Immunity and other defenses in pea aphids, Acyrthosiphon pisum

• Type of Material: Article
• Authors: Seth M. Barribeau, Emory University; Martin de Vos, Boyce Thompson Institute for Plant Research; Elizabeth J. Duncan, University of Otago; Jay D. Evans, USDA-ARS Bee Research Lab; Toni Gabaldon, Centre for Genomic Regulation; Murad Ghanim, The Volcani Center; Adelaziz Heddi, Université de Lyon; Isgouhi Kaloshian, University of California; Amparo Latorre, Universitat de València; Andres Moya, Universitat de València; Atsushi Nakabachi, RIKEN; Benjamin J. Parker, Emory University; Vincente Perez-Brocal, Université de Lyon; Miguel Pignatelli, Universitat de València; Yvan Rahbé, Université de Lyon; John S. Ramsey, Boyce Thompson Institute for Plant Research; Chelsea J. Spragg, Emory University; Javier Tamames, Universitat de València; Daniel Tamarit, Universitat de València; Cecilia Tamborindeguy, Cornell University; Caroline Vincent-Monegat, Université de Lyon; Andreas Vilcinskas, Justus-Liebig-University of Giessen; Nicole Marie Gerardo, Emory University; Boran Altincicek, Justus-Liebig-University of Giessen; Caroline Anselme, Université de Lyon; Hagop Atamian, University of California
• Language: English
• Date: 2010-02-23
• Publisher: BioMed Central
• Publication Version: Final Published Version
• Copyright Statement: © 2010 Gerardo et al.; licensee BioMed Central Ltd.
• License: Creative Commons Attribution 2.0 Generic
• Final Published Version (URL): http://genomebiology.com/2010/11/2/R21
• Title of Journal or Parent Work: Genome Biology
• ISSN: 1465-6906
• Volume: 11
• Issue: 2
• Start Page: 1
• End Page: 17
• Grant/Funding Information: Comparison with M. persicae was supported by USDA grant 2005-35604-15446 to Georg Jander.
• Research Categories: Biology, Genetics; Biology, Entomology

Abstract

Background: Recent genomic analyses of arthropod defense mechanisms suggest conservation of key elements underlying responses to pathogens, parasites and stresses. At the center of pathogen-induced immune responses are signaling pathways triggered by the recognition of fungal, bacterial and viral signatures. These pathways result in the production of response molecules, such as antimicrobial peptides and lysozymes, which degrade or destroy invaders. Using the recently sequenced genome of the pea aphid (Acyrthosiphon pisum), we conducted the first extensive annotation of the immune and stress gene repertoire of a hemipterous insect, which is phylogenetically distantly related to previously characterized insects models. Results: Strikingly, pea aphids appear to be missing genes present in insect genomes characterized to date and thought critical for recognition, signaling and killing of microbes. In line with results of gene annotation, experimental analyses designed to characterize immune response through the isolation of RNA transcripts and proteins from immune-challenged pea aphids uncovered few immune-related products. Gene expression studies, however, indicated some expression of immune and stress-related genes. Conclusions: The absence of genes suspected to be essential for the insect immune response suggests that the traditional view of insect immunity may not be as broadly applicable as once thought. The limitations of the aphid immune system may be representative of a broad range of insects, or may be aphid specific. We suggest that several aspects of the aphid life style, such as their association with microbial symbionts, could facilitate survival without strong immune protection.