromatin openness and the efficiency of CRISPR-Cas9 mutagenesis. These results indicate that CRISPR-Cas9 mutagenesis is influenced by chromatin accessibility in zebrafish embryos.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CRISPR-Cas Systems
  • Chromatin / chemistry*
  • Chromatin / genetics
  • Databases, Genetic
  • Embryonic Development
  • Gene Expression
  • Gene Expression Regulation, Developmental
  • RNA, Guide / genetics*
  • Transcriptional Activation
  • Zebrafish / embryology*
  • Zebrafish / genetics
  • Zebrafish Proteins / genetics*


  • Chromatin
  • RNA, Guide
  • Zebrafish Proteins

Grant support

This study was supported with the following grants: Tampere Tuberculosis Foundation ( (MU;MR); Finnish Concordia Fund ( (MU); Sigrid Juselius Foundation ( (MR); University of Tampere Doctoral School ( (MU); Finnish Cultural Foundation – Maili Autio Fund ( (HB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.