scholarly journals Triterpenoids in Echinoderms: Fundamental Differences in Diversity and Biosynthetic Pathways

Marine Drugs ◽  
2019 ◽  
Vol 17 (6) ◽  
pp. 352 ◽  
Author(s):  
Emily J. S. Claereboudt ◽  
Guillaume Caulier ◽  
Corentin Decroo ◽  
Emmanuel Colson ◽  
Pascal Gerbaux ◽  
...  
Keyword(s):  
Defense Mechanism ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Animal Kingdom ◽  
Sea Stars ◽  
Sea Cucumbers ◽  
Specific Chemical ◽  
Chemical Signatures ◽  
Triterpenoid Glycosides ◽  
Self Protection

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.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

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.

Echinodermata

2017 ◽  
Author(s):  
David V.P. Conway ◽  
Claudia Castellani ◽  
Eve C. Southward
Keyword(s):  
Life Cycle ◽  
Sea Urchins ◽  
Tree Of Life ◽  
Diverse Group ◽  
Sea Stars ◽  
Sea Cucumbers ◽  
Brittle Stars ◽  
General Morphology ◽  
Family Level ◽  
Feather Stars

This chapter describes the taxonomy of Echinodermata, a diverse group of organisms consisting systematically of five classes including sea stars (Asteroidea), brittle stars (Ophiuroidea), sea urchins (Echinoidea), sea cucumbers (Holothuroidea), and feather stars (Crinoidea). It covers their life cycle, ecology, and general morphology. It includes a section that indicates the systematic placement of the taxon described within the tree of life, and lists the key marine representative illustrated in the chapter (usually to genus or family level). This section also provides information on the taxonomic authorities responsible for the classification adopted, recent changes which might have occurred, and lists relevant taxonomic sources.

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
Keyword(s):  
Marine Invertebrates ◽  
Sea Urchins ◽  
Immune Defence ◽  
Sea Anemones ◽  
Sea Stars ◽  
Patella Vulgata ◽  
Future Studies ◽  
Attachment Mechanism ◽  
And Function

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.

scholarly journals Identification of proteins in the adhesive trails of the diatom Amphora coffeaeformis

2019 ◽  
Vol 374 (1784) ◽  
pp. 20190196 ◽  
Author(s):  
Martina Lachnit ◽  
Matthias T. Buhmann ◽  
Jennifer Klemm ◽  
Nils Kröger ◽  
Nicole Poulsen
Keyword(s):  
Marine Invertebrates ◽  
Sea Urchins ◽  
Biological Systems ◽  
Theme Issue ◽  
Sea Stars ◽  
Adhesive Material ◽  
Marine Plants ◽  
Terminal Domain ◽  
Marine Biofilms ◽  
Amphora Coffeaeformis

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’.

The sterols of echinoderms

1972 ◽  
Vol 180 (1059) ◽  
pp. 223-246 ◽  
Keyword(s):  
Phylogenetic Relationships ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Point Of View ◽  
Biological Origin ◽  
Sea Cucumbers ◽  
Biochemical Evidence ◽  
Modern Methods ◽  
Close Relationship ◽  
The One

The pioneering work of Bergmann and his colleagues demonstrated that marine invertebrates in many cases contain complex sterol mixtures consisting of C 27 , C 28 and C 29 sterols of varying degrees of unsaturation (Bergmann 1949, 1962). The sterols found in the phylum Echinodermata have proved of particular interest not only from the point of view of their composition and biological origin but also from phylogenetic considerations. Dorée (1909) first recognized that the sterol of a starfish differed from cholesterol, the typical sterol of higher animals. Later Kossel & Edlbacher (1915) obtained the sterol from a starfish, Asteropecten aurantiacus , and named it stellasterol. Subsequently Bergmann & Stansbury (1944) concluded that starfish sterols are mixtures which include stellastenol (1) and stellasterol, the 22, 23-dihydro derative of stellastenol (Shoppee 1964) Extending their studies Bergmann and co-workers demonstrated that the echinoderms can be divided into two groups on the basis of the types of sterol which they contain. Crinoidea (sea lilies), Ophiuroidea (brittle stars) and Echinoidea (sea urchins) contain sterols with a ∆ 5 bond while the Asteroidea (starfish) and Holothuroidea (sea cucumbers) contain mixtures in which sterols with a ∆ 7 bond predominate (Bergmann 1962). This division of echinoderms according to sterol type has recently been confirmed by Gupta & Scheuer (1968) using more modern methods of sterol analysis. Bergmann (1962) concluded that the distribution of ∆ 5 and ∆ 7 sterols in the different classes of echinoderms is a reflexion of the phylogenetic relationships which exist in the phylum. From embryological evidence there is a close relationship between the asteroids and holothuroids on the one hand and the ophiuroids and echinoids on the other (Bergmann 1962; Hyman 1955). In addition to the data on sterols other comparative biochemical evidence on the occurrence and distribution of batyl alcohol, spinochromes and phosphagens in echinoderms is in accord with these phylogenetic relationships (Singh, Moore & Scheuer 1967; Bolker 1967 α ). The validity of the embryological and biochemical evidence, however, has been contested by Fell who regards the asteroids to be more closely related to the ophiuroids while the holothuroids have some affinities with the echinoids (Fell 1948, 1963, 1965; Fell & Pawson 1966; Bolker 1967 α ).

scholarly journals Current Progress in Lipidomics of Marine Invertebrates

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
Keyword(s):  
Nutritional Value ◽  
Animal Species ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Basis ◽  
Marine Animal ◽  
Sea Anemones ◽  
Sea Stars ◽  
Lipid Molecular Species ◽  
Paraphyletic Group

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.

scholarly journals A newly discovered radiation of endoparasitic gastropods and their coevolution with asteroid hosts in Antarctica

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Kara K. S. Layton ◽  
Greg W. Rouse ◽  
Nerida G. Wilson
Keyword(s):  
Marine Invertebrates ◽  
Global Scale ◽  
Morphological Data ◽  
Sea Stars ◽  
Single Host ◽  
Scotia Arc ◽  
Event Based ◽  
Genus One ◽  
Future Work ◽  
The Antarctic

Abstract Background Marine invertebrates are abundant and diverse on the continental shelf in Antarctica, but little is known about their parasitic counterparts. Endoparasites are especially understudied because they often possess highly modified body plans that pose problems for their identification. Asterophila, a genus of endoparasitic gastropod in the family Eulimidae, forms cysts in the arms and central discs of asteroid sea stars. There are currently four known species in this genus, one of which has been described from the Antarctic Peninsula (A. perknasteri). This study employs molecular and morphological data to investigate the diversity of Asterophila in Antarctica and explore cophylogenetic patterns between host and parasite. Results A maximum-likelihood phylogeny of Asterophila and subsequent species-delimitation analysis uncovered nine well-supported putative species, eight of which are new to science. Most Asterophila species were found on a single host species, but four species were found on multiple hosts from one or two closely related genera, showing phylogenetic conservatism of host use. Both distance-based and event-based cophylogenetic analyses uncovered a strong signal of coevolution in this system, but most associations were explained by non-cospeciation events. Discussion The prevalence of duplication and host-switching events in Asterophila and its asteroid hosts suggests that synchronous evolution may be rare even in obligate endoparasitic systems. The apparent restricted distribution of Asterophila from around the Scotia Arc may be an artefact of concentrated sampling in the area and a low obvious prevalence of infection. Given the richness of parasites on a global scale, their role in promoting host diversification, and the threat of their loss through coextinction, future work should continue to investigate parasite diversity and coevolution in vulnerable ecosystems.

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