scholarly journals Molecular insights into the powerful mucus-based adhesion of limpets ( Patella vulgata L.)

Open Biology ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 200019 ◽  
Author(s):  
Victor Kang ◽  
Birgit Lengerer ◽  
Ruddy Wattiez ◽  
Patrick Flammang

Limpets ( Patella vulgata L.) are renowned for their powerful attachments to rocks on wave-swept seashores. Unlike adult barnacles and mussels, limpets do not adhere permanently; instead, they repeatedly transition between long-term adhesion and locomotive adhesion depending on the tide. Recent studies on the adhesive secretions (bio-adhesives) of marine invertebrates have expanded our knowledge on the composition and function of temporary and permanent bio-adhesives. In comparison, our understanding of the limpets' transitory adhesion remains limited. In this study, we demonstrate that suction is not the primary attachment mechanism in P. vulgata ; rather, they secrete specialized pedal mucus for glue-like adhesion. Through combined transcriptomics and proteomics, we identified 171 protein sequences from the pedal mucus. Several of these proteins contain conserved domains found in temporary bio-adhesives from sea stars, sea urchins, marine flatworms and sea anemones. Many of these proteins share homology with fibrous gel-forming glycoproteins, including fibrillin, hemolectin and SCO-spondin. Moreover, proteins with potential protein- and glycan-degrading domains could have an immune defence role or assist degrading adhesive mucus to facilitate the transition from stationary to locomotive states. We also discovered glycosylation patterns unique to the pedal mucus, indicating that specific sugars may be involved in transitory adhesion. Our findings elucidate the mechanisms underlying P. vulgata adhesion and provide opportunities for future studies on bio-adhesives that form strong attachments and resist degradation until necessary for locomotion.

Marine Drugs ◽  
2021 ◽  
Vol 19 (12) ◽  
pp. 660
Author(s):  
Andrey B. Imbs ◽  
Ekaterina V. Ermolenko ◽  
Valeria P. Grigorchuk ◽  
Tatiana V. Sikorskaya ◽  
Peter V. Velansky

Marine invertebrates are a paraphyletic group that comprises more than 90% of all marine animal species. Lipids form the structural basis of cell membranes, are utilized as an energy reserve by all marine invertebrates, and are, therefore, considered important indicators of their ecology and biochemistry. The nutritional value of commercial invertebrates directly depends on their lipid composition. The lipid classes and fatty acids of marine invertebrates have been studied in detail, but data on their lipidomes (the profiles of all lipid molecules) remain very limited. To date, lipidomes or their parts are known only for a few species of mollusks, coral polyps, ascidians, jellyfish, sea anemones, sponges, sea stars, sea urchins, sea cucumbers, crabs, copepods, shrimp, and squid. This paper reviews various features of the lipid molecular species of these animals. The results of the application of the lipidomic approach in ecology, embryology, physiology, lipid biosynthesis, and in studies on the nutritional value of marine invertebrates are also discussed. The possible applications of lipidomics in the study of marine invertebrates are considered.


Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.


2019 ◽  
Vol 1 (1) ◽  
pp. 28-40 ◽  
Author(s):  
Zhiyi Lv ◽  
Qiongxuan Lu ◽  
Bo Dong

AbstractMorphogenesis is a process describing how the shapes of living tissues and bodies are created during development. Living and fossil organisms exhibit enormously diverse tissue architecture and body forms, although the functions of organs are evolutionally conserved. Current knowledge reveals that relatively conserved mechanisms are applied to control development among different species. However, the regulations of morphogenesis are quite diverse in detail. Animals in the ocean display a wide range of diversity of morphology suitable for their seawater environment. Nevertheless, compared with the intensive studies on terrestrial animals, research on marine animal morphogenesis is still insufficient. The increasing genomic data and the recently available gene editing methods, together with the fast development of imaging techniques, quantitative analyses and biophysical models, provide us the opportunities to have a deeper understanding of the principles that drive the diverse morphogenetic processes in marine animals. In this review, we summarize the recent studies of morphogenesis and evolution at molecular, cellular and tissue levels, with a focus on three model marine animals, namely ascidians, sea urchins and sea anemones.


