scholarly journals The unique skeleton of siliceous sponges (Porifera; Hexactinellida and Demospongiae) that evolved first from the Urmetazoa during the Proterozoic: a review

2007 ◽  
Vol 4 (1) ◽  
pp. 385-416 ◽  
Author(s):  
W. E. G. Müller ◽  
J. Li ◽  
H. C. Schröder ◽  
L. Qiao ◽  
X. Wang
Keyword(s):  
Sustainable Use ◽  
The Body ◽  
Inorganic Materials ◽  
Model Organisms ◽  
Sponge Cell ◽  
Axial Filament ◽  
Suberites Domuncula ◽  
Surface Receptors ◽  
Axial Canal ◽  
Siliceous Sponges

Abstract. Sponges (phylum Porifera) had been considered as an enigmatic phylum, prior to the analysis of their genetic repertoire/tool kit. Already with the isolation of the first adhesion molecule, galectin, it became clear that the sequences of the sponge cell surface receptors and those of the molecules forming the intracellular signal transduction pathways, triggered by them, share high similarity to those identified in other metazoan phyla. These studies demonstrated that all metazoan phyla, including the Porifera, originate from one common ancestor, the Urmetazoa. The sponges evolved during a time prior to the Ediacaran-Cambrian boundary (542 million years ago (myr)). They appeared during two major "snowball earth events", the Sturtian glaciation (710 to 680 myr) and the Varanger-Marinoan ice ages (605 to 585 myr). During this period the aqueous milieu was silica rich due to the silicate weathering. The oldest sponge fossils (Hexactinellida) have been described from Australia, China and Mongolia and were assessed to have existed coeval with the diverse Ediacara fauna. Only little younger are the fossils discovered in the Sansha section in Hunan (Early Cambrian; China). It has been proposed that only the sponges had the genetic repertoire to cope with the adverse conditions, e.g. temperature-protection molecules or proteins protecting them against ultraviolet radiation. The skeletal elements of the Hexactinellida (model organisms Monorhaphis chuni and Monorhaphis intermedia or Hyalonema sieboldi) and Demospongiae (models Suberites domuncula and Geodia cydonium), the spicules, are formed enzymatically by the anabolic enzyme silicatein and the catabolic enzyme silicase. Both, the spicules of Hexactinellida and of Demospongiae, comprise a central axial canal and an axial filament which harbors the silicatein. After intracellular formation of the first lamella around the channel and the subsequent extracellular apposition of further lamellae the spicules are completed in a net formed of collagen fibers. The data summarized here substantiate that with the finding of silicatein a new aera in the field of bio/inorganic chemistry started. For the first time strategies could be formulated and experimentally proven that allow the formation/synthesis of inorganic structures by organic molecules. These findings are not only of importance for the further understanding of basic pathways in the body plan formation of sponges but also of eminent importance for applied/commercial processes in a sustainable use of biomolecules for novel bio/inorganic materials.

scholarly journals The unique skeleton of siliceous sponges (Porifera; Hexactinellida and Demospongiae) that evolved first from the Urmetazoa during the Proterozoic: a review

2007 ◽  
Vol 4 (2) ◽  
pp. 219-232 ◽  
Author(s):  
W. E. G. Müller ◽  
H. C. Schröder ◽  
◽  
◽  
Keyword(s):  
Sustainable Use ◽  
The Body ◽  
Inorganic Materials ◽  
Model Organisms ◽  
Sponge Cell ◽  
Axial Filament ◽  
Suberites Domuncula ◽  
Surface Receptors ◽  
Axial Canal ◽  
Siliceous Sponges

