Silencing an Anopheles gambiae catalase and sulfhydryl oxidase increases mosquito mortality after a blood meal

T. Magalhaes, D. E. Brackney, J. C. Beier, B. D. Foy

Research output: Contribution to journalArticlepeer-review

34 Scopus citations


Catalase is a potent antioxidant, likely involved in post-blood meal homeostasis in mosquitoes. This enzyme breaks down H2O2, preventing the formation of the hydroxyl radical (HO). Quiescins are newly classified sulfhydryl oxidases that bear a thioredoxin motif at the N-terminal and on ERV1-like portion at the C-terminal. These proteins have a major role in generating disulfides in intra- or extracellular environments, and thus participate in redox reactions. In the search for molecules to serve as targets for novel anti-mosquito strategies, we have silenced a catalase and a putative quiescin/sulfhydryl oxidase (QSOX), from the African malaria vector Anopheles gambiae, through RNA interference (RNAi) experiments. We observed that the survival of catalase- and QSOX-silenced insects was reduced over controls following blood digestion, most likely due to the compromised ability of mosquitoes to scavenge and/or prevent damage caused by blood meal-derived oxidative stress. The higher mortality effect was more accentuated in catalase-silenced mosquitoes, where catalase activity was reduced to low levels. Lipid peroxidation was higher in QSOX-silenced mosquitoes suggesting the involvement of this protein in redox homeostasis following a blood meal. This study points to the potential of molecules involved in antioxidant response and redox metabolism to serve as targets of novel anti-mosquito strategies and offers a screening methodology for finding fargetable mosquito molecules.

Original languageEnglish (US)
Pages (from-to)134-143
Number of pages10
JournalArchives of Insect Biochemistry and Physiology
Issue number3
StatePublished - Jul 2008


  • Antioxidant
  • Malaria
  • Mosquito
  • Redox metabolism
  • RNAi
  • Survival

ASJC Scopus subject areas

  • Insect Science
  • Physiology
  • Biochemistry
  • Biochemistry, Genetics and Molecular Biology(all)
  • Physiology (medical)


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