Immune response by insect eggs to parasitism

• Applicant: Professorin Dr. Monika Hilker
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: from 2008 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 79070646

While insect larvae and adults are well known to show immune responses to parasitism, insect eggs have only recently been demonstrated to successfully cope with parasitoids by immune reactions. We showed that parasitization of Manduca sexta eggs by the parasitoid Trichogramma evanescens induces quickly transcription of some immune relevant genes, while others are first suppressed and induced later. About 36% of parasitized M. sexta eggs were found to survive parasitism. Previous studies by other labs showed that immune challenging of insect larvae or adults may positively affect immune responses to later challenges. Little is known about the mechanisms of such immune priming” effects. Neither is known whether immune responses of insect eggs can be affected by such priming . This project aims to elucidate (1) whether an immune challenge of M. sexta females affects immune responses of their eggs to parasitism. Further studies will address the question whether an immune challenge of eggs can result in priming effects on immune responses to later challenges. We will investigate the questions (2) whether parasitization of young M. sexta eggs by T. evanescens affects immune responses to further egg parasitism (superparasitism), and (3) whether M. sexta larvae that survived egg parasitism show other immune reactions to larval parasitization by Cotesia congregata than larvae that have not been challenged by egg parasitoids during their embryonic development. Immune responses will be studied by determination of transcription levels of immune relevant genes by quantitative real time RT-PCR.

• DFG Programme: Research Grants
• Participating Person: Dr. Mohatmed Abdel-latief