Transcriptomic response of Manduca sexta immune tissues to parasitization by the bracovirus associated wasp Cotesia congregata. (July 2015)

• Record Type: Journal Article
• Authors: Chevignon, Germain; Cambier, Sébastien; Da Silva, Corinne; Poulain, Julie; Drezen, Jean-Michel; Huguet, Elisabeth; Moreau, Sébastien J.M.
• Is Part Of: Insect biochemistry and molecular biology. Volume 62(2015:Jul.)
• Page Start: 86
• Page End: 99
• Publication Date: 2015-07
• Subjects: Parasitoid -- Polydnavirus -- Transcriptome -- 454 sequencing -- Manduca sexta -- Antimicrobial peptide -- Innate immunity; PDV Polydnavirus -- CcBV Cotesia congregata bracovirus -- BV Bracovirus -- PO Phenoloxidase -- AMP Antimicrobial peptides -- PGRP Peptidoglycan recognition protein -- βGRP β1, 3-Glucan recognition protein -- IML Immulectin -- HP Hemolymph proteinase -- PAP Pro-phenoloxidase activating proteinase -- SPH Serine protease homologue -- RPKM Reads per kilobase per million -- CDS coding DNA sequences -- HAIP Hemocyte aggregation inhibitor protein precursor -- MIF Macrophage migration inhibitor factor -- ROS Reactive oxygen species -- HTIF host translation inhibitory factor -- JH Juvenile hormone -- JHBP Juvenile hormone binding protein -- JHE Juvenile hormone esterase; Insect biochemistry -- Periodicals; Insects -- Physiology -- Periodicals; Insects -- Molecular aspects -- Periodicals; Biochemistry -- Periodicals; Insectes -- Biochimie -- Périodiques; Insectes -- Composition -- Périodiques; Insectes -- Physiologie -- Périodiques; Insectes -- Aspect moléculaire -- Périodiques; Biochimie -- Périodiques; Biochemistry; Insect biochemistry; Insects -- Molecular aspects; Insects -- Physiology; Periodicals; 572.8157
• DOI: 10.1016/j.ibmb.2014.12.008
• Languages: English
• ISSNs: 0965-1748

Abstract

Abstract: During oviposition, Cotesia congregata parasitoid wasps inject into their host, Manduca sexta, some biological factors such as venom, ovarian fluid and a symbiotic polydnavirus (PDV) named Cotesia congregata bracovirus (CcBV). During parasitism, complex interactions occur between wasp-derived factors and host targets that lead to important modifications in host physiology. In particular, the immune response leading to wasp egg encapsulation is inhibited allowing wasp survival. To date, the regulation of host genes during the interaction had only been studied for a limited number of genes. In this study, we analysed the global impact of parasitism on host gene regulation 24 h post oviposition by high throughput 454 transcriptomic analyses of two tissues known to be involved in the host immune response (hemocytes and fat body). To identify specific effects of parasitism on host transcription at this time point, transcriptomes were obtained from non-treated and parasitized larvae, and also from larvae injected with heat-killed bacteria and double stimulated larvae that were parasitized prior to bacterial challenge. Results showed that, immune challenge by bacteria leads to induction of certain antimicrobial peptide (AMP) genes in M. sexta larvae whether they were parasitized or not prior to bacterial challenge. These results show that at 24 h post oviposition pathways leading to expression of AMP genes are not all inactivated suggesting wasps are in an antiseptic environment. In contrast, at this time point genes involved in phenoloxidase activation and cellular immune responses were globally down-regulated after parasitism in accordance with the observed inhibition of wasp egg encapsulation. Graphical abstract: Highlights: Transcriptomic analysis of fat body and hemocytes of Manduca sexta larvae parasitized by Cotesia congregata was performed. Parasitism does not block the transcription of antimicrobial peptide genes in response to injection of heat-killed bacteria. Parasitism inhibits transcription of key genes involved in the phenoloxidase pathway and cellular immune response. Parasitism also impacts genes involved in oxidative stress, ribosome composition, hormone responses and metabolism.