The extraembryonic serosa is a frontier epithelium providing the insect egg with a full-range innate immune response

• DOI: 10.7554/elife.04111
• Publication Date: 2014-12-04T10:44:31Z
• Authors: Chris G C Jacobs; Herman P Spaink; Maurijn van der Zee
• Keywords: 0301 basic medicine; QH301-705.5; Science; Colony Count, Microbial; Extraembryonic Membranes; Genes, Insect; Epithelium; Tribolium castaneum; 03 medical and health sciences; Serous Membrane; Sepsis; Animals; NF-kappaB; Biology (General); innate immunity; Toll; In Situ Hybridization; Ovum; Tribolium; Reverse Transcriptase Polymerase Chain Reaction; Sequence Analysis, RNA; Q; R; Gene Expression Regulation, Developmental; Reproducibility of Results; RNA sequencing; Immunity, Innate; 3. Good health; Developmental Biology and Stem Cells; Medicine; RNA Interference; serosa; Antimicrobial Cationic Peptides

Drosophila larvae and adults possess a potent innate immune response, but the response of eggs is poor. In contrast to Drosophila, beetle Tribolium are protected by serosa, an extraembryonic epithelium that present in all insects except higher flies. this study, we test possible function frontier using Tc-zen1 RNAi-mediated deletion. First, show bacteria propagate twice as fast serosa-less eggs. Then, compare complete transcriptomes wild-type, control RNAi, RNAi before after sterile or septic injury. Infection induces genes involved Toll IMD-signaling, melanisation, production reactive oxygen species antimicrobial peptides wild-type not Finally, demonstrate constitutive induced gene expression serosal situ hybridization. We conclude serosa provides insect with full-range response.