CRISPR-Cas9 mediated dsRNase knockout improves RNAi efficiency in the fall armyworm

Jinmo Koo, Guan Heng Zhu, Subba Reddy Palli

Research output: Contribution to journalArticlepeer-review


Lepidopteran insects are refractory to RNA interference (RNAi) response, especially to orally delivered double-stranded RNA (dsRNA). High nuclease activity in the midgut lumen is proposed as one of the major reasons for RNAi insensitivity. We identified three dsRNase genes highly expressed in the midgut of fall armyworm (FAW), Spodoptera frugiperda. The genomic region harboring those three dsRNase genes was deleted using the CRISPR-Cas9-mediated genome editing method. A homozygous line with deletion of three dsRNase genes was produced. dsRNA degradation by midgut lumen contents of mutant larvae was lower than in wild-type larvae. Feeding dsRNA targeting the inhibitor of apoptosis (IAP) gene increased knockdown of the target gene and mortality in mutants compared to wild-type larvae. These results suggest that dsRNases in the midgut contribute to RNAi inefficiency in FAW. Formulations that protect dsRNA from dsRNase degradation may improve RNAi efficiency in FAW and other lepidopteran insects.

Original languageEnglish
Article number105839
JournalPesticide Biochemistry and Physiology
StatePublished - Mar 2024

Bibliographical note

Publisher Copyright:
© 2023


  • Genome editing
  • Midgut
  • Nuclease
  • Spodoptera frugiperda
  • dsRNA stability

ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Health, Toxicology and Mutagenesis


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