RESUMO
Evolutionary perspectives on the deployment of immune factors following infection have been shaped by studies on a limited number of biomedical model systems with a heavy emphasis on vertebrate species. Although their contributions to contemporary immunology cannot be understated, a broader phylogenetic perspective is needed to understand the evolution of immune systems across Metazoa. In our study, we leverage differential gene expression analyses to identify genes implicated in the antiviral immune response of the acorn worm hemichordate, Saccoglossus kowalevskii, and place them in the context of immunity evolution within deuterostomes-the animal clade composed of chordates, hemichordates, and echinoderms. Following acute exposure to the synthetic viral double-stranded RNA analog, poly(I:C), we show that S. kowalevskii responds by regulating the transcription of genes associated with canonical innate immunity signaling pathways (e.g., nuclear factor κB and interferon regulatory factor signaling) and metabolic processes (e.g., lipid metabolism), as well as many genes without clear evidence of orthology with those of model species. Aggregated across all experimental time point contrasts, we identify 423 genes that are differentially expressed in response to poly(I:C). We also identify 147 genes with altered temporal patterns of expression in response to immune challenge. By characterizing the molecular toolkit involved in hemichordate antiviral immunity, our findings provide vital evolutionary context for understanding the origins of immune systems within Deuterostomia.
Assuntos
Cordados não Vertebrados , Cordados , Animais , Filogenia , Antivirais , Vertebrados , Equinodermos , Cordados não Vertebrados/genéticaRESUMO
Deep-sea ophiuroids from western Mexico have been documented since 1899, but mostly by non-Mexican expeditions. TALUD is a Mexican project designed to study the deep-sea fauna from Mexico. As part of it, the present contribution provides for the first time detailed information about the taxonomy and distribution, as well as images, of deep-sea ophiuroids from western Mexico, representing a useful taxonomic identification tool for Ophiuroidea from the eastern Pacific. A total of 38 species of ophiuroid (35 identified at species level, one at genus level, and two as confer) were collected from 83 stations located at 123â2,309 m depth. At a regional scale, several new species records are presented: six for western Baja California, five for western Baja California Sur, two for the Gulf of California, four for Jalisco, 14 for Colima, and five for Guerrero. Geographic (six) and bathymetric (seven) distribution ranges of species are extended. An updated list of deep-sea ophiuroids (61 species) from western Mexico is provided together with an identification key to species collected during this survey. In addition, nine records of deep-sea ophiuroids for the Mexican Pacific are unproven, doubtful or invalid. We corroborated the presence of Ophiacantha eurypoma and Ophiacantha pacifica in the study area and added Amphiura gymnogastra as the first record for Mexico. We propose to transfer Ophiacantha phragma to Ophiolimna on account of it having both granules and spines on the dorsal disc and striated arm plates. TALUD cruises collected 57 % of the total deep-sea species known to occur off Mexico, making it the most important survey of deep-sea Ophiuroidea carried out in western Mexico to date.
Assuntos
Equinodermos , Animais , MéxicoRESUMO
Comparative study of macrofaunal assemblages in seagrass meadows and neighboring seabeds along the southeastern coast of Shandong Peninsula, China were performed. A total of 136 species were identified, including polychaetes (49 species), crustaceans (28), molluscs (58), and echinoderms (1). Species numbers of macrofauna in seagrass meadows and the neighboring seabeds were 52 and 65, respectively, whereas those in autumn were 90 and 56, respectively. Average macrofaunal abundances in spring in seagrass and neighboring seabeds were 2388.9 and 2516.7 ind./m2, respectively, whereas those in autumn were 11,689.0 and 1733.3 ind./m2, respectively. Ranges of species richness index, evenness index, and Shannon-Wiener index in seagrass meadows and the neighboring seabeds were 1.3-2.7, 0.7-0.9, 2.8-3.8, and 1.04-2.4, 0.5-0.9, 1.6-3.4 during spring, whereas those in autumn were 0.1-4.2, 0.3-0.8, 0.8-3.6 and 1.4-3.5, 0.5-0.9, 2.2-4.5. Bottom water temperature, salinity, sediment chlorophyll a concentration, and water content were the most important environmental factors influencing macrofaunal assemblages.
