scholarly journals Sea Urchins as an Inspiration for Robotic Designs

2018 ◽  
Vol 6 (4) ◽  
pp. 112 ◽  
Author(s):  
Klaus Stiefel ◽  
Glyn Barrett
Keyword(s):  
Nervous System ◽  
Sea Urchin ◽  
Sea Urchins ◽  
Design Principles ◽  
Machine Design ◽  
Neuromorphic Engineering ◽  
Motor Systems ◽  
Future Directions ◽  
Intelligent Machine ◽  
Tube Feet

Neuromorphic engineering is the approach to intelligent machine design inspired by nature. Here, we outline possible robotic design principles derived from the neural and motor systems of sea urchins (Echinoida). Firstly, we review the neurobiology and locomotor systems of sea urchins, with a comparative emphasis on differences to animals with a more centralized nervous system. We discuss the functioning and enervation of the tube feet, pedicellariae, and spines, including the limited autonomy of these structures. We outline the design principles behind the sea urchin nervous system. We discuss the current approaches of adapting these principles to robotics, such as sucker-like structures inspired by tube feet and a robotic adaptation of the sea urchin jaw, as well as future directions and possible limitations to using these principles in robots.

scholarly journals Interspecific Analysis of Sea Urchin Adhesive Composition Emphasizes Variability of Glycans Conjugated With Putative Adhesive Proteins

2021 ◽  
Vol 8 ◽  
Author(s):  
Lisa Gaspar ◽  
Patrick Flammang ◽  
Ricardo José ◽  
Ricardo Luis ◽  
Patrício Ramalhosa ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Sea Urchins ◽  
Secretory Granules ◽  
Paracentrotus Lividus ◽  
Single Species ◽  
Lectin Histochemistry ◽  
Additional Species ◽  
Adhesive Organs ◽  
Adhesive Proteins ◽  
Tube Feet

Sea urchins possess specialized adhesive organs, tube feet. Although initially believed to function as suckers, it is currently accepted that they rely on adhesive and de-adhesive secretions to attach and detach repeatedly from the substrate. Given the biotechnological potential of their strong reversible adhesive, sea urchins are under investigation to identify the protein and glycan molecules responsible for its surface coupling, cohesion and polymerization properties. However, this characterization has only focused on a single species, Paracentrotus lividus. To provide a broader insight into sea urchins adhesion, a comparative study was performed using four species belonging to different taxa and habitats: Diadema africanum, Arbacia lixula, Paracentrotus lividus and Sphaerechinus granularis. Their tube feet external morphology and histology was studied, together with the ultrastructure of their adhesive secretory granules. In addition, one antibody and five lectins were used on tube foot histological sections and extracts, and on adhesive footprints to detect the presence of adhesion-related (glyco)proteins like those present in P. lividus in other species. Results confirmed that the antibody raised against P. lividus Nectin labels the adhesive organs and footprints in all species. This result was further confirmed by a bioinformatic analysis of Nectin-like sequences in ten additional species, increasing the comparison to seven families and three orders. The five tested lectins (GSL II, WGA, STL, LEL, and SBA) demonstrated that there is high interspecific variability of the glycans involved in sea urchin adhesion. However, there seems to be more conservation among taxonomically closer species, like P. lividus and S. granularis. In these species, lectin histochemistry and lectin blots indicated the presence of high molecular weight putative adhesive glycoproteins bearing N-acetylglucosamine residues in the form of chitobiose in the adhesive epidermis and footprints. Our results emphasize a high selective pressure for conservation of functional domains in large putative cohesive proteins and highlight the importance of glycosylation in sea urchin adhesion with indications of taxonomy-related conservation of the conjugated glycans.

scholarly journals Characterization of the glycans involved in sea urchin Paracentrotus lividus reversible adhesion

2020 ◽  
Vol 167 (9) ◽  
Author(s):  
Mariana Simão ◽  
Mariana Moço ◽  
Luís Marques ◽  
Romana Santos
Keyword(s):  
Sea Urchin ◽  
Sea Urchins ◽  
Paracentrotus Lividus ◽  
Reversible Adhesion ◽  
The Subject ◽  
Complementary Techniques ◽  
Adhesive Organs ◽  
Tube Feet ◽  
Glycosidic Fraction