Abstract. Sponges (phylum Porifera) had been considered as an enigmatic phylum, prior to the analysis of their genetic repertoire/tool kit. Already with the isolation of the first adhesion molecule, galectin, it became clear that the sequences of sponge cell surface receptors and of molecules forming the intracellular signal transduction pathways triggered by them, share high similarity with those identified in other metazoan phyla. These studies demonstrated that all metazoan phyla, including Porifera, originate from one common ancestor, the Urmetazoa. The sponges evolved prior to the Ediacaran-Cambrian boundary (542 million years ago [myr]) during two major "snowball earth events", the Sturtian glaciation (710 to 680 myr) and the Varanger-Marinoan ice ages (605 to 585 myr). During this period the ocean was richer in silica due to the silicate weathering. The oldest sponge fossils (Hexactinellida) have been described from Australia, China and Mongolia and are thought to have existed coeval with the diverse Ediacara fauna. Only little younger are the fossils discovered in the Sansha section in Hunan (Early Cambrian; China). It has been proposed that only the sponges possessed the genetic repertoire to cope with the adverse conditions, e.g. temperature-protection molecules or proteins protecting them against ultraviolet radiation. The skeletal elements of the Hexactinellida (model organisms Monorhaphis chuni and Monorhaphis intermedia or Hyalonema sieboldi) and Demospongiae (models Suberites domuncula and Geodia cydonium), the spicules, are formed enzymatically by the anabolic enzyme silicatein and the catabolic enzyme silicase. Both, the spicules of Hexactinellida and of Demospongiae, comprise a central axial canal and an axial filament which harbors the silicatein. After intracellular formation of the first lamella around the channel and the subsequent extracellular apposition of further lamellae the spicules are completed in a net formed of collagen fibers. The data summarized here substantiate that with the finding of silicatein a new aera in the field of bio/inorganic chemistry started. For the first time strategies could be formulated and experimentally proven that allow the formation/synthesis of inorganic structures by organic molecules. These findings are not only of importance for the further understanding of basic pathways in the body plan formation of sponges but also of eminent importance for applied/commercial processes in a sustainable use of biomolecules for novel bio/inorganic materials.

scholarly journals Insulin’s Discovery: New Insights on Its Hundredth Birthday: From Insulin Action and Clearance to Sweet Networks

2021 ◽  
Vol 22 (3) ◽  
pp. 1030
Author(s):  
Melanie Leroux ◽  
Martial Boutchueng-Djidjou ◽  
Robert Faure
Keyword(s):  
Type 1 Diabetes ◽  
Cell Surface ◽  
20Th Century ◽  
Insulin Action ◽  
100Th Anniversary ◽  
The Body ◽  
Nobel Lecture ◽  
Surface Receptors ◽  
The Third

In 2021, the 100th anniversary of the isolation of insulin and the rescue of a child with type 1 diabetes from death will be marked. In this review, we highlight advances since the ingenious work of the four discoverers, Frederick Grant Banting, John James Rickard Macleod, James Bertram Collip and Charles Herbert Best. Macleoad closed his Nobel Lecture speech by raising the question of the mechanism of insulin action in the body. This challenge attracted many investigators, and the question remained unanswered until the third part of the 20th century. We summarize what has been learned, from the discovery of cell surface receptors, insulin action, and clearance, to network and precision medicine.

The physical basis of mollusk shell chiral coiling

2021 ◽  
Vol 118 (48) ◽  
pp. e2109210118
Author(s):  
Régis Chirat ◽  
Alain Goriely ◽  
Derek E. Moulton
Keyword(s):  
Mathematical Model ◽  
The Body ◽  
Symmetric Body ◽  
Model Organisms ◽  
Physical Interaction ◽  
Mechanical Forces ◽  
Hard Shell ◽  
Left Right Asymmetry ◽  
Development And Evolution ◽  
Mollusk Shell