Assuntos
Equinodermos , Ecossistema , Animais , Clorofila A , Água , ChinaRESUMO
The remarkably complex skeletal systems of the sea stars (Echinodermata, Asteroidea), consisting of hundreds to thousands of individual elements (ossicles), have intrigued investigators for more than 150 years. While the general features and structural diversity of isolated asteroid ossicles have been well documented in the literature, the task of mapping the spatial organization of these constituent skeletal elements in a whole-animal context represents an incredibly laborious process, and as such, has remained largely unexplored. To address this unmet need, particularly in the context of understanding structure-function relationships in these complex skeletal systems, we present an integrated approach that combines micro-computed tomography, automated ossicle segmentation, data visualization tools, and the production of additively manufactured tangible models to reveal biologically relevant structural data that can be rapidly analyzed in an intuitive manner. In the present study, we demonstrate this high-throughput workflow by segmenting and analyzing entire skeletal systems of the giant knobby star, Pisaster giganteus, at four different stages of growth. The in-depth analysis, presented herein, provides a fundamental understanding of the three-dimensional skeletal architecture of the sea star body wall, the process of skeletal maturation during growth, and the relationship between skeletal organization and morphological characteristics of individual ossicles. The widespread implementation of this approach for investigating other species, subspecies, and growth series has the potential to fundamentally improve our understanding of asteroid skeletal architecture and biodiversity in relation to mobility, feeding habits, and environmental specialization in this fascinating group of echinoderms.
Assuntos
Visualização de Dados , Estrelas-do-Mar , Animais , Estrelas-do-Mar/anatomia & histologia , Estrelas-do-Mar/química , Microtomografia por Raio-X , EquinodermosRESUMO
The mutable collagenous tissue (MCT) of echinoderms has the capacity to undergo changes in its tensile properties within a timescale of seconds under the control of the nervous system. All echinoderm autotomy (defensive self-detachment) mechanisms depend on the extreme destabilisation of mutable collagenous structures at the plane of separation. This review illustrates the role of MCT in autotomy by bringing together previously published and new information on the basal arm autotomy plane of the starfish Asterias rubens L. It focuses on the MCT components of breakage zones in the dorsolateral and ambulacral regions of the body wall, and details data on their structural organisation and physiology. Information is also provided on the extrinsic stomach retractor apparatus whose involvement in autotomy has not been previously recognised. We show that the arm autotomy plane of A. rubens is a tractable model system for addressing outstanding problems in MCT biology. It is amenable to in vitro pharmacological investigations using isolated preparations and provides an opportunity for the application of comparative proteomic analysis and other "-omics" methods which are aimed at the molecular profiling of different mechanical states and characterising effector cell functions.
Assuntos
Asterias , Equinodermos , Animais , Estrelas-do-Mar , Asterias/anatomia & histologia , Proteômica , Modelos BiológicosRESUMO
The catch connective, or mutable collagenous, tissue of echinoderms changes its mechanical properties in response to stimulation. The body wall dermis of sea cucumbers is a typical catch connective tissue. The dermis assumes three mechanical states: soft, standard, and stiff. Proteins that change the mechanical properties have been purified from the dermis. Tensilin and the novel stiffening factor are involved in the soft to standard and standard to stiff transitions, respectively. Softenin softens the dermis in the standard state. Tensilin and softenin work directly on the extracellular matrix (ECM). This review summarizes the current knowledge regarding such stiffeners and softeners. Attention is also given to the genes of tensilin and its related proteins in echinoderms. In addition, we provide information on the morphological changes of the ECM associated with the stiffness change of the dermis. Ultrastructural study suggests that tensilin induces an increase in the cohesive forces with the lateral fusion of collagen subfibrils in the soft to standard transition, that crossbridge formation between fibrils occurs in both the soft to standard and standard to stiff transitions, and that the bond which accompanies water exudation produces the stiff dermis from the standard state.