Abstract Sea urchins have hundreds of specialized adhesive organs, the tube feet, which play a key role in locomotion, substrate attachment and food capture. Tube feet are composed by two functional units: a proximal cylindrical stem that is mobile and flexible, attached to a distal flattened disc that produces adhesive secretions. Oral tube feet discs possess a specialized duo-glandular epidermis that produces adhesive and de-adhesive secretions, enabling strong but reversible adhesion to the substrate. Due to the growing interest in biomimetic adhesives, several studies have been carried out to characterize sea urchin adhesives, and up to date, it has been shown that it is composed by proteins and glycans. The protein fraction has been the subject of several studies, that pin-pointed several adhesion-related candidates. Contrastingly, little is known about the glycans that compose sea urchin adhesives. This study aims at contributing to this topic by focusing on the characterization of the glycosidic fraction of the adhesive secreted by the sea urchin Paracentrotus lividus (Lamarck, 1816), using a battery of 22 lectins, applied to 3 complementary techniques. Our results show that five lectins label exclusively the disc adhesive epidermis and simultaneously the secreted adhesive, being, therefore, most likely relevant for sea urchin adhesion. In addition, it was possible to determine that the glycosidic fraction of the adhesive is composed by a high molecular weight glycoprotein containing N-acetylglucosamine oligomers.

scholarly journals Tool Use by Four Species of Indo-Pacific Sea Urchins

2019 ◽  
Vol 7 (3) ◽  
pp. 69
Author(s):  
Glyn Barrett ◽  
Dominic Revell ◽  
Lucy Harding ◽  
Ian Mills ◽  
Axelle Jorcin ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Tool Use ◽  
Plant Material ◽  
Transport Mechanism ◽  
Sea Urchins ◽  
Coral Rubble ◽  
Protection Mechanism ◽  
Covering Material ◽  
Tripneustes Gratilla ◽  
Tube Feet

We compared the covering behavior of four sea urchin species, Tripneustes gratilla, Pseudoboletia maculata, Toxopneustes pileolus, and Salmacis sphaeroides found in the waters of Malapascua Island, Cebu Province and Bolinao, Panagsinan Province, Philippines. Specifically, we measured the amount and type of covering material on each sea urchin, and in several cases, the recovery of debris material after stripping the animal of its cover. We found that Tripneustes gratilla and Salmacis sphaeroides have a higher affinity for plant material, especially seagrass, compared to Pseudoboletia maculata and Toxopneustes pileolus, which prefer to cover themselves with coral rubble and other calcified material. Only in Toxopneustes pileolus did we find a significant corresponding depth-dependent decrease in total cover area, confirming previous work that covering behavior serves as a protection mechanism against UV radiation. We found no dependence of particle size on either species or size of sea urchin, but we observed that larger sea urchins generally carried more and heavier debris. We observed a transport mechanism of debris onto the echinoid body surface utilizing a combination of tube feet and spines. We compare our results to previous studies, comment on the phylogeny of sea urchin covering behavior, and discuss the interpretation of this behavior as animal tool use.

scholarly journals Substituting mouse transcription factor Pou4f2 with a sea urchin orthologue restores retinal ganglion cell development

2016 ◽  
Vol 283 (1826) ◽  
pp. 20152978 ◽  
Author(s):  
Chai-An Mao ◽  
Cavit Agca ◽  
Julie A. Mocko-Strand ◽  
Jing Wang ◽  
Esther Ullrich-Lüter ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Sea Urchin ◽  
Ganglion Cells ◽  
Sea Urchins ◽  
Photoreceptor Cells ◽  
Retinal Ganglion ◽  
Mammalian Retina ◽  
Morphological Differences ◽  
And Function ◽  
Tube Feet

Pou domain transcription factor Pou4f2 is essential for the development of retinal ganglion cells (RGCs) in the vertebrate retina. A distant orthologue of Pou4f2 exists in the genome of the sea urchin (class Echinoidea) Strongylocentrotus purpuratus ( SpPou4f1/2 ), yet the photosensory structure of sea urchins is strikingly different from that of the mammalian retina. Sea urchins have no obvious eyes, but have photoreceptors clustered around their tube feet disc. The mechanisms that are associated with the development and function of photoreception in sea urchins are largely unexplored. As an initial approach to better understand the sea urchin photosensory structure and relate it to the mammalian retina, we asked whether SpPou4f1/2 could support RGC development in the absence of Pou4f2 . To answer this question, we replaced genomic Pou4f2 with an SpPou4f1/2 cDNA. In Pou4f2 -null mice, retinas expressing SpPou4f1/2 were outwardly identical to those of wild-type mice. SpPou4f1/2 retinas exhibited dark-adapted electroretinogram scotopic threshold responses, indicating functionally active RGCs. During retinal development, SpPou4f1/2 activated RGC-specific genes and in S. purpuratus , SpPou4f2 was expressed in photoreceptor cells of tube feet in a pattern distinct from Opsin4 and Pax6. Our results suggest that SpPou4f1/2 and Pou4f2 share conserved components of a gene network for photosensory development and they maintain their conserved intrinsic functions despite vast morphological differences in mouse and sea urchin photosensory structures.