Snails are model organisms for studying the genetic, molecular, and developmental bases of left–right asymmetry in Bilateria. However, the development of their typical helicospiral shell, present for the last 540 million years in environments as different as the abyss or our gardens, remains poorly understood. Conversely, ammonites typically have a bilaterally symmetric, planispiraly coiled shell, with only 1% of 3,000 genera displaying either a helicospiral or a meandering asymmetric shell. A comparative analysis suggests that the development of chiral shells in these mollusks is different and that, unlike snails, ammonites with asymmetric shells probably had a bilaterally symmetric body diagnostic of cephalopods. We propose a mathematical model for the growth of shells, taking into account the physical interaction during development between the soft mollusk body and its hard shell. Our model shows that a growth mismatch between the secreted shell tube and a bilaterally symmetric body in ammonites can generate mechanical forces that are balanced by a twist of the body, breaking shell symmetry. In gastropods, where a twist is intrinsic to the body, the same model predicts that helicospiral shells are the most likely shell forms. Our model explains a large diversity of forms and shows that, although molluscan shells are incrementally secreted at their opening, the path followed by the shell edge and the resulting form are partly governed by the mechanics of the body inside the shell, a perspective that explains many aspects of their development and evolution.

scholarly journals Transcriptional regulation in model organisms: recent progress and clinical implications

Open Biology ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 190183 ◽  
Author(s):  
Jiaqi Tang ◽  
Zhenhua Xu ◽  
Lianfang Huang ◽  
Hui Luo ◽  
Xiao Zhu
Keyword(s):  
Transcriptional Regulation ◽  
Molecular Mechanisms ◽  
The Body ◽  
Model Organisms ◽  
Clinical Implications ◽  
Regulation Mechanism ◽  
Biological Behaviour ◽  
E Coli ◽  
Different Types

In this review, we will summarize model organisms used by scientists in the laboratory, including Escherichia coli , yeast, Arabidopsis thaliana , nematodes, Drosophila , zebrafish, mice and other animals. We focus on the progress in research exploring different types of E. coli in the human body, and the specific molecular mechanisms by which they play a role in humans. First, we discuss the specific transcriptional regulation mechanism of E. coli in cell development, maturation, ageing and longevity, as well as tumorigenesis and development. Then, we discuss how the synthesis of some important substances in cells is regulated and how this affects biological behaviour. Understanding and applying these mechanisms, presumably, can greatly improve the quality of people's lives as well as increase their lifespan. For example, some E. coli can activate certain cells by secreting insulin-like growth factor-1, thus activating the inflammatory response of the body, while other E. coli can inactivate the immune response of the body by secreting toxic factors.

scholarly journals Traditional Medicine Analysis and Sustainable Use of Korean Pond Wetland Plants in the Agricultural Landscape

2020 ◽  
Vol 12 (15) ◽  
pp. 5963
Author(s):  
Jinkwan Son ◽  
Changhyun Kim ◽  
Minjung Park ◽  
Dukkyu Choi ◽  
Sung-Wook Yun
Keyword(s):  
Small Intestine ◽  
Traditional Medicine ◽  
Agricultural Landscape ◽  
Sustainable Use ◽  
The Body ◽  
Educational Materials ◽  
Disease Treatment ◽  
Rural Villages ◽  
Use Patterns ◽  
Medicine Analysis

This study surveyed the most commonly observed plants at 40 pond wetlands in rural villages in Korea and assessed their use patterns in traditional medicine (TM) with reference to the contents of the Korea Traditional Knowledge Portal (KTKP). In this survey, 457 taxa in 108 families were identified. For these, there are use patterns in TM for 314 taxa; overall, 68.8% of the surveyed plants have uses in TM. The 314 taxa that have applications in TM involve 596 types of disease treatment and 771 types of efficacy. On average, for each taxon, there are 4.0 types of efficacy and 6.6 types of disease treatment. TM from 210 taxa have been described as applied to organs in 10 regions of the body: liver 123, lung 82, spleen 57, stomach 57, heart 45, large intestine 43, kidney 40, bladder 23, small intestine 16, and gall bladder 8. The results of this study will help support the conservation of pond wetlands that provide national biodiversity and various ecosystem services, by increasing the recognized value of pond wetlands even when they are no longer used in farming. Thus, this study can support educational materials for eco-experience and can be applied in the conservation of Korean pond wetlands.

