Microscopy of crustacean cuticle: formation of a flexible extracellular matrix in moulting sea slaters Ligia pallasii

AbstractStructural and functional properties of exoskeleton in moulting sea slaters Ligia pallasii from the Eastern Pacific coast were investigated with CT scanning and electron microscopy. Ultrastructure of preecdysial and postecdysial cuticular layers was described in premoult, intramoult and postmoult animals. Cuticle is a flexible extracellular matrix connected to the epidermal cells through pore channels. During premoult epicuticle and exocuticle are formed and during intramoult and postmoult endocuticular lamellae are deposited and the cuticle is progressively constructed by thickening and mineralization. Cuticle permeability, flexibility and waterproofing capacity change accordingly. Elaboration of epicuticular scales connected to an extensive network of nanotubules, establish its anti-adhesive and hydrophobic properties. Labelling with gold conjugated WGA lectins on Tokuyashu thawed cryosections exposes differences in chitin content between exocuticle and endocuticle. Histochemical staining of cuticle shows presence of acidic carbohydrates/glycoconjugates and lipoproteins in epicuticular layer. Chitin microfibrils are formed at the microvillar border of epidermal cells with abundant Golgi apparatus and secretory vesicles. Numerous spherules associated with nanotubules were observed in the ecdysial space in intramoult animals. The mineral component of the cuticle as visualized with CT scanning indicates progressive mineral resorption from the posterior to the anterior half of the body in premoult animals, its translocation from the anterior to posterior part during intramoult and its progressive deposition in the posterior and anterior exoskeleton during postmoult. Cuticle of sea slaters is a unique biocomposite and biodynamic material constantly reconstructed during frequent moults, and adapted to specific physical and biotic conditions of the high intertidal rocky zone.

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Ultrastructure and formation of the hooked setae in Owenia fusiformis delle Chiaje, 1842: implications for annelid phylogeny

Canadian Journal of Zoology ◽

10.1139/z96-243 ◽

1996 ◽

Vol 74 (12) ◽

pp. 2143-2153 ◽

Cited By ~ 34

Author(s):

Karsten Meyer ◽

Thomas Bartolomaeus

Keyword(s):

Extracellular Matrix ◽

Basal Lamina ◽

Functional Significance ◽

Follicle Cell ◽

Sister Group ◽

Epidermal Cells ◽

The Body ◽

Monophyletic Group ◽

Follicle Cells

Several members of the Annelida bear apically curved or hooked setae that are aligned in a transverse row inside the neuropodial rim. Based on the hypothesis that these specific setae characterize a monophyletic group within the Annelida, the structure and development of the hooked seta in Owenia fusiformis are analysed and compared with data from other annelids with such setae. The neuropodial hooks of O. fusiformis are arranged in multiple transversal rows or setal patches on each side of the body from the fourth setiger onwards. The setae are curved distally and consist of two identical spines lying side by side at the same level. Their tips generally point ventrofrontally. Within each patch, the setae lie inside a setal follicle that consists of a basal chaetoblast, at least one follicle cell, and varying numbers of epidermal cells. Each setal patch is basally surrounded by an extracellular matrix that is continuous with the subepidermal basal lamina. An additional discontinuous extracellular matrix lies between the epidermis and the follicle cells. It is of functional significance for the attachment of the epidermal cells and seems to be related to the special organization of the setal patches, because it is absent in juveniles; they have single neuropodial rows of hooked setae per segment. New setae are formed at the dorsal and caudal edges of each patch, whereas the degeneration of setae is observed at the frontal edge of each patch. Microvilli project from the apex of the chaetoblast into canals within the fully differentiated setae. These canals remain when the microvilli are withdrawn from the seta during formation. Each hook is formed by a single large microvillus. The results of the present paper substantiate the hypothesis of a homology of the hooked setae in the Oweniida and other Annelida. These results and data from the literature support the hypothesis that the Oweniida is the sister-group of a monophylum which consists of the Terebellida, Pogonophora, and Sabellida.

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Functional analysis of chondroitin 4 sulfate constituting osseointegration

Impact ◽

10.21820/23987073.2019.8.18 ◽

2019 ◽

Vol 2019 (8) ◽

pp. 18-20

Author(s):

Shuhei Tsuchiya

Keyword(s):

Functional Analysis ◽

Extracellular Matrix ◽

Dental Implants ◽

Maxillofacial Surgery ◽

The Body ◽

Oral And Maxillofacial Surgery ◽

Direct Connection ◽

Tooth Replacement ◽

Living Bone ◽

Natural Tooth

Osseointegration can be defined as a direct connection, both structural and functional, between living bone and the surface of an artificial implant. Indeed, the word comes from the Greek term for 'bone' and 'to make whole'. In dentistry, once dental implants are placed, the body will react with osseointegration, enabling the implants to become a permanent part of the jaw. There are many benefits to this type of implant, compared with traditional tooth replacement options, not least that dental implants mimic the strength and functionality of a natural tooth. Dr Shuhei Tsuchiya is a researcher based in the Division of Oral and Maxillofacial Surgery at Nagoya University, Japan, who is interested in a range of areas, including regenerative medicine and the extracellular matrix. One of his key preoccupations, though, is shedding light on osseointegration. He and his team are working to unravel the mysteries of the mechanism.