Assuntos
Derme , Equinodermos , Animais , Derme/metabolismo , Equinodermos/metabolismo , Tecido Conjuntivo/metabolismo , Colágeno/metabolismo , Matriz Extracelular/metabolismoRESUMO
Echinoderms have been attracting increasing attention for their polysaccharides, with unique chemical structure and enormous potential for preparing drugs to treat diseases. In this study, a glucan (TPG) was obtained from the brittle star Trichaster palmiferus. Its structure was elucidated by physicochemical analysis and by analyzing its low-molecular-weight products as degraded by mild acid hydrolysis. The TPG sulfate (TPGS) was prepared, and its anticoagulant activity was investigated for potential development of anticoagulants. Results showed that TPG consisted of a consecutive α1,4-linked D-glucopyranose (D-Glcp) backbone together with a α1,4-linked D-Glcp disaccharide side chain linked through C-1 to C-6 of the main chain. The TPGS was successfully prepared with a degree of sulfation of 1.57. Anticoagulant activity results showed that TPGS significantly prolonged activated partial thromboplastin time, thrombin time, and prothrombin time. Furthermore, TPGS obviously inhibited intrinsic tenase, with an EC50 value of 77.15 ng/mL, which was comparable with that of low-molecular-weight heparin (LMWH) (69.82 ng/mL). TPGS showed no AT-dependent anti-FIIa and anti-FXa activities. These results suggest that the sulfate group and sulfated disaccharide side chains play a crucial role in the anticoagulant activity of TPGS. These findings may provide some information for the development and utilization of brittle star resources.
Assuntos
Anticoagulantes , Glucanos , Animais , Anticoagulantes/farmacologia , Anticoagulantes/química , Sulfatos/química , Heparina de Baixo Peso Molecular , Equinodermos , Polissacarídeos/farmacologia , Tempo de Tromboplastina ParcialRESUMO
Owing to their remarkable physical properties, cellular structures, such as triply periodic minimal surfaces (TPMS), have multidisciplinary and multifunctional applications. Although these structures are observed in nature, examples of TPMS with large length scales in living organisms are exceedingly rare. Recently, microstructure reminiscent of the diamond-type TPMS was documented in the skeleton of the modern knobby starfish Protoreaster nodosus. Here we report a similar microlattice in a 385 Myr old crinoid Haplocrinites, which pushes back the origins of this highly ordered microstructure in echinoderms into the Devonian. Despite the low Mg2+/Ca2+ ratio of the 'calcite' Devonian sea, the skeleton of these crinoids has high-Mg content, which indicates strong biological control over biomineralogy. We suggest that such an optimization of trabecular arrangement additionally enriched in magnesium, which enhances the mechanical properties, might have evolved in these crinoids in response to increased predation pressure during the Middle Palaeozoic Marine Revolution. This discovery illustrates the remarkable ability of echinoderms, through the process of evolutionary optimization, to form a lightweight, stiff and damage-tolerant skeleton, which serves as an inspiration for biomimetic materials.
Assuntos
Evolução Biológica , Equinodermos , Animais , Equinodermos/fisiologia , Estrelas-do-MarRESUMO
Human society is dependent on nature1,2, but whether our ecological foundations are at risk remains unknown in the absence of systematic monitoring of species' populations3. Knowledge of species fluctuations is particularly inadequate in the marine realm4. Here we assess the population trends of 1,057 common shallow reef species from multiple phyla at 1,636 sites around Australia over the past decade. Most populations decreased over this period, including many tropical fishes, temperate invertebrates (particularly echinoderms) and southwestern Australian macroalgae, whereas coral populations remained relatively stable. Population declines typically followed heatwave years, when local water temperatures were more than 0.5 °C above temperatures in 2008. Following heatwaves5,6, species abundances generally tended to decline near warm range edges, and increase near cool range edges. More than 30% of shallow invertebrate species in cool latitudes exhibited high extinction risk, with rapidly declining populations trapped by deep ocean barriers, preventing poleward retreat as temperatures rise. Greater conservation effort is needed to safeguard temperate marine ecosystems, which are disproportionately threatened and include species with deep evolutionary roots. Fundamental among such efforts, and broader societal needs to efficiently adapt to interacting anthropogenic and natural pressures, is greatly expanded monitoring of species' population trends7,8.
