1,721,054 research outputs found
Exploring the immune resilience of Mediterranean mussels: Recent advances and future directions
Full text linkThe Mediterranean mussel (Mytilus galloprovincialis) is a key species in European aquaculture, known for its economic and societal importance, particularly as a primary source of income for local fisheries in European coastal areas. While historically resilient to the mass mortality events that have affected other bivalve species, M. galloprovincialis may face increasing threats from emerging pathogens, including bacteria, viruses, and eukaryotic parasites. These microorganisms, often opportunistic, pose heightened risks in the current climate change scenario, where heatwaves are becoming increasingly frequent and the persistent presence of pollutants is suspected to impair the functional response of hemocytes. Over the past decade, significant advancements in immunological research have provided deeper insights into the cellular and molecular mechanisms underlying the robust defense system of M. galloprovincialis, which allows this species to efficiently cope with a broad range of infections. By analyzing the scientific literature published on mussel immunology over the past ten years, this review consolidates current knowledge on the immune system of the Mediterranean mussel. We place a particular focus on the cellular and molecular components involved in the recognition and elimination of microbial pathogens and discuss how the most recent discoveries may inform improved management and disease mitigation strategies for Mediterranean mussel farming in the in the years to come
An updated molecular basis for mussel immunity
Full text linkNon-self recognition with the consequent tolerance or immune reaction is a crucial process to succeed as living organisms. At the same time the interactions between host species and their
microbiome, including potential pathogens and parasites, significantly contribute to animal life
diversity. Marine filter-feeding bivalves, mussels in particular, can survive also in heavily anthropized coastal waters despite being constantly surrounded by microorganisms. Based on the first outline of the Mytilus galloprovincialis immunome dated 2011, the continuously growing transcript data and the
recent release of a draft mussel genome, we explored the available sequence data and scientific literature to reinforce our knowledge on the main gene-encoded elements of the mussel immune responses, from the pathogen recognition to its clearance. We carefully investigated molecules specialized in the sensing and targeting of potential aggressors, expected to show greater molecular diversification, and outlined, whenever relevant, the interconnected cascades of the intracellular signal
transduction. Aiming to explore the diversity of extracellular, membrane-bound and intracellular pattern recognition receptors in mussel, we updated a highly complex immune system, comprising molecules which are described here in detail for the first time (e.g. NOD-like receptors) or which had only been partially characterized in bivalves (e.g. RIG-like receptors). Overall, our comparative sequence analysis supported the identification of over 70 novel full-length immunity-related transcripts in M. galloprovincialis. Nevertheless, the multiplicity of gene functions relevant to immunity, the involvement of part of them in other vital processes, and also the lack of a refined mussel genome make this work still not-exhaustive and support the development of more specific studies
The complex evolutionary history of sulfoxide synthase in ovothiol biosynthesis
No full textSulfoxide synthases are enzymes involved in the biosynthesis of small sulfur-containing natural products. Their enzymatic activity represents a unique sulfur transfer strategy in nature that is the insertion of a sulfur atom on the imidazole ring of histidine. To date, only two enzymes are known to carry out this function: The sulfoxide synthase EgtB, involved in the biosynthesis of ergothioneine in fungi and bacteria, and the 5-histidylcysteine sulfoxide synthase OvoA, involved in the biosynthesis of ovothiols, found in the eggs and biological fluids of marine invertebrates, some proteobacteria and protists. In particular, ovothiols, thanks to their unique redox properties, are probably the most intriguing marine sulfur-containing molecules. Although they have long been considered as cellular protective molecules, new evidence suggest that their biological activities and ecological role might be more complex than originally thought. Here, we investigate the evolutionary history of OvoA in Metazoa, reporting its monophyletic ancient origins, which could be traced back to the latest common ancestor of Choanozoa. Nevertheless, we show that OvoA is missing in several major extant taxa and we discuss this patchy distribution in the light of the massive genome reduction events documented in Metazoa. We also highlight two interesting cases of secondary acquisition through horizontal gene transfer, which occurred in hydrozoans and bdelloid rotifers. The evolutionary success of this metabolic pathway is probably ascribable to its role in the maintenance of cellular redox homeostasis, which enables organisms to survive in different environmental niches
Helminthic host defense peptides: using the parasite to defend the host
No full text: Parasitic helminths are destined to share niches with a variety of microbiota that inevitably influence their interaction with the host. To modulate the microbiome for their benefit and defend against pathogenic isolates, helminths have developed host defense peptides (HDPs) and proteins as integral elements of their immunity. These often exert a relatively nonspecific membranolytic activity toward bacteria, sometimes with limited or no toxicity toward host cells. With a few exceptions, such as nematode cecropin-like peptides and antibacterial factors (ABFs), helminthic HDPs are largely underexplored. This review scrutinizes current knowledge on the repertoire of such peptides in helminths and promotes their research as potential leads for an anti-infective solution to the burgeoning problem of antibiotic resistance
Characterization of Mytimacin-1, a novel cationic antimicrobial peptide in the Mediterranean mussel Mytilus galloprovincialis
No full textThe genome of the Pacific oyster Crassostrea gigas brings new insights on the massive expansion of the C1q gene family in Bivalvia
Full text linkC1q domain-containing (C1qDC) proteins are regarded as important players in the innate immunity of bivalve mollusks and other invertebrates and their highly adaptive binding properties indicate them as efficient pathogen recognition molecules. Although experimental studies support this view, the molecular data available at the present time are not sufficient to fully explain the great molecular diversification of this family, present in bivalves with hundreds of C1q coding genes. Taking advantage of the fully sequenced genome of the Pacific oyster Crassostrea gigas and more than 100 transcriptomic datasets, we: (i) re-annotated the oyster C1qDC loci, thus identifying the correct genomic
organization of 337 C1qDC genes, (ii) explored the expression pattern of oyster C1qDC genes in diverse developmental stages and adult tissues of unchallenged and experimentally treated animals; (iii) investigated the expansion of the C1qDC gene family in all major bivalve subclasses. Overall, we provide a broad description of the functionally relevant features of oyster C1qDC genes, their comparative expression levels and new evidence confirming that a gene family expansion event has occurred during the course of Bivalve evolution, leading to the diversification of hundreds of different C1qDC genes in both the Pteriomorphia and Heterodonta subclasses
Myticalins: a novel family of linear cationic AMPs from Mytilus galloprovincialis identified by de novo bioinformatic analysis
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
