title: Mode of action of methoprene in affecting female reproduction in the African malaria mosquito, Anopheles gambiae.
abstract: BACKGROUND
  One of the most studied actions of juvenile hormone (JH) is its ability to modulate ecdysteroid signaling during insect development and metamorphosis. Previous studies in mosquitoes showed that 20-hydroxyecdysone (20E) regulates vitellogenin synthesis. However, the action of JH and its mimics, e.g. methoprene, on female reproduction of mosquitoes remains unknown.
  
  
  RESULTS
  Here, a major malaria vector, Anopheles gambiae Giles, was used as a model insect to study the action of methoprene on female reproduction. Ecdysteroid titers and expression profiles of ecdysone-regulated genes were determined before and after a blood meal. An ecdysteroid peak was detected at 12 h post blood meal (PBM). The maximum expression of ecdysone-regulated genes, such as ecdysone receptor (EcR), hormone receptor 3 (HR3) and vitellogenin (Vg) gene, coincided with the ecdysteroid peak. Interestingly, topical application of methoprene at 6 h PBM delayed ovarian development and egg maturation by suppressing the expression of ecdysone-regulated genes in female mosquitoes.
  
  
  CONCLUSIONS
  The data suggest that ecdysteroid titers are correlated with Vg synthesis, and methoprene affects vitellogenesis by modulating ecdysteroid action in A. gambiae.
authors: Department of Entomology, University of Kentucky, Lexington, KY 40546, USA.
authors: Hua
authors: H
authors: Bai
authors: Dale B
authors: DB
authors: Gelman
authors: Subba R
authors: SR
authors: Palli
mesh_terms: D000818:Animals; D000852:Anopheles / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D001769:Blood; D004032:Diet / Q000662:veterinary; D015536:Down-Regulation / Q000187:drug effects; D004440:Ecdysone / Q000378:metabolism; D005247:Feeding Behavior / Q000502:physiology; D005260:Female; D020869:Gene Expression Profiling; D007303:Insect Vectors / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008288:Malaria / Q000635:transmission; D008726:Methoprene / Q000494:pharmacology*; D010063:Ovum / Q000187:drug effects / Q000254:growth & development; D051381:Rats; D012098:Reproduction / Q000187:drug effects / Q000235:genetics; D013997:Time Factors; D014818:Vitellogenesis / Q000187:drug effects / Q000235:genetics; D014819:Vitellogenins / Q000235:genetics
chemical_list: D014819:Vitellogenins; D004440:Ecdysone; D008726:Methoprene