Immune-Related Signaling in Mussel and Bivalves

A variety of signals and regulatory molecules coming from the exterior and interior environment significantly influence the vital cell processes and the overall organism responses in health and disease. The immune systems of invertebrates are amazingly diverse and, considering economically relevant bivalve spp., only a few pathways of intracellular signal transduction have been clearly and specifically associated to the innate immune responses (other signaling pathways are still fragmentary or not exclusive to the immune defense). Mainly based on DNA sequencing technologies and supported by functional analyses, not only the Toll/NF-kB, MAPKs and IL-17 signaling have been demonstrated to be present in Mytilus spp. and other bivalves but the identification of gene-encoded molecules expected to work as cytokines, hormons and neuropeptides reinforce the hypothesis of an ancient network between the immune and neuroendocrine systems. Although not exhaustive, this chapter aims to outline the current knowledge and research trends on the immune-related bivalve signaling.