Nevertheless, the MEGwB sequence includes a calycin domain that characterizes lipocalins and FABP genes. Lipocalins have been shown to be modulators of the immune response in vertebrates [65, 66], and an FABP protein has been seen to be active in cell proliferation caused by tumors [67]. Influence of symbiosis on host immune gene expression BAY 63-2521 in vitro In order to test whether the insect immune response to bacterial pathogens is influenced by symbiosis, we have compared immune

gene expression between symbiotic and aposymbiotic larvae. We have analyzed both larval responses to pricking stress (PBS injection) and to the challenge of the Gram-negative bacterium, E. coli (Fig. 4). Both symbiotic and aposymbiotic larvae were shown to respond slightly, but significantly, to an injection of PBS in the hemolymph. Induced genes included wpgrp2, wpgrp3, gnbp1, cactus, c-type lysozyme and all AMPs. When larvae were challenged with E. coli, all of these genes selleck (except cactus and c-type lysozyme) were highly induced, when compared with the mock-infected larvae. Concerning the impact of symbiosis on immune response efficiency, the stress generated by PBS injection did not induce any significant difference between symbiotic and aposymbiotic larvae at the transcriptional level for all the genes studied.

However, following infection with E. coli, Acesulfame Potassium aposymbiotic larvae displayed a higher expression of immune gene, when compared with symbiotic larvae (Fig. 4). Among the genes studied, wpgrp2, wpgrp3, the coleoptericin-B, the sarcotoxin and the diptericin were all significantly less induced in symbiotic insects than in aposymbiotic ones. Discussion and conclusion The last decade has seen a growing number of projects investigating the molecular and cellular interactions between invertebrate hosts and their symbionts [5–7, 30, 68–73]. These have focused on the immune (and bacterial) adaptive changes that favor the establishment of symbiosis [18, 70], the maintenance and control of symbiosis [6, 72, 74, 76], and the impacts of symbiosis

on host immunocompetence and fitness benefit [9, 77–82]. While recent data have provided original and exciting insights in these fields, much more effort needs to be deployed on the molecular and genetic aspects of find more additional invertebrate systems to unravel the conserved and diverged mechanisms in host-symbiont interactions. With this aim, we have first enlarged the gene repertoire of the cereal weevil S. oryzae and, secondly, we have used qRT-PCR to examine the expression of a set of genes in different conditions, taking into consideration the bacteriocyte molecular basis and symbiont impacts on the host immune response. Bioinformatic analyses of 26,886 EST sequences, from different libraries, have generated 8,941 unigenes.