Advances in understanding insect chitin biosynthesis.

Chitin, a natural polymer of N-acetylglucosamine chains, is a principal component of the apical extracellular matrix in arthropods. Chitin microfibrils serve as structural components of natural biocomposites present in the extracellular matrix of a variety of invertebrates including sponges, molluscs, nematodes, fungi and arthropods. In this review, we summarize the frontier advances of insect chitin synthesis.

Dextran sulfate sodium and uracil induce inflammatory effects and disrupt the chitinous peritrophic matrix in the midgut of Tribolium castaneum.

Dextran sulfate sodium is used in inflammatory bowel disease (IBD) mice models to trigger chronic intestinal inflammation. In this study, we have analyzed DSS effects in the genetic model and pest beetle, Tribolium castaneum, which can be easily and cost-effectively cultivated and examined in very large quantities compensating for individual variations. We fed the larvae with DSS and uracil, which is known to induce the production of reactive oxygen species by activating DUOX, a member of the NADPH oxidase family.

Analyses of ecdysteroid transporters in the fat body of Tribolium castaneum.

The control of insect moulting and metamorphosis involves ecdysteroids that orchestrate the execution of developmental genetic programs by binding to dimeric hormone receptors consisting of the ecdysone receptor (EcR) and ultraspiracle (USP). In insects, the main ecdysteroids comprise ecdysone (E), which is synthesized in the prothoracic gland and secreted into the haemolymph, and 20-hydroxyecdysone (20E), which is considered the active form by binding to the nuclear receptor of the target cell. While biosynthesis of ecdysteroids has been studied in detail in different insects, the transport systems involved in guiding these steroid hormones across cellular membranes have just recently begun to be studied.

High-throughput screening of caterpillars as a platform to study host-microbe interactions and enteric immunity.

Mammalian models of human disease are expensive and subject to ethical restrictions. Here, we present an independent platform for high-throughput screening, using larvae of the tobacco hornworm Manduca sexta, combining diagnostic imaging modalities for a comprehensive characterization of aberrant phenotypes. For validation, we use bacterial/chemical-induced gut inflammation to generate a colitis-like phenotype and identify significant alterations in morphology, tissue properties, and intermediary metabolism, which aggravate with disease progression and can be rescued by antimicrobial treatment.