PcEiger links the Imd/Relish pathway to ROS production in the intestine of the red swamp crayfish

EMBO Rep. 2023 May 4;24(5):e55903. doi: 10.15252/embr.202255903. Epub 2023 Mar 28.


In the arthropod gut, commensal microbiota maintain the immune deficiency (Imd)/Relish pathway for expression of antimicrobial peptides, whereas pathogenic bacteria induce dual oxidase 2 (Duox2) for production of extracellular microbicidal reactive oxygen species (ROS). The Imd/Relish pathway and the Duox2/ROS system are regarded as independent systems. Here, we report that these two systems are bridged by the tumor necrosis factor (TNF) ortholog PcEiger in the red swamp crayfish Procambarus clarkii. PcEiger expression is induced by commensal bacteria or the Imd/Relish pathway. PcEiger knockdown alters bacterial abundance and community composition due to variations in the oxidative status of the intestine. PcEiger induces Duox2 expression and ROS production by regulating the activity of the transcription factor Atf2. Moreover, PcEiger mediates regulation of the Duox2/ROS system by commensal bacteria and the Imd/Relish pathway. Our findings suggest that the Imd/Relish pathway regulates the Duox2/ROS system via PcEiger in P. clarkii, and they provide insights into the crosstalk between these two important mechanisms for arthropod intestinal immunity.

Keywords: Relish; arthropod; dual oxidase 2; intestine; reactive oxygen species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astacoidea* / metabolism
  • Astacoidea* / microbiology
  • Dual Oxidases / genetics
  • Immunity, Innate
  • Intestines
  • Reactive Oxygen Species
  • Transcription Factors* / metabolism


  • Reactive Oxygen Species
  • Dual Oxidases
  • Transcription Factors