scholarly journals Perception of Dissolved Food-Related Compounds by the Sea Urchin Paracentrotus lividus (Echinodermata: Echinoidea)

2021 ◽  
Vol 8 ◽  
Author(s):  
Orlando J. Luis ◽  
João M. Gago
Keyword(s):  
Sea Urchin ◽  
Sea Urchins ◽  
Wheat Gluten ◽  
Bovine Milk ◽  
Paracentrotus Lividus ◽  
Marine Species ◽  
Response Analysis ◽  
Specific Chemical ◽  
Related Compounds ◽  
Tube Feet

Echinoid feeding biology is well known but their sluggish responses to chemical stimuli have turned them into inadequately worked in the field of chemoreception. Echinoid responses to chemical stimulation had allowed, so far, only qualitative analyses based on tube-feet activity, directional, or masticatory movements, and artificial agarose foods. Besides stimulation through plumes of dissolved organic compounds and response analysis based on tube-feet activity, we propose another method to chemically stimulate echinoids that allows for fast and unambiguous responses and thus, quantitative analyses. Small squared pieces of absorbent semi-synthetic cleaning cloths, soaked with specific chemical compounds (simulacra), such as water insoluble lipid oils, were deposited singly or concurrently with a blank on the aboral hemisphere of each sea urchin, allowing choice and eventual transport down to the mouth by tube feet and spines of one or both cloths. The responsiveness of Paracentrotus lividus was clearly dependent on its nutritional state. Well-fed sea urchins (maize whole grains) rarely responded, while the ones fed with less caloric rations (Kombu seaweed) responded faster and objectively. Stimulating sea urchin P. lividus with 41 different food-related compounds, such as carbohydrates, proteins, peptides and amino acids, oils and fatty acids, and purified chemicals related with some human basic tastes, it was possible to evidence a clear ability of this echinoid species to positively discriminate proteins, starches, and a very few oils. Perceived as incitants/stimulants we have only found among proteins gliadin (from wheat gluten) but not casein (from bovine milk), among polysaccharides starch but not laminarin (from kelp) or glycogen (from mussels), and among lipids only the fatty acid linolenic acid. Among tissues, Kombu alga flesh and mussel flesh were readily perceived as both incitant/stimulant but not Kombu and mussel extracts. Therefore, the combined results reported here provide evidence for P. lividus as an omnivorous species rather than a strictly herbivorous marine species. However, the restricted group of food-related compounds perceived by this species as incitants or suppressants and as stimulants or deterrents was shown to be remarkably related to other vertebrates whose kinship was confirmed by the sequencing of the genome of another plant-eater sea urchin.

scholarly journals Adhesive plasticity among populations of purple sea urchin (Strongylocentrotus purpuratus)

2020 ◽  
Vol 223 (15) ◽  
pp. jeb228544
Author(s):  
Alyssa Y. Stark ◽  
Carla A. Narvaez ◽  
Michael P. Russell
Keyword(s):  
Sea Urchin ◽  
Sea Urchins ◽  
Strongylocentrotus Purpuratus ◽  
Population Level ◽  
Adhesive System ◽  
Adhesive Force ◽  
Artificial Substrates ◽  
Wave Forces ◽  
Skeletal Morphology ◽  
Tube Feet

ABSTRACTSea urchins native to the nearshore open coast experience periods of high, repeated wave forces that can result in dislodgement. To remain attached while clinging and locomoting across rocky substrates, sea urchins use adhesive tube feet. Purple sea urchins (Strongylocentrotus purpuratus) adhere to a variety of rock substrates (e.g. sandstone, mudstone, granite), and display morphological plasticity (skeletal morphology) to native substrate. We tested the hypothesis that their adhesive system is also plastic and varies as a function of native population and substrate. The results of our study support our hypothesis. Sea urchins from sandstone adhere less strongly to most substrates than those native to mudstone and granite rock. Sandstone produced the lowest whole animal adhesive force values across all populations, suggesting that this rock type is particularly challenging for sea urchins to adhere to. The number of adhesive tube feet that failed during experimental trials and the area used by sea urchins to attach, matches closely with whole animal adhesive force values: higher forces resulted in more tube foot failure and larger attachment area. On artificial substrates (glass and Plexiglass), differences in adhesion among populations was consistent with differences in adhesion on rock substrates except on glass, where sea urchins native to sandstone adhered more strongly to glass than any other substrate tested. To our knowledge, this study is the first to describe population-level plasticity in a biological adhesive system related to native substrate, and has significant implications for sea urchin ecology, behavior and functional morphology.