Assuntos
Antozoários , Recifes de Corais , Clima Quente Extremo , Peixes , Aquecimento Global , Invertebrados , Oceanos e Mares , Água do Mar , Alga Marinha , Animais , Austrália , Peixes/classificação , Invertebrados/classificação , Aquecimento Global/estatística & dados numéricos , Alga Marinha/classificação , Dinâmica Populacional , Densidade Demográfica , Água do Mar/análise , Extinção Biológica , Conservação dos Recursos Naturais/tendências , Equinodermos/classificaçãoRESUMO
Covering: January to December 2021This review covers the literature published in 2021 for marine natural products (MNPs), with 736 citations (724 for the period January to December 2021) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1425 in 416 papers for 2021), together with the relevant biological activities, source organisms and country of origin. Pertinent reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. An analysis of the number of authors, their affiliations, domestic and international collection locations, focus of MNP studies, citation metrics and journal choices is discussed.
Assuntos
Produtos Biológicos , Cnidários , Animais , Produtos Biológicos/química , Biologia Marinha , Estrutura Molecular , Cnidários/química , Equinodermos/química , Organismos AquáticosRESUMO
Gastropods of over a dozen genera in the family Eulimidae have been identified as parasites of brittle stars, and many more remain to be discovered and described for a comprehensive understanding of the evolutionary history of their host-parasite relationships. In this study, we describe Fusceulimoides kohtsukai gen. et sp. nov., parasitic on the little brittle star, Ophiactis savignyi (Ophiactidae), in Kanagawa, central Japan. The new genus is distinguished from other eulimid genera by the combination of following seven conchological characters: (1) a very small size of up to 1.7 mm high, (2) a colorless translucent appearance, (3) a conical pupiform shape with a paucispiral protoconch, (4) slightly convex teleoconch whorls, (5) a remarkably large body whorl occupying 65-70% of the total shell height, (6) a broad, somewhat squarish and laterally expanded aperture with a strongly curved outer lip, and (7) a developed parietal callus without an indentation or depression in the umbilical area. A multi-locus molecular phylogeny revealed its distant relationship to Hemiliostraca + Pyramidelloides, a previously known clade of ophiuroid parasites, thereby suggesting multiple origins of this host-parasite association in Eulimidae.
Assuntos
Gastrópodes , Parasitos , Animais , Japão , Equinodermos , FilogeniaRESUMO
The nervous system of the Asteroidea (starfish or seastar) consists of radial nerve cords (RNCs) that interconnect with a ring nerve. Despite its relative simplicity, it facilitates the movement of multiple arms and numerous tube feet, as well as regeneration of damaged limbs. Here, we investigated the RNC ultrastructure and its molecular components within the of Pacific crown-of-thorns starfish (COTS; Acanthaster sp.), a well-known coral predator that in high-density outbreaks has major ecological impacts on coral reefs. We describe the presence of an array of unique small bulbous bulbs (40-100 µm diameter) that project from the ectoneural region of the adult RNC. Each comprise large secretory-like cells and prominent cilia. In contrast, juvenile COTS and its congener Acanthaster brevispinus lack these features, both of which are non-corallivorous. Proteomic analysis of the RNC (and isolated neural bulbs) provides the first comprehensive echinoderm protein database for neural tissue, including numerous secreted proteins associated with signalling, transport and defence. The neural bulbs contained several neuropeptides (e.g., bombyxin-type, starfish myorelaxant peptide, secretogranin 7B2-like, Ap15a-like, and ApNp35) and Deleted in Malignant Brain Tumor 1-like proteins. In summary, this study provides a new insight into the novel traits of COTS, a major pest on coral reefs, and a proteomics resource that can be used to develop (bio)control strategies and understand molecular mechanisms of regeneration.