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Optical Microscopy and the Extracellular Matrix Structure: A Review

Cells ◽

10.3390/cells10071760 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1760

Author(s):

Joshua J. A. Poole ◽

Leila B. Mostaço-Guidolin

Keyword(s):

Extracellular Matrix ◽

Confocal Microscopy ◽

Laser Scanning ◽

Biological Tissues ◽

The Body ◽

Stimulated Emission ◽

Substantial Part ◽

Fluorescence Lifetime Imaging ◽

Structured Illumination ◽

Structured Illumination Microscopy

Biological tissues are not uniquely composed of cells. A substantial part of their volume is extracellular space, which is primarily filled by an intricate network of macromolecules constituting the extracellular matrix (ECM). The ECM serves as the scaffolding for tissues and organs throughout the body, playing an essential role in their structural and functional integrity. Understanding the intimate interaction between the cells and their structural microenvironment is central to our understanding of the factors driving the formation of normal versus remodelled tissue, including the processes involved in chronic fibrotic diseases. The visualization of the ECM is a key factor to track such changes successfully. This review is focused on presenting several optical imaging microscopy modalities used to characterize different ECM components. In this review, we describe and provide examples of applications of a vast gamut of microscopy techniques, such as widefield fluorescence, total internal reflection fluorescence, laser scanning confocal microscopy, multipoint/slit confocal microscopy, two-photon excited fluorescence (TPEF), second and third harmonic generation (SHG, THG), coherent anti-Stokes Raman scattering (CARS), fluorescence lifetime imaging microscopy (FLIM), structured illumination microscopy (SIM), stimulated emission depletion microscopy (STED), ground-state depletion microscopy (GSD), and photoactivated localization microscopy (PALM/fPALM), as well as their main advantages, limitations.

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Redescription of Paradiplozoon hemiculteri (Monogenea, Diplozoidae) from the type host Hemiculter leucisculus, with neotype designation

Parasite ◽

10.1051/parasite/2018004 ◽

2018 ◽

Vol 25 ◽

pp. 4 ◽

Cited By ~ 3

Author(s):

Dagmar Jirsová ◽

Xuejuan Ding ◽

Kristína Civáňová ◽

Eliška Jirounková ◽

Jana Ilgová ◽

...

Keyword(s):

Southern China ◽

Phylogenetic Analyses ◽

Posterior Part ◽

Original Description ◽

Molecular Data ◽

The Body ◽

Type Host ◽

Hemiculter Leucisculus ◽

Morphological And Molecular Data ◽

Median Plate

Paradiplozoon hemiculteri (Ling, 1973), a member of the Diplozoidae, parasitizes the gills of Asian fish. Not only is the type material unavailable for this species, the original description was poor and somewhat conflicting, and adequate molecular data were not available. What is more, the available morphological and molecular data are inconsistent and fluctuate significantly. Here, we present a redescription of P. hemiculteri based on morphological and molecular data from new isolates collected from the type host, the sharpbelly Hemiculter leucisculus (Basilewsky, 1855), captured at the neotype locality (Shaoguan, Guangdong Province, southern China); a neotype for P. hemiculteri was designated from this collection. The length and width of the body, buccal suckers, pharynx, attachment clamps, sickle and the central hook handle were all measured and the shape of the anterior and posterior part of the median plate and anterior and posterior joining sclerites accurately documented. Phylogenetic analyses based on the sequences of the second rDNA internal transcribed spacer (ITS2) indicated that all new samples clustered together and differed clearly from sequences attributed to P. hemiculteri, which are deposited in GenBank. Our results confirm that P. hemiculteri is the only diplozoid that has demonstrably been found on the gills of H. leucisculus to date.