Author(s):  
Heinz A. Lowenstam ◽  
Stephen Weiner

The Echinodermata are certainly one of the most unusual and interesting phyla from the biomineralization point of view. They all live in the marine environment. The five major taxonomic classes (Asteroidea or sea stars, Ophiuroidea or brittle stars, Echinoidea or sea urchins, Crinoidea or sea lilies, and Holothuroidea or sea cucumbers) have quite different anatomical shapes and are characterized by fivefold symmetry. Each group forms mineralized hard parts. In the Echinoidea the skeletal elements are fused together to form a rigid test, whereas in the Asteroidea, Ophiuroidea and Crinoidea the skeletal elements or ossicles are articulated with one another. In the Holothuroidea the skeleton is usually reduced to microscopic ossicles or spicules, and, in some cases, mineralized granules as well. The hard parts of echinoderms vary enormously in shape and function and include not only the diverse skeletal elements, but also spines and teeth. Remarkably, with very few exceptions, the mineralized hard parts are formed from the same mineral, magnesium-bearing calcite [usually 5–15% as magnesium carbonate (Chave 1952, 1954; Raup 1966)], which has some unique and interesting properties. The ultrastructure of many of the macroscopic skeletal hard parts has a characteristic spongy or fenestrate structure (called the stereom) and is riddled with labyrinthine cavities (collectively called the stereom space). In echinoid spines the stereom spaces are secondarily filled in to form areas of solid mineral. The surfaces of the mineral phase are very smooth, even when examined a high magnification in the SEM (Towe 1967; Millonig 1970). Furthermore, the broken surfaces show no characteristic ultrastructural motif, which is observed in almost all other mineralized tissues in which the individual crystals are enveloped by layers of organic material. The fracture surfaces of echinoderm calcite actually have a conchoidal cleavage (Towe 1967), which is characteristic of glassy or amorphous materials. It is, therefore, most surprising that when individual skeletal plates, spines, spicules, ossicles, and even whole teeth are examined in polarized light or by X-ray diffraction, they behave as if they are single crystals! (Towe 1967; Donnay and Pawon 1969).


2019 ◽  
Vol 374 (1784) ◽  
pp. 20190196 ◽  
Author(s):  
Martina Lachnit ◽  
Matthias T. Buhmann ◽  
Jennifer Klemm ◽  
Nils Kröger ◽  
Nicole Poulsen

Throughout all kingdoms of life, a large number of adhesive biomolecules have evolved to allow organisms to adhere to surfaces underwater. Proteins play an important role in the adhesion of numerous marine invertebrates (e.g. mussels, sea stars, sea urchins) whereas much less is known about the biological adhesives from marine plants, including the diatoms. Diatoms are unicellular microalgae that together with bacteria dominate marine biofilms in sunlit habitats. In this study we present the first proteomics analyses of the diatom adhesive material isolated from the tenacious fouling species Amphora coffeaeformis . We identified 21 proteins, of which 13 are diatom-specific. Ten of these proteins share a conserved C-terminal domain, termed GDPH domain, which is widespread yet not ubiquitously present in all diatom classes. Immunofluorescence localization of a GDPH domain bearing protein (Ac629) as well as two other proteins identified in this study (Ac1442, Ac9617) demonstrated that these are components of the adhesive trails that are secreted by cells that glide on surfaces. This article is part of the theme issue ‘Transdisciplinary approaches to the study of adhesion and adhesives in biological systems’.


Marine Drugs ◽  
2019 ◽  
Vol 17 (6) ◽  
pp. 352 ◽  
Author(s):  
Emily J. S. Claereboudt ◽  
Guillaume Caulier ◽  
Corentin Decroo ◽  
Emmanuel Colson ◽  
Pascal Gerbaux ◽  
...  

Echinoderms form a remarkable phylum of marine invertebrates that present specific chemical signatures unique in the animal kingdom. It is particularly the case for essential triterpenoids that evolved separately in each of the five echinoderm classes. Indeed, while most animals have Δ5-sterols, sea cucumbers (Holothuroidea) and sea stars (Asteroidea) also possess Δ7 and Δ9(11)-sterols, a characteristic not shared with brittle stars (Ophiuroidea), sea urchins (Echinoidea), and crinoids (Crinoidea). These particular Δ7 and Δ9(11) sterols emerged as a self-protection against membranolytic saponins that only sea cucumbers and sea stars produce as a defense mechanism. The diversity of saponins is large; several hundred molecules have been described in the two classes of these saponins (i.e., triterpenoid or steroid saponins). This review aims to highlight the diversity of triterpenoids in echinoderms by focusing on sterols and triterpenoid glycosides, but more importantly to provide an updated view of the biosynthesis of these molecules in echinoderms.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3122 ◽  
Author(s):  
Lisheng Zhang ◽  
Lingling Zhang ◽  
Dongtao Shi ◽  
Jing Wei ◽  
Yaqing Chang ◽  
...  

