Transcriptomic Immune Response of Tenebrio molitor Pupae to Parasitization by Scleroderma guani

Abstract

BackgroundHost and parasitoid interaction is one of the most fascinating relationships of insects, which is currently receiving an increasing interest. Understanding the mechanisms evolved by the parasitoids to evade or suppress the host immune system is important for dissecting this interaction, while it was still poorly known. In order to gain insight into the immune response of Tenebrio molitor to parasitization by Scleroderma guani, the transcriptome of T. molitor pupae was sequenced with focus on immune-related gene, and the non-parasitized and parasitized T. molitor pupae were analyzed by digital gene expression (DGE) analysis with special emphasis on parasitoid-induced immune-related genes using Illumina sequencing.Methodology/Principal FindingsIn a single run, 264,698 raw reads were obtained. De novo assembly generated 71,514 unigenes with mean length of 424 bp. Of those unigenes, 37,373 (52.26%) showed similarity to the known proteins in the NCBI nr database. Via analysis of the transcriptome data in depth, 430 unigenes related to immunity were identified. DGE analysis revealed that parasitization by S. guani had considerable impacts on the transcriptome profile of T. molitor pupae, as indicated by the significant up- or down-regulation of 3,431 parasitism-responsive transcripts. The expression of a total of 74 unigenes involved in immune response of T. molitor was significantly altered after parasitization.Conclusions/Significanceobtained T. molitor transcriptome, in addition to establishing a fundamental resource for further research on functional genomics, has allowed the discovery of a large group of immune genes that might provide a meaningful framework to better understand the immune response in this species and other beetles. The DGE profiling data provides comprehensive T. molitor immune gene expression information at the transcriptional level following parasitization, and sheds valuable light on the molecular understanding of the host-parasitoid interaction.

Transcriptome sequencing and analysis of the coconut leaf beetle, Brontispa longissima

“…Most unigenes were shorter than 500 bp (55.48% of total), and only 26.21% of them were longer than 1000 bp, which is a similar result to that obtained in previous transcriptome analyses in different insects using Illumina ® sequencing (Zhu et al, 2012;Kumar et al, 2014). The large number of short-length unigenes generated might be due to the short length of the sequencing-read ability associated with the Illumina ® platform, and coverage of individual reads (Carvalho et al, 2010;Zhu et al, 2013b).…”

“…These reads were assembled into 58,815 contigs and 41,652 unigenes. The number of unigenes was in a range similar to that reported for other beetles, such as Holotrichia parallela, Meligethes aeneus, and Tenebrio molitor (Zhu et al, 2013b;Ju et al, 2014;Zimmer et al, 2014). The average lengths of the contigs and unigenes were 1449 and 932 bp, respectively.…”

Endogenous egg immune defenses in the yellow mealworm beetle (Tenebrio molitor)

“…This species is well known as a model for innate immunity (Chae et al, 2012;Dobson et al, 2012;Goltsev et al, 2009;Johnston et al, 2014;Lee et al, 1996;Moon et al, 1994;Park et al, 2007Park et al, , 2006Yu et al, 2010;Zhang et al, 2003;Zhu et al, 2013Zhu et al, , 2014, but has also received considerable attention with respect to TGIP (Dubuffet et al, 2015;Moreau et al, 2012;Moret, 2006;Zanchi et al, 2012). Here we show that the eggs of T. molitor can induce immune genes, including antimicrobial peptides (AMPs), to high levels upon bacterial challenge.…”

Identification of candidate chemosensory genes in the antennal transcriptome of Tenebrio molitor (Coleoptera: Tenebrionidae)

“…The three previously existing transcriptome datasets for T. molitor have been used to investigate either immune-related genetic response to pathogen challenge or the intestinal genes regulating ingestion of Bacillus thuringiensis protoxin (Oppert et al, 2012; Table S1. Johnston et al, 2013;Zhu et al, 2013). None have provided information on chemosensory genes.…”