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Spatial and temporal variation in body mass and the blubber, muscle and visceral fat content of North Atlantic common minke whales

J. Cetacean Res. Manage. ◽

10.47536/jcrm.v21i1.150 ◽

2020 ◽

Vol 21 (1) ◽

pp. 59-70

Author(s):

Thorvaldur Gunnlaugsson

Keyword(s):

Body Mass ◽

North Atlantic ◽

Visceral Fat ◽

Energy Content ◽

Posterior Part ◽

The Body ◽

Spatial And Temporal Variation ◽

Total Body Mass ◽

The North ◽

Minke Whales

The exponent for predicting total body mass from length has been studied in many species and here data on common minke whales from areas in the North Atlantic is added from both Icelandic and Norwegian research catches. The exponent was found to be not significantly different from 3. In addition seasonal changes in body mass and in the parts of blubber, muscle and visceral fat are reported. The exponent for how blubber mass increases with length is lower than 3. In all cases a significant increase over the season was detected, in particular for the mature animals, and also in girth measurements, particularly at the posterior part of the body. Pregnant females had significantly more blubber than other whales. These results agree with studies on blubber thickness measurements and tissue energy content of Icelandic baleen whales and observed changes in the ecosystem around Iceland during the research period.

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The Eyes and the Photonegative Behaviour of Nephtys (Annelida, Polychaeta)

Journal of Experimental Biology ◽

10.1242/jeb.33.3.461 ◽

1956 ◽

Vol 33 (3) ◽

pp. 461-477

Author(s):

R. B. CLARK

Keyword(s):

Light Intensity ◽

Light Beam ◽

Linear Function ◽

Posterior Part ◽

Dorsal Surface ◽

Epidermal Cells ◽

Small Species ◽

Accessory Cells ◽

Vacuolated Cells ◽

The Brain

1. The photoreceptors found in the Nephtyidae are: (a) Two pairs of vacuolated cells lying in pigment cups, with accessory cells, embedded in the posterior part of the supra-oesophageal ganglion. (b) One or two cells, which may or may not be vacuolated, on either side, lying a little anterior to the ganglion. (c) Undifferentiated epidermal cells surrounded by pigment granules may be photosensitive. 2. There are both morphological and behavioural grounds for concluding that the prostomial eyes of Nephtys are homologous with the eyes of Nereis, and that they are involved in the same types of behaviour. 3. The frequency with which Nephtys swims is, within limits, a linear function of the light intensity. Although the ganglionic eyes are directional receptors the worm does not orientate itself in a light beam; presumably the light reaching them is too diffuse. In the very small species N. cornuta, the eyes are close to the surface of the brain and the worm does orientate itself in a light beam. 4. Swimming is an essential prelude to burrowing, and the brighter the light the more frequently the worm swims and the sooner it is buried. Activity in light can be inhibited by stimulating receptors on the dorsal surface of the animal by contact.

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MUSCLE TENSION AND REFLEXES IN THE EARTHWORM

The Journal of General Physiology ◽

10.1085/jgp.5.3.327 ◽

1923 ◽

Vol 5 (3) ◽

pp. 327-333 ◽

Cited By ~ 12

Author(s):

A. R. Moore

Keyword(s):

Nerve Cord ◽

Ventral Nerve Cord ◽

Body Wall ◽

Muscle Tension ◽

Posterior Part ◽

The Body ◽

Entire Length ◽

Sensory Cells ◽

Ventral Region ◽

Anterior Segments

1. By the use of preparations of earthworm in which the cutaneous receptors have been anesthetized with a solution of M/8 MgCl2, it is shown that peristalsis can be initiated by tension alone. 2. The receptors of the tension reflex are the intermyal sensory cells of the ventral region of the body wall. 3. It is concluded that Straub obtained the tension reflex because his preparations contained the intermyal receptors; Budington was unable to observe the tension reflex in any preparation from which the intermyal receptors had been removed. 4. Intermyal receptors are the receptors of the following reaction: Passive unilateral tension of the posterior part of an earthworm induces active homolateral tension of the musculature of the anterior segments, and results in the course of progress being brought into line with the enforced orientation of the tail. This reaction is termed the homostrophic reflex. 5. The receptors for the reaction are distributed throughout the entire length of the worm, the effectors are limited to the anterior 15 to 20 segments. The impulse is conducted by the ventral nerve cord. 6. The interaction of the homostrophic reflex and tropisms is considered.

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Positioning and maintenance of embryonic body wall muscle attachments in C. elegans requires the mup-1 gene

Development ◽

10.1242/dev.111.3.667 ◽

1991 ◽

Vol 111 (3) ◽

pp. 667-681 ◽

Cited By ~ 3

Author(s):

P.Y. Goh ◽

T. Bogaert

Keyword(s):

Extracellular Matrix ◽

Body Wall ◽

Early Stage ◽

Muscle Growth ◽

The Body ◽

Body Wall Muscle ◽

C Elegans ◽

Extracellular Matrix Molecule ◽

Extracellular Matrix Components ◽

Body Wall Muscles

As part of a general study of genes specifying a pattern of muscle attachments, we identified and genetically characterised mutants in the mup-1 gene. The body wall muscles of early stage mup-1 embryos have a wild-type myofilament pattern but may extend ectopic processes. Later in embryogenesis, some body wall muscles detach from the hypodermis. Genetic analysis suggests that mup-1 has both a maternal and a zygotic component and is not required for postembryonic muscle growth and attachment. mup-1 mutants are suppressed by mutations in several genes that encode extracellular matrix components. We propose that mup-1 may encode a cell surface/extracellular matrix molecule required both for the positioning of body wall muscle attachments in early embryogenesis and the subsequent maintenance of these attachments to the hypodermis until after cuticle synthesis.

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Odontogenic keratocyst: diagnostic characteristics and conservative surgical treatment

International Journal of Medical and Surgical Sciences ◽

10.32457/ijmss.v8i4.1655 ◽

2021 ◽

pp. 1-12

Author(s):

Javier Sánchez Sánchez ◽

José Aguilar Maldonado ◽

Karem Barreno Haro

Keyword(s):

Third Molar ◽

Posterior Part ◽

En Bloc Resection ◽

Bloc Resection ◽

The Body ◽

Odontogenic Keratocyst ◽

High Recurrence Rate ◽

En Bloc ◽

Dental Lamina ◽

Diagnostic Characteristics

Keratocyst is a benign odontogenic lesion with aggressive behavior, probably derived from the dental lamina. It is frequently located in the posterior part of the mandibular bone in the area of the third molar, mandibular angle and can progress towards the ramus and the body, presenting a direct association with retained dental organs. There is a wide variety of techniques for the treatment of this lesion, such as decompression, marsupialization, enucleation, and en bloc resection, as well as the combination of these with adjuvant methods. The interest in this lesion stems from its high recurrence rate, which is estimated to be 20-30% in the general population, however, at present the use of conservative treatments such as marsupialization and decompression has been chosen. demonstrated greater effectiveness and less recurrence. This is why after treating the lesions it is important to give a long-term follow-up. The objective of the publication is to present the report of a clinical case of a 21-year-old male patient with a diagnosis of odontogenic keratocyst treated with a decompression technique for five months for subsequent surgical enucleation. It has been proven that decompression treatment followed by enucleation and accompanied by adjuvant methods is an adequate therapeutic management for keratocysts as it demonstrates its lower rate of recurrence and its noble behavior with neighboring vital structures. However, in all cases, regular monitoring should be carried out to prevent recurrence of the lesion.

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Abstract 12: The Effect of Extracellular Matrix Stiffness on Human Bone Marrow-Derived Mesenchymal Stem Cell Differentiation

Circulation Research ◽

10.1161/res.115.suppl_1.12 ◽

2014 ◽

Vol 115 (suppl_1) ◽

Author(s):

Alison L Müller ◽

Yun Li ◽

Boris Hinz ◽

Darren H Freed

Keyword(s):

Bone Marrow ◽

Extracellular Matrix ◽

Heart Surgery ◽

Smooth Muscle Actin ◽

Open Heart Surgery ◽

Human Mesenchymal Stem Cells ◽

Stem Cell Differentiation ◽

The Body ◽

Surface Tensions ◽

Alpha Smooth Muscle Actin

Differentiation of human mesenchymal stem cells (hMSCs) has been shown to be influenced by the surrounding microenvironment. It is important to understand the physiological implications of the hMSC microenvironment regarding differentiation within the body, especially in patients with cardiovascular disease. We are interested in understanding the influence of differing extracellular matrix (ECM) stiffness found in the body that the MSC encounters during its journey from the bone marrow to the infarct scar in patients recovering from a myocardial infarction. As hMSCs must respond rapidly to their environment, we also investigated the influence of microRNA at different surface tensions. HMSCs were isolated from the bone marrow of patients undergoing open heart surgery and cultured in standard DMEM/F12 with 20% FBS. We plated these cells on fibronectin-coated plates with surface tensions of 2kPa, simulating bone marrow; 15kPa, simulating left ventricle; and 100kPa, simulating a fibrotic environment. Protein and mRNA were collected for further analysis. Our data have revealed that softer surface tensions, representing a bone marrow-undifferentiating environment, cause a decrease in the protein expression of EDA-fibronectin and alpha-smooth muscle actin. There were also increases in mRNA of myosin heavy chain-9 and 10, and collagen-1. Softer surface tensions also show a slight increase in miR-301a, although at 15kPa, miR-301a expression is increased even further. Our lab has previously shown that miR-301a is involved in maintaining a proliferative phenotype of hMSCs. Interestingly, Dicer1, responsible for processing microRNAs, is upregulated at softer surface tensions and attenuated at 15kPa. Dicer1 mRNA expression is attenuated at 15kPa. These results indicate that ECM stiffness influences hMSC differentiation and the increase in Dicer1 found with softer matrices could represent an umbrella miRNA inhibition effect to effectively suppress hMSC differentiation.

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