Assuntos
Distrofias de Cones e Bastonetes , Tecido Nervoso , Animais , Nervo Radial , Proteômica , Estrelas-do-Mar , EquinodermosRESUMO
As the climate continues to change, it is not just the magnitude of these changes that is important - equally critical is the timing of these events. Conditions that may be well tolerated at one time can become detrimental if experienced at another, as a result of seasonal acclimation. Temperature is the most critical variable as it affects most aspects of an organism's physiology. To address this, we quantified arm regeneration and respiration in the Australian brittle star Ophionereis schayeri for 10â weeks in response to a +3°C warming (18.5°C, simulating a winter heatwave) compared with ambient winter temperature (15.5°C). The metabolic scaling rate (b=0.635 at 15.5°C and 0.746 at 18.5°C) with respect to size was similar to that of other echinoderms and was not affected by temperature. Elevated temperature resulted in up to a 3-fold increase in respiration and a doubling of regeneration growth; however, mortality was greater (up to 44.2% at 18.5°C), especially in the regenerating brittle stars. Metabolic rate of the brittle stars held at 18.5°C was much higher than expected (Q10≈23) and similar to that of O. schayeri tested in summer, which was near their estimated thermotolerance limits. The additional costs associated with the elevated metabolism and regeneration rates incurred by the unseasonably warm winter temperatures may lead to increased mortality and predation risk.
Assuntos
Braço , Equinodermos , Animais , Estações do Ano , Austrália , Equinodermos/fisiologia , Temperatura , Aclimatação/fisiologia , Oceanos e MaresRESUMO
Microplastics are now polluting all seas and, while studies have found numerous negative interactions between plastic pollution and marine animals, the effects on embryonic development are poorly understood. A potentially important source of developmental ecotoxicity comes from chemicals leached from plastic particles to the marine environment. Here we investigate the effects of leachates from new and beach-collected pellets on the embryonic and larval development of the sea urchin Strongylocentrotus purpuratus and demonstrate that exposure of developing embryos to these leachates elicits severe, consistent and treatment-specific developmental abnormalities including radialisation of the embryo and malformation of the skeleton, neural and immune cells. Using a multi-omics approach we define the developmental pathways disturbed upon exposure to PVC leachates and provide a mechanistic view that pinpoints cellular redox stress and energy production as drivers of phenotypic abnormalities following exposure to PVC leachates. Analysis of leachates identified high concentrations of zinc that are the likely cause of these observed defects. Our findings point to clear and specific detrimental effects of marine plastic pollution on the development of echinoderms, demonstrating that chemicals leached from plastic particles into sea water can produce strong developmental abnormalities via specific pathways, and therefore have the potential to impact on a wide range of organisms.
Assuntos
Plásticos , Poluentes Químicos da Água , Animais , Plásticos/toxicidade , Plásticos/química , Ouriços-do-Mar , Equinodermos , Microplásticos , Desenvolvimento Embrionário , Poluentes Químicos da Água/análiseRESUMO
Isolation of bioactive products from the marine environment is considered a very promising approach to identify new compounds that can be used for further drug development. In this work we have isolated three new compounds from the purpuroine family by mass-guided preparative HPLC; purpuroine K-M. These compounds where screened for antibacterial- and antifungal activity, antibiofilm formation and anti-cell proliferation activity. Additionally, apoptosis-, cell cycle-, kinase binding- and docking studies were performed to evaluate the mechanism-of-action. None of the compounds showed activity in antibacterial-, antibiofilm- or antifungal assays. However, one of the isolated compounds, purpuroine K, showed activity against two cell lines, MV-4-11 and MOLM-13, two AML cell lines both carrying the FTL3-ITD mutation. In MV-4-11 cells, purpuroine K was found to increase apoptosis and arrest cells cycle in G1/G0, which is a common feature of FLT3 inhibitors. Interactions between purpuroine K and the FLT3 wild type or FLT3 ITD mutant proteins could however not be elucidated in our kinase binding and docking studies. In conclusion, we have isolated three novel molecules, purpuroine K-M, one of which (purpuroine K) shows a potent activity against FLT3-ITD mutated AML cell lines, however, the molecular target(s) of purpuroine K still need to be further investigated.
