title: Immune competence in insect eggs depends on the extraembryonic serosa.
abstract: Innate immunity is common to all metazoans and serves as a first line of defense against pathogens. Although the immune response of adult and larval insects has been well characterized, it remains unknown whether the insect egg is able to mount an immune response. Contrary to Drosophila, Tribolium eggs develop an extraembryonic epithelium, the serosa. Epithelia are well known for their ability to fight infection, so the serosa has the potential to protect the embryo against pathogens. To test this hypothesis we created serosa-less eggs by Tc-zen1 parental RNAi. We found that the Tribolium egg upregulates several immune genes to comparable levels as adults in response to infection. Drosophila eggs and serosa-less Tribolium eggs, however, show little to no upregulation of any of the tested immune genes. We conclude that the extraembryonic serosa is crucial for the early immune competence of the Tribolium egg.
authors.affiliation: Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, Netherlands.
authors.forename: Chris G C
authors.initials: CG
authors.lastname: Jacobs
authors.forename: Maurijn
authors.initials: M
authors.lastname: van der Zee
mesh_terms: D000818:Animals; D054807:Cecropins / Q000235:genetics; D023082:Defensins / Q000235:genetics; D004926:Escherichia coli / Q000276:immunology / Q000502:physiology; D005260:Female; D015870:Gene Expression / Q000235:genetics / Q000276:immunology*; D020869:Gene Expression Profiling; D017344:Genes, Insect / Q000235:genetics / Q000276:immunology*; D054884:Host-Pathogen Interactions / Q000276:immunology; D019476:Insect Proteins / Q000235:genetics; D016982:Micrococcus luteus / Q000276:immunology / Q000502:physiology; D010063:Ovum / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D020033:Protein Isoforms / Q000235:genetics; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012704:Serous Membrane / Q000196:embryology / Q000276:immunology* / Q000378:metabolism; D013045:Species Specificity; D014231:Tribolium / Q000235:genetics / Q000276:immunology* / Q000382:microbiology
chemical_list: D054807:Cecropins; D023082:Defensins; D019476:Insect Proteins; D020033:Protein Isoforms; C039711:attacin antibacterial protein, insect
keywords: Antimicrobial peptides (AMPs); Drosophila melanogaster; Innate immunity; Tc-zen1; Tribolium castaneum