Regulation of ecdysis by Orcokinin neuropeptides in the kissing bug Rhodnius prolixus

ONS SHEILA

Orlando

Congreso; International Congress of Entomology; 2016

Entomological Society of America

p { margin-bottom: 0.25cm; direction: ltr; line-height: 120%; text-align: justify; }Introduction:Stereotyped innate behaviors occurringduring ecdysis are regulated by neuropeptidic pathways; the membersof this pathway are better characterized in crustacean andholometabola than in hemimetabola. Inthe recent years, the combination of genomic, transcriptomic andpeptidomic information boosted the identification of regulatorymolecules in many insect species, many of them could be involved inecdysis regulation. Orcokinins are neuropeptides conserved in mostinsect species, but whose role in physiological regulation is barelystudied. We provide evidence of their important role in theregulation of ecdysis in the hemimetabolous insect Rhodniusprolixus. Methods:We used RNAi technique to silence theexpression of neuropeptide precursors involved in ecdysis in thekissing bug Rhodniusprolixus.We also studied the expression pattern of these genes in differenttissues and throughout the days from blood feeding until ecdysis. Results/Conclusion:Whenever the expression of Orcokiningene is silenced in the hemimetabolous insect Rhodniusprolixus the individuals are not ableto complete molting, and they die at the expected moment of ecdysis.The silencing of Orcokinin gene affects the expression of classicalecdysis hormones as Corazonin, EH, ETH and CCAP. Our results indicatea central role of Orcokinins in the hormonal regulation of ecdysis inRhodnius prolixus.Our and previous data suggest a conserved role of Orcokinins in theregulation of innate behaviors in insects.