Evaluation Of The Capacity Of Granulation In Surgical Wounds with Condensed Tannins in Matrices Tio2.

2012 ◽  
Vol 1479 ◽  
pp. 63-68 ◽  
Author(s):  
José Albino M. Rodrìguez ◽  
José Rutilio M. López ◽  
Genaro C. Gutiérrez ◽  
Marco-Antonio G Coronel ◽  
Enrique S. Mora ◽  
...  
Keyword(s):  
Condensed Tannins ◽  
Sol Gel ◽  
Cell Activity ◽  
Isotonic Saline ◽  
The Body ◽  
Inorganic Materials ◽  
Additional Advantage ◽  
Surgical Wounds ◽  
Temperature Ranges ◽  
The Right

ABSTRACT.The nanoencapsulation in biocompatible inorganic materials with human cell activity is a leading technology to control the process of releasing the drug in the right place. At present, the sol-gel process has emerged as a promising platform for the immobilization, stabilization and encapsulation of biological molecules such as enzymes, antibodies, microorganisms, and a variety of drugs. The matrices obtained are chemically inert, hydrophilic and easy synthesis. They have high mechanical strength, thermal stability in wide temperature ranges and absorb organic solvents so insignificant compared with other organic polymers. They are resistant to microbial attack and exhibit high biocompatibility with the body, as provided for implantation in situ in the treatment of various diseases. An additional advantage is that it provides viability encapsulated molecules, since these matrices act as reservoirs of water thus helping to maintain the biological activity of enzymes, antibodies, cells, and drugs for the moisture level required for the molecule. We used the action of the active ingredients of tepezcohuite (condensed tannins) to assess the capacity aseptic surgical wound healing than 1 cm in diameter in New Zealand white rabbits. Experimentally and statistically demonstrating the effectiveness of healing nanoreservoirs Tan/TiO2-150 the weight of tannins by 60% compared to condensed tannins as such, TiO2and isotonic saline.

scholarly journals Principals of innate and adaptive immunity. Immunity to microbes & fundamental concepts in immunology

2021 ◽  
Vol 10 (3) ◽  
pp. 188-197
Author(s):  
Andrew Kiboneka
Keyword(s):  
Immune Response ◽  
Immune Cells ◽  
Chemokine Receptors ◽  
The Body ◽  
Innate Immune ◽  
Lymphoid Cells ◽  
Biologically Active ◽  
Surface Receptors ◽  
Bacterial Surfaces ◽  
Cellular Immune

Microorganisms such as bacteria that penetrate the epithelial surfaces of the body for the first time are met immediately by cells and molecules that can mount an innate immune response. Phagocytic macrophages conduct the defense against bacteria by means of surface receptors that are able to recognize and bind common constituents of many bacterial surfaces. Bacterial molecules binding to these receptors trigger the macrophage to engulf the bacterium and also induce the secretion of biologically active molecules. Activated macrophages secrete cytokines, which are defined as proteins released by cells that affect the behavior of other cells that bear receptors for them. They also release proteins known as chemokines that attract cells with chemokine receptors such as neutrophils and monocytes from the bloodstream. Macrophages in response to bacterial constituents initiate the process known as inflammation. Antigen-presenting cells (APCs) are a heterogeneous group of immune cells that mediate the cellular immune response by processing and presenting antigens for recognition by certain lymphocytes such as T cells. Classical APCs include dendritic cells, macrophages, Langerhans cells and B cells. Innate lymphoid cells (ILCs) are immune cells that belong to the lymphoid lineage but do not express antigen-specific receptors. These cells have important functions in innate immune responses to infectious microorganisms and in the regulation of homeostasis and inflammation.

scholarly journals Natural hybrid silica/protein superstructure at atomic resolution

2020 ◽  
Vol 117 (49) ◽  
pp. 31088-31093
Author(s):  
Stefan Görlich ◽  
Abisheik John Samuel ◽  
Richard Johannes Best ◽  
Ronald Seidel ◽  
Jean Vacelet ◽  
...  
Keyword(s):  
Tertiary Structure ◽  
Three Dimensional ◽  
Inorganic Materials ◽  
Atomic Resolution ◽  
Axial Filament ◽  
X Ray Crystallography ◽  
Organic Hybrid ◽  
Hybrid Silica ◽  
Transmission Electron

Formation of highly symmetric skeletal elements in demosponges, called spicules, follows a unique biomineralization mechanism in which polycondensation of an inherently disordered amorphous silica is guided by a highly ordered proteinaceous scaffold, the axial filament. The enzymatically active proteins, silicateins, are assembled into a slender hybrid silica/protein crystalline superstructure that directs the morphogenesis of the spicules. Furthermore, silicateins are known to catalyze the formation of a large variety of other technologically relevant organic and inorganic materials. However, despite the biological and biotechnological importance of this macromolecule, its tertiary structure was never determined. Here we report the atomic structure of silicatein and the entire mineral/organic hybrid assembly with a resolution of 2.4 Å. In this work, the serial X-ray crystallography method was successfully adopted to probe the 2-µm-thick filaments in situ, being embedded inside the skeletal elements. In combination with imaging and chemical analysis using high-resolution transmission electron microscopy, we provide detailed information on the enzymatic activity of silicatein, its crystallization, and the emergence of a functional three-dimensional silica/protein superstructure in vivo. Ultimately, we describe a naturally occurring mineral/protein crystalline assembly at atomic resolution.

scholarly journals The Largest Bio-Silica Structure on Earth: The Giant Basal Spicule from the Deep-Sea Glass SpongeMonorhaphis chuni

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Xiaohong Wang ◽  
Lu Gan ◽  
Klaus P. Jochum ◽  
Heinz C. Schröder ◽  
Werner E. G. Müller
Keyword(s):  
Deep Sea ◽  
Mechanical Stability ◽  
Medical Science ◽  
Silica Matrix ◽  
Basic Knowledge ◽  
Pure Silicon ◽  
Axial Canal ◽  
Siliceous Sponges ◽  
Strength And Stiffness

The depth of the ocean is plentifully populated with a highly diverse fauna and flora, from where the Challenger expedition (1873–1876) treasured up a rich collection of vitreous sponges [Hexactinellida]. They have been described by Schulze and represent the phylogenetically oldest class of siliceous sponges [phylum Porifera]; they are eye-catching because of their distinct body plan, which relies on a filigree skeleton. It is constructed by an array of morphologically determined elements, the spicules. Later, during the German Deep Sea Expedition “Valdivia” (1898-1899), Schulze could describe the largest siliceous hexactinellid sponge on Earth, the up to 3 m highMonorhaphis chuni, which develops the equally largest bio-silica structures, the giant basal spicules (3 m × 10 mm). With such spicules as a model, basic knowledge on the morphology, formation, and development of the skeletal elements could be elaborated. Spicules are formed by a proteinaceous scaffold which mediates the formation of siliceous lamellae in which the proteins are encased. Up to eight hundred 5 to 10 μm thick lamellae can be concentrically arranged around an axial canal. The silica matrix is composed of almost pure silicon and oxygen, providing it with unusual optophysical properties that are superior to those of man-made waveguides. Experiments indicated that the spicules functionin vivoas a nonocular photoreception system. In addition, the spicules have exceptional mechanical properties, combining mechanical stability with strength and stiffness. Like demosponges the hexactinellids synthesize their silica enzymatically, via the enzyme silicatein. All these basic insights will surely contribute also to a further applied utilization and exploration of bio-silica in material/medical science.

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