Assuntos
Leucemia Mieloide Aguda , Animais , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Equinodermos , Antifúngicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Linhagem Celular , Apoptose , Mutação , Tirosina Quinase 3 Semelhante a fms/genética , Linhagem Celular TumoralRESUMO
Chronic inflammation can extensively burden a healthcare system. Several synthetic anti-inflammatory drugs are currently available in clinical practice, but each has its own side effect profile. The planet is gifted with vast and diverse oceans, which provide a treasure of bioactive compounds, the chemical structures of which may provide valuable pharmaceutical agents. Marine organisms contain a variety of bioactive compounds, some of which have anti-inflammatory activity and have received considerable attention from the scientific community for the development of anti-inflammatory drugs. This review describes such bioactive compounds, as well as crude extracts (published during 2010-2022) from echinoderms: namely, sea cucumbers, sea urchins, and starfish. Moreover, we also include their chemical structures, evaluation models, and anti-inflammatory activities, including the molecular mechanism(s) of these compounds. This paper also highlights the potential applications of those marine-derived compounds in the pharmaceutical industry to develop leads for the clinical pipeline. In conclusion, this review can serve as a well-documented reference for the research progress on the development of potential anti-inflammatory drugs from echinoderms against various chronic inflammatory conditions.
Assuntos
Equinodermos , Pepinos-do-Mar , Animais , Ouriços-do-Mar , Estrelas-do-Mar , Anti-Inflamatórios/farmacologiaRESUMO
Injury to the central nervous system (CNS) results in permanent damage and lack of function in most vertebrate animals, due to their limited regenerative capacities. In contrast, echinoderms can fully regenerate their radial nerve cord (RNC) following transection, with little to no scarring. Investigators have associated the regenerative capacity of some organisms to the stress response and inflammation produced by the injury. Here, we explore the gene activation profile of the stressed holothurian CNS. To do this, we performed RNA sequencing on isolated RNC explants submitted to the stress of transection and enzyme dissection and compared them with explants kept in culture for 3 days following dissection. We describe stress-associated genes, including members of heat-shock families, ubiquitin-related pathways, transposons, and apoptosis that were differentially expressed. Surprisingly, the stress response does not induce apoptosis in this system. Other genes associated with stress in other animal models, such as hero proteins and those associated with the integrated stress response, were not found to be differentially expressed either. Our results provide a new viewpoint on the stress response in the nervous system of an organism with amazing regenerative capacities. This is the first step in deciphering the molecular processes that allow echinoderms to undergo fully functional CNS regeneration, and also provides a comparative view of the stress response in other organisms.
Assuntos
Traumatismos da Medula Espinal , Transcriptoma , Animais , Sistema Nervoso Central/fisiologia , Regeneração Nervosa/genética , Equinodermos , Perfilação da Expressão GênicaRESUMO
Echinoderms are marine water invertebrates that are represented by more than 7000 extant species, grouped in five classes and showing diverse morphologies (starfish, sea lilies, feather stars, sea urchins, sea cucumbers, brittle and basket stars). In an effort to further study their diversity, DNA barcodes (DNA fragments of the 5' end of the cytochrome c oxidase subunit I gene, COI) have been used to complement morphological examination in identifying evolutionary lineages. Although divergent clusters of COI sequences were reported to generally match morphological species delineations, they also revealed some discrepancies, suggesting overlooked species, ecophenotypic variation or multiple COI lineages within one species. Here, we sequenced COI fragments of 312 shallow-water echinoderms of the East Coast of South Africa (KwaZulu-Natal Province) and compared morphological identifications with species delimitations obtained with four methods that are exclusively based on COI sequences. We identified a total of 103 morphospecies including 18 that did not exactly match described species. We also report 46 COI sequences that showed large divergences (>5% p-distances) with those available to date and publish the first COI sequences for 30 species. Our analyses also identified discordances between morphological identifications and COI-based species delimitations for a considerable proportion of the morphospecies studied here (49/103). For most of them, further investigation is necessary to keep a sound connection between taxonomy and the growing importance of DNA-based research.
Assuntos
Código de Barras de DNA Taxonômico , Complexo IV da Cadeia de Transporte de Elétrons , Animais , Organismos Aquáticos , DNA/genética , Código de Barras de DNA Taxonômico/métodos , Equinodermos/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Filogenia , África do Sul , ÁguaRESUMO
Due to their low damage tolerance, engineering ceramic foams are often limited to non-structural usages. In this work, we report that stereom, a bioceramic cellular solid (relative density, 0.2-0.4) commonly found in the mineralized skeletal elements of echinoderms (e.g., sea urchin spines), achieves simultaneous high relative strength which approaches the Suquet bound and remarkable energy absorption capability (ca. 17.7 kJ kg-1) through its unique bicontinuous open-cell foam-like microstructure. The high strength is due to the ultra-low stress concentrations within the stereom during loading, resulted from their defect-free cellular morphologies with near-constant surface mean curvatures and negative Gaussian curvatures. Furthermore, the combination of bending-induced microfracture of branches and subsequent local jamming of fractured fragments facilitated by small throat openings in stereom leads to the progressive formation and growth of damage bands with significant microscopic densification of fragments, and consequently, contributes to stereom's exceptionally high damage tolerance.
Assuntos
Equinodermos , Ouriços-do-Mar , Animais , CerâmicaRESUMO
BACKGROUND: Here we release a new version of EchinoDB, EchinoDB v2.0 ( https://echinodb.uncc.edu ). EchinoDB is a database of genomic and transcriptomic data on echinoderms. The initial database consisted of groups of 749,397 orthologous and paralogous transcripts arranged in orthoclusters by sequence similarity. RESULTS: The updated version of EchinoDB includes two new major datasets: the RNA-Seq data of the brittle star Ophioderma brevispinum and the high-quality genomic assembly data of the green sea urchin Lytechinus variegatus. In addition, we enabled keyword searches for annotated data and installed an updated version of Sequenceserver to allow Basic Local Alignment Search Tool (BLAST) searches. The data are downloadable in FASTA format. The first version of EchinoDB appeared in 2016 and was implemented in GO on a local server. The new version has been updated using R Shiny to include new features and improvements in the application. Furthermore, EchinoDB now runs entirely in the cloud for increased reliability and scaling. CONCLUSION: EchinoDB serves a user base drawn from the fields of phylogenetics, developmental biology, genomics, physiology, neurobiology, and regeneration. As use cases, we illustrate the function of EchinoDB in retrieving components of signaling pathways involved in the tissue regeneration process of different echinoderms, including the emerging model species Ophioderma brevispinum. Moreover, we use EchinoDB to shed light on the conservation of the molecular components involved in two echinoderm-specific phenomena: spicule matrix proteins involved in the formation of stereom endoskeleton and the tensilin protein that contributes to the capacity of the connective tissues to quickly change its mechanical properties. The genes involved in the former had been previously studied in echinoids, while gene sequences involved in the latter had been previously described in holothuroids. Specifically, we ask (a) if the biomineralization-related proteins previously reported only in sea urchins are also present in other, non-echinoid, echinoderms and (b) if tensilin, the protein responsible for the control of stiffness of the mutable collagenous tissue, previously described in sea cucumbers, is conserved across the phylum.
