Related Experiment Video

Updated: Oct 3, 2025

Indel Detection following CRISPR/Cas9 Mutagenesis using High-resolution Melt Analysis in the Mosquito Aedes aegypti
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Indel Detection following CRISPR/Cas9 Mutagenesis using High-resolution Melt Analysis in the Mosquito Aedes aegypti

Published on: September 10, 2021

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Considerations for homology-based DNA repair in mosquitoes: Impact of sequence heterology and donor template source

Joshua Xin De Ang1, Katherine Nevard1, Rebekah Ireland1

  • 1The Pirbright Institute, Pirbright, Woking, United Kingdom.

Plos Genetics
|February 18, 2022
PubMed

Insights

Sequence mismatches and donor template types significantly impact gene editing in Aedes aegypti mosquitoes. Understanding homology-directed repair (HDR) is crucial for developing effective mosquito control strategies against vector-borne diseases.

Area of Science:

  • Genetics and Genomics
  • Molecular Biology
  • Vector Control

Background:

  • Insecticide resistance and vector-borne diseases necessitate novel mosquito control methods.
  • Aedes aegypti is a primary vector for arboviruses, but Cas9-based knock-in integration rates are currently low.
  • Understanding homology-directed repair (HDR) is critical for improving gene editing efficiency in Aedes aegypti.

Purpose of the Study:

  • To investigate the impact of sequence mismatches and different donor template forms on HDR-mediated integration rates in Aedes aegypti.
  • To characterize gene conversion patterns following successful knock-in events.

Main Methods:

  • Assessed integration rates using various donor template forms (plasmid, ssDNA, biotinylated ds/ssDNA).
  • Introduced varying degrees of sequence dissimilarity (heterology) between homology arms and the genomic target.
  • Sequenced transgene flanking regions to analyze gene conversion tract characteristics.

Main Results:

  • A 1.2% nucleotide dissimilarity between homology arms and the target significantly reduced integration rates.
  • Plasmid donors resulted in 59-88% canonical HDR events, while other donor types yielded no canonical integrations.
  • Canonical integration conversion tracts were predominantly unidirectional (60%) up to 220 bp, with some bidirectional events up to 725 bp.

Conclusions:

  • Optimizing donor template design and minimizing sequence heterology are essential for enhancing gene editing efficiency in Aedes aegypti.
  • The findings provide insights into HDR mechanisms in Aedes aegypti, informing future vector control strategies.
  • Characterization of gene conversion tracts aids in understanding the limitations and potential of HDR-based approaches.

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