PUBLICATION

A robust knock-in approach using a minimal promoter and a minicircle

Authors
Keating, M., Hagle, R., Osorio-Mendez, D., Rodriguez-Parks, A., Almutawa, S.I., Kang, J.
ID
ZDB-PUB-231017-56
Date
2023
Source
Developmental Biology   505: 24-33 (Journal)
Registered Authors
Kang, Junsu
Keywords
CRISPR/Cas9, Knock-in, Minicircle, Zebrafish, fgf20b, scn8ab
MeSH Terms
  • Animals
  • Animals, Genetically Modified
  • CRISPR-Cas Systems*/genetics
  • Gene Editing
  • Gene Knock-In Techniques
  • Zebrafish*/genetics
PubMed
37839785 Full text @ Dev. Biol.
Abstract
Knock-in reporter (KI) animals are essential tools in biomedical research to study gene expression impacting diverse biological events. While CRISPR/Cas9-mediated genome editing allows for the successful generation of KI animals, several factors should be considered, such as low expression of the target gene, prevention of bacterial DNA integration, and in-frame editing. To circumvent these challenges, we developed a new strategy that utilizes minicircle technology and introduces a minimal promoter. We demonstrated that minicircles serve as an efficient donor DNA in zebrafish, significantly enhancing KI events compared to plasmids containing bacterial backbones. In an attempt to generate a KI reporter for scn8ab, we precisely integrated a fluorescence gene at the start codon. However, the seamlessly integrated reporter was unable to direct expression that recapitulates endogenous scn8ab expression. To overcome this obstacle, we introduced the hsp70 minimal promoter to provide an ectopic transcription initiation site and succeeded in establishing stable KI transgenic reporters for scn8ab. This strategy also created a fgf20b KI reporter line with a high success rate. Furthermore, our data revealed that an unexpectedly edited genome can inappropriately influence the integrated reporter gene expression, highlighting the importance of selecting a proper KI line. Overall, our approach utilizing a minicircle and an ectopic promoter establishes a robust and efficient strategy for KI generation, expanding our capacity to create KI animals.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping