More than a simple epithelial layer: multifunctional role of echinoderm coelomic epithelium.

In echinoderms, the coelomic epithelium (CE) is reportedly the source of new circulating cells (coelomocytes) as well as the provider of molecular factors such as immunity-related molecules. However, its overall functions have been scarcely studied in detail. In this work, we used an integrated approach based on both microscopy (light and electron) and proteomic analyses to investigate the arm CE in the starfish Marthasterias glacialis during different physiological conditions (i.

Hexagonal Voronoi pattern detected in the microstructural design of the echinoid skeleton.

Repeated polygonal patterns are pervasive in natural forms and structures. These patterns provide inherent structural stability while optimizing strength-per-weight and minimizing construction costs. In echinoids (sea urchins), a visible regularity can be found in the endoskeleton, consisting of a lightweight and resistant micro-trabecular meshwork (stereom).

Flexible sutures reduce bending moments in shells: from the echinoid test to tessellated shell structures.

In the field of structural engineering, lightweight and resistant shell structures can be designed by efficiently integrating and optimizing form, structure and function to achieve the capability to sustain a variety of loading conditions with a reduced use of resources. Interestingly, a limitless variety of high-performance shell structures can be found in nature. Their study can lead to the acquisition of new functional solutions that can be employed to design innovative bioinspired constructions.

Constructional design of echinoid endoskeleton: main structural components and their potential for biomimetic applications.

The endoskeleton of echinoderms () is of mesodermal origin and consists of cells, organic components, as well as an inorganic mineral matrix. The echinoderm skeleton forms a complex lattice-system, which represents a model structure for naturally inspired engineering in terms of construction, mechanical behaviour and functional design. The sea urchin () endoskeleton consists of three main structural components: test, dental apparatus and accessory appendages.

Interactive effects between sinking polyethylene terephthalate (PET) microplastics deriving from water bottles and a benthic grazer.

The information concerning the toxicity of sinking microplastics (MPs) on benthic marine animals, particularly benthic grazers, is still scant. No study focused on biological weathering of sinked MPs operated by benthic organisms. This study aims at investigating the ingestion and the effects induced by 7-days dietary exposure to environmentally relevant amount (8, 80 and 800 particles/g of food) of irregular shaped and sized (diameter 12.

Extracellular matrix gene expression during arm regeneration in Amphiura filiformis.

Extracellular matrix (ECM) plays a dynamic role during tissue development and re-growth. Body part regeneration efficiency relies also on effective ECM remodelling and deposition. Among invertebrates, echinoderms are well known for their striking regenerative abilities since they can rapidly regenerate functioning complex structures.

Regeneration in Stellate Echinoderms: Crinoidea, Asteroidea and Ophiuroidea.

Reparative regeneration is defined as the replacement of lost adult body parts and is a phenomenon widespread yet highly variable among animals. This raises the question of which key cellular and molecular mechanisms have to be implemented in order to efficiently and correctly replace entire body parts in any animal. To address this question, different studies using an integrated cellular and functional genomic approach to study regeneration in stellate echinoderms (crinoids, asteroids and ophiuroids) had been carried out over the last few years.

Fundamental aspects of arm repair phase in two echinoderm models.

Regeneration is a post-embryonic developmental process that ensures complete morphological and functional restoration of lost body parts. The repair phase is a key step for the effectiveness of the subsequent regenerative process: in vertebrates, efficient re-epithelialisation, rapid inflammatory/immune response and post-injury tissue remodelling are fundamental aspects for the success of this phase, their impairment leading to an inhibition or total prevention of regeneration. Among deuterostomes, echinoderms display a unique combination of striking regenerative abilities and diversity of useful experimental models, although still largely unexplored.

An integrated view of asteroid regeneration: tissues, cells and molecules.

The potential for repairing and replacing cells, tissues, organs and body parts is considered a primitive attribute of life shared by all the organisms, even though it may be expressed to a different extent and which is essential for the survival of both individual and whole species. The ability to regenerate is particularly evident and widespread within invertebrates. In spite of the wide availability of experimental models, regeneration has been comprehensively explored in only a few animal systems (i.

Production, characterization and biocompatibility of marine collagen matrices from an alternative and sustainable source: the sea urchin Paracentrotus lividus.

Collagen has become a key-molecule in cell culture studies and in the tissue engineering field. Industrially, the principal sources of collagen are calf skin and bones which, however, could be associated to risks of serious disease transmission. In fact, collagen derived from alternative and riskless sources is required, and marine organisms are among the safest and recently exploited ones.

Echinoderm regeneration: an in vitro approach using the crinoid Antedon mediterranea.

Among echinoderms, crinoids are well known for their remarkable regenerative potential. Regeneration depends mainly on progenitor cells (undifferentiated or differentiated), which migrate and proliferate in the lesion site. The crucial role of the "progenitor" elements involved in the regenerative processes, in terms of cell recruitment, sources, and fate, is a central problem in view of its topical interest and biological implications.

Comparing dynamic connective tissue in echinoderms and sponges: morphological and mechanical aspects and environmental sensitivity.

Echinoderms and sponges share a unique feature that helps them face predators and other environmental pressures. They both possess collagenous tissues with adaptable viscoelastic properties. In terms of morphology these structures are typical connective tissues containing collagen fibrils, fibroblast- and fibroclast-like cells, as well as unusual components such as, in echinoderms, neurosecretory-like cells that receive motor innervation.

A dynamic model for predicting chemical concentrations in water and biota during the planning phase of aquatic ecotoxicological tests.

An unsteady-state fugacity model has been developed and validated as a predictive tool that will be useful in the planning phase of aquatic ecotoxicological tests. The model predicts the compound concentration trends in water and biota in experimental aquaria, with respect to the chemical and experimental conditions. The model has been validated with two echinoderm species, Paracentrotus lividus and Antedon mediterranea after a 28-days exposure to p,p'-DDE or triphenyltin chloride (TPT-Cl), respectively.

Endocrine disrupting compounds and echinoderms: new ecotoxicological sentinels for the marine ecosystem.

Echinoderms are valuable test species in marine ecotoxicology and offer a wide range of biological processes appropriate for this approach. In spite of this potential, available data in literature are still rather limited, particularly with regard to the possible effects of endocrine disrupter compounds (EDCs). This review presents echinoderms as useful models for ecotoxicological tests and gives a brief overview of the most significant results obtained in recent years, particularly in the context of the COMPRENDO EU project.

Novel, secondary sensory cell organ in ascidians: in search of the ancestor of the vertebrate lateral line.

A new mechanoreceptor organ, the "coronal organ," located in the oral siphon, is described by light and electron microscopy in the colonial ascidians Botryllus schlosseri and Botrylloides violaceus. It is composed of a line of sensory cells (hair cells), accompanied by supporting cells, that runs continuously along the margin of the velum and tentacles of the siphon. These hair cells resemble those of the vertebrate lateral line or, in general, the acoustico-lateralis system, because they bear a single cilium, located centrally or eccentrically to a hair bundle of numerous stereovilli.

Active supercontraction in rolling-up muscles of Glomeris marginata (myriapoda, diplopoda).

The lateroventral muscles of Glomeris marginata keep the animal rolled up and are able to develop and maintain great tension. Their fibers are not equipped with a particularly strong contractile apparatus but can super-contract. The sarcomere shortens its resting length by up 60% and in a typical supercontraction the thick filaments pass through the Z-line into adjacent sarcomeres.