Elastic Cuticle Research Articles

Validation of metaxin-2 deficient C. elegans as a model for MandibuloAcral Dysplasia associated to mtx-2 (MADaM) syndrome

MandibuloAcral Dysplasia associated to MTX2 gene (MADaM) is a recently described progeroid syndrome (accelerated aging disease) whose clinical manifestations include skin abnormalities, growth retardation, and cardiovascular diseases. We previously proposed that mtx-2-deficient C. elegans could be used as a model for MADaM and to support this, we present here our comprehensive phenotypic characterization of these worms using atomic force microscopy (AFM), transcriptomic, and oxygen consumption rate analyses. AFM analysis showed that young mtx-2-less worms had a significantly rougher, less elastic cuticle which becomes significantly rougher and less elastic as they age, and abnormal mitochondrial morphology. mtx-2 C. elegans displayed slightly delayed development, decreased pharyngeal pumping, significantly reduced mitochondrial respiratory capacities, and transcriptomic analysis identified perturbations in the aging, TOR, and WNT-signaling pathways. The phenotypic characteristics of mtx-2 worms shown here are analogous to many of the human clinical presentations of MADaM and we believe this validates their use as a model which will allow us to uncover the molecular details of the disease and develop new therapeutics and treatments.

Appearance of a transparent protrusion containing two pairs of legs on the apodous ring preceding the anamorphic molt in a millipede, Niponia nodulosa

BackgroundArthropods gradually change their forms through repeated molting events during postembryonic development. Anamorphosis, i.e., segment addition during postembryonic development, is seen in some arthropod lineages. In all millipede species (Myriapoda, Diplopoda), for example, postembryonic processes go through anamorphosis. Jean-Henri Fabre proposed 168 years ago the “law of anamorphosis”, that is, “new rings appear between the penultimate ring and the telson” and “all apodous rings in a given stadium become podous rings in the next stadium”, but the developmental process at the anamorphic molt remains largely unknown. In this study, therefore, by observing the morphological and histological changes at the time of molting, the detailed processes of leg- and ring-addition during anamorphosis were characterized in a millipede, Niponia nodulosa (Polydesmida, Cryptodesmidae).ResultsIn the preparatory period, a few days before molting, scanning electron microscopy, confocal laser scanning microscopy, and histological observations revealed that two pairs of wrinkled leg primordia were present under the cuticle of each apodous ring. In the rigidation period, just prior to molt, observations of external morphology showed that a transparent protrusion was observed on the median line of the ventral surface on each apodous ring. Confocal laser scanning microscopy and histological observations revealed that the transparent protrusion covered by an arthrodial membrane contained a leg bundle consisting of two pairs of legs. On the other hand, ring primordia were observed anterior to the telson just before molts.ConclusionsPreceding the anamorphic molt in which two pairs of legs are added on an apodous ring, a transparent protrusion containing the leg pairs (a leg bundle) appears on each apodous ring. The morphogenetic process of the rapid protrusion of leg bundles, that is enabled by thin and elastic cuticle, suggested that millipedes have acquired a resting period and unique morphogenesis to efficiently add new legs and rings.

Biomechanical properties of the tomato (Solanum lycopersicum) fruit cuticle during development are modulated by changes in the relative amounts of its components

In this study, growth-dependent changes in the mechanical properties of the tomato (Solanum lycopersicum) cuticle during fruit development were investigated in two cultivars with different patterns of cuticle growth and accumulation. The mechanical properties were determined in uniaxial tensile tests using strips of isolated cuticles. Changes in the functional groups of the cuticle chemical components were analysed by attenuated total reflectance-Fourier transform infrared (ATR-FTIR). The early stages of fruit growth are characterized by an elastic cuticle, and viscoelastic behaviour only appeared at the beginning of cell enlargement. Changes in the cutin:polysaccharide ratio during development affected the strength required to achieve viscoelastic deformation. The increase in stiffness and decrease in extensibility during ripening, related to flavonoid accumulation, were accompanied by an increase in cutin depolymerization as a result of a reduction in the overall number of ester bonds. Quantitative changes in cuticle components influence the elastic/viscoelastic behaviour of the cuticle. The cutin:polysaccharide ratio modulates the stress required to permanently deform the cuticle and allow cell enlargement. Flavonoids stiffen the elastic phase and reduce permanent viscoelastic deformation. Ripening is accompanied by a chemical cleavage of cutin ester bonds. An infrared (IR) band related to phenolic accumulation can be used to monitor changes in the cutin esterification index.