scholarly journals An overview of travel-associated central nervous system infectious diseases: risk assessment, general considerations and future directions

2014 ◽  
Vol 4 (8) ◽  
pp. 589-596
Author(s):  
Morteza Izadi ◽  
Arman Is'haqi ◽  
Mohammad Ali Is'haqi ◽  
Nematollah Jonaidi Jafari ◽  
Fatemeh Rahamaty ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Central Nervous System ◽  
Nervous System ◽  
Infectious Diseases ◽  
Future Directions

scholarly journals Design Principles: Literature Review, Analysis, and Future Directions

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Katherine K. Fu ◽  
Maria C. Yang ◽  
Kristin L. Wood
Keyword(s):  
Design Science ◽  
Design Principles ◽  
Grand Challenge ◽  
Formal Approach ◽  
Design Problems ◽  
Future Directions ◽  
Future Design ◽  
The Future ◽  
Tools And Techniques ◽  
Archival Practices

Design principles are created to codify and formalize design knowledge so that innovative, archival practices may be communicated and used to advance design science and solve future design problems, especially the pinnacle, wicked, and grand-challenge problems that face the world and cross-cutting markets. Principles are part of a family of knowledge explication, which also include guidelines, heuristics, rules of thumb, and strategic constructs. Definitions of a range of explications are explored from a number of seminal papers. Based on this analysis, the authors pose formalized definitions for the three most prevalent terms in the literature—principles, guidelines, and heuristics—and draw more definitive distinctions between the terms. Current research methods and practices with design principles are categorized and characterized. We further explore research methodologies, validation approaches, semantic principle composition through computational analysis, and a proposed formal approach to articulating principles. In analyzing the methodology for discovering, deriving, formulating, and validating design principles, the goal is to understand and advance the theoretical basis of design, the foundations of new tools and techniques, and the complex systems of the future. Suggestions for the future of design principles research methodology for added rigor and repeatability are proposed.

Evidence for Association of Vibrio Echinoideorum with Tissue Necrosis on Body Shell of the Green Sea Urchin Strongylocentrotus Droebachiensis

2021 ◽  
Author(s):  
Jonathan Hira ◽  
Klara Stensvåg
Keyword(s):  
Sea Urchin ◽  
Virulence Genes ◽  
Vibrio Vulnificus ◽  
Sea Urchins ◽  
Opportunistic Pathogen ◽  
Significant Degree ◽  
Strongylocentrotus Droebachiensis ◽  
Host Immune System ◽  
Progressive Development ◽  
Green Sea Urchin

Abstract “Sea urchin lesion syndrome” is known as sea urchins disease with the progressive development of necrotic epidermal tissue and loss of external organs, including appendages on the outer body surface. Recently, a novel strain, Vibrio echinoideorum has been isolated from the lesions of green sea urchin (Strongylocentrotus droebachiensis), an economically important mariculture species in Norway. V. echinoideorum has not been reported elsewhere in association of with green sea urchin lesion syndrome. Therefore, in this study, an immersion based bacterial challenge experiment was performed to expose sea urchins (wounded and non-wounded) to V. echinoideorum, thereby mimicking a nearly natural host-pathogen interaction under controlled conditions. This infection experiment demonstrated that only the injured sea urchins developed the lesion to a significant degree when exposed to V. echinoideorum. Pure cultures of the employed bacterial strain was recovered from the infected animals and its identity was confirmed by the MALDI-TOF MS spectra profiling. Additionally, the hemolytic phenotype of V. echinoideorum substantiated its virulence potential towards the host, and this was also supported by the cytolytic effect on red spherule cells of sea urchins. Furthermore, the genome sequence of V. echinoideorum was assumed to encode potential virulence genes and were subjected for in silico comparison with the established virulence factors of Vibrio vulnificus and Vibrio tasmaniensis. This comparative virulence profile provided novel insights about virulence genes and their putative functions related to chemotaxis, adherence, invasion, evasion of the host immune system, and damage of host tissue and cells. Thus, it supports the pathogenicity of V. echinoideorum. In conclusion, the interaction of V. echinoideorum with injured sea urchins appears to be essential for the development of lesion syndrome and therefore, revealing its potentiality as an opportunistic pathogen.

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