Increases in ocean temperature due to climate change are predicted to change the behaviors of marine invertebrates. Altered behaviors of keystone ecosystem engineers such as echinoderms will have consequences for the fitness of individuals, which are expected to flow on to the local ecosystem. Relatively few studies have investigated the behavioral responses of echinoderms to long-term elevated temperature. We investigated the effects of exposure to long-term (∼31 weeks) elevated temperature (∼3 °C above the ambient water temperature) on covering, sheltering and righting behaviors of the sea urchinStrongylocentrotus intermedius. Long-term elevated temperature showed different effects on the three behaviors. It significantly decreased covering behavior, including both covering behavior reaction (time to first covering) and ability (number of covered sea urchins and number of shells used for covering). Conversely, exposure to long-term elevated temperature significantly increased sheltering behavior. Righting response inS. intermediuswas not significantly different between temperature treatments. The results provide new information into behavioral responses of echinoderms to ocean warming.


2021 ◽  
pp. 1-11
Author(s):  
Danni Li ◽  
Lin Zhang ◽  
Nathaniel W. Nelson ◽  
Michelle M. Mielke ◽  
Fang Yu

Background: Utilities of blood-based biomarkers in Alzheimer’s disease (AD) clinical trials remain unknown. Objective: To evaluate the ability of plasma neurofilament light chain (NfL) to predict future declines in cognition and activities of daily living (ADL) outcomes in 26 older adults with mild-to-moderate AD dementia from the FIT-AD Trial. Methods: Plasma NfL was measured at baseline and 3 and 6 months. Cognition and ADL were assessed using the AD Assessment Scale-Cognition (ADAS-Cog) and AD Uniform Dataset Instruments and Disability Assessment for Dementia (DAD), respectively, at baseline, 3, 6, 9, and 12 months. Linear mixed effects models were used to examine the associations between baseline or change in plasma NfL and changes in outcomes. Results: Higher baseline plasma NfL was associated with greater rate of decline in ADAS-Cog from baseline to 6 months (standardized estimate of 0.00462, p = 0.02853) and in ADL from baseline to 12 months (standardized estimate of –0.00284, p = 0.03338). Greater increase in plasma NfL in short term from baseline to 3 months was associated with greater rate of decline in memory and ADL from 3 to 6 months (standardized estimate of –0.04638 [0.003], p = 0.01635; standardized estimate of –0.03818, p = 0.0435) and greater rate of decline in ADL from 3 to 12 month (standardized estimate of –0.01492, p = 0.01082). Conclusion: This study demonstrated that plasma NfL might have the potential to predict cognitive and function decline up to 12 months. However, future studies with bigger sample sizes need to confirm the findings.


Author(s):  
Robert Stojanov ◽  
Sarah Rosengaertner ◽  
Alex de Sherbinin ◽  
Raphael Nawrotzki

AbstractDevelopment cooperation actors have been addressing climate change as a cross-cutting issue and investing in climate adaptation projects since the early 2000s. More recently, as concern has risen about the potential impacts of climate variability and change on human mobility, development cooperation actors have begun to design projects that intentionally address the drivers of migration, including climate impacts on livelihoods. However, to date, we know little about the development cooperation’s role and function in responding to climate related mobility and migration. As such, the main aim of this paper is to outline the policy frameworks and approaches shaping development cooperation actors’ engagement and to identify areas for further exploration and investment. First, we frame the concept of climate mobility and migration and discuss some applicable policy frameworks that govern the issue from various perspectives; secondly, we review the toolbox of approaches that development cooperation actors bring to climate mobility; and third, we discuss the implications of the current Covid-19 pandemic and identify avenues for the way forward. We conclude that ensuring safe and orderly mobility and the decent reception and long-term inclusion of migrants and displaced persons under conditions of more severe climate hazards, and in the context of rising nationalism and xenophobia, poses significant challenges. Integrated approaches across multiple policy sectors and levels of governance are needed. In addition to resources, development cooperation actors can bring data to help empower the most affected communities and regions and leverage their convening power to foster more coordinated approaches within and across countries.


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