A Simple Technique to Stage the Moult of Penaeus monodon

Growth in crustaceans and other arthropods is interrupted by cyclical moults, in which the old cuticle or exoskeleton is shed, and in the intervening growth phases the soft tissue swells and a new elastic cuticle gradually thickens and hardens. Marine prawns, Penaeus monodon, from a commercial farm in northern Queensland, Australia, were studied alive to assess their growth and moulting stages. The median part of the setae of inner uropods was examined by light microscopy. A finely graded classification of five stages and substages of postmoult, stage A consisting of substages A1 and A2, and stage B (1-16 hours); intermoult, stage C (1 day); premoult, stage D consisting of substages D1, D2 and D3/D4 (2-12 days) and ecdysis, stage E (about one minute) are described and illustrated. Ecdysis took place at night. Rapid and repetitive moult staging in individual prawns can be carried out without sacrificing the prawns.

Cell wall components affect mechanical properties: studies with thistle flowers

Pollen presentation of Cirsium horridulum depends partially on the thigmonastic contraction of staminal filaments. Although the elastic cuticle is a major component in filament elasticity, it is not clear how the cell wall copes with the shape change. Based on mechanical studies, FT-IR spectroscopy and biochemical analyses we investigated the relationship between cell wall composition and elastic properties using thistle floral tissues as a model. EDTA-extractable pectin correlated with the increased elasticity of the filament and the basal style, suggesting that pectin plays a major role in the elastic behavior of soft tissues. In contrast, covalently linked pectin contributes to the stiffness of the upper style and corolla. Mechanical tests contrasting the soft basal and rigid apical parts of the style after incubation in solutions designed to alter the pectin network confirmed these results. The rigid corolla contained more cellulose than the softer style and filaments. The cellulose-associated xyloglucan of the style and filament cell walls increase the flexibility of cell walls.

Biochemical analysis of elastic and rigid cuticles of Cirsium horridulum.

The cuticle is a complex structure of soluble lipids, lipid polymers and polysaccharides. In addition to its functions to reduce water loss and provide a protective barrier, its mechanical properties may be significant to plant growth and development. We investigated the cuticle of Cirsium horridulum Michx. because of its involvement in the thigmonastic contraction of staminal filaments. The staminal filaments and portions of the style are surrounded by a highly elastic cuticle in contrast to the rigid cuticle of the corolla and leaves. Our aim was to determine if the biochemical composition affected the elasticity of the cuticle. We discovered that the ratio of carbohydrates to lipids is 1:7 in floral parts but 2:1 in leaf cuticle. Esterified cutin components represented about 80% of the cuticle and di-hydroxyhexadecanoic acids were the major monomers of cutin, regardless of origin. The cutin of elastic tissues is characterized by a higher content of tri-hydroxy monomers than the cutin of rigid tissues. The data suggest that hydroxyl groups enhance the hydrophilic character of the cuticle and contribute to cuticular elasticity.

Life cycle and parasitic interaction of the lizard-parasitizing mite Ophionyssus galloticolus (Acari: Gamasida: Macronyssidae), with remarks about the evolutionary consequences of parasitism in mites.

Wild-caught specimens of the lacertid lizard Gallotia galloti eisentrauti from the Canary Island of Tenerife were checked for ectoparasites. The parasitic gamasid mite Ophionyssus galloticolus Fain and Bannert (2000) was very abundant on these lizards. Additionally, parasitism by larvae of two species of Trombiculidae (Prostigmata: Parasitengona) was observed. O. galloticolus was reared in the laboratory on its natural host in order to investigate its life cycle, reproductive biology, and development. The life history of O. galloticolus is documented in detail and compared to literature data of other Ophionyssus species. O. galloticolus was found to be similar to other species of the same genus with respect to the duration of development, the precopulatory association of protonymphs, and the arrhenotokous development of eggs. However, it seems to be more tolerant towards low relative humidity and longer starvation periods than other Ophionyssus species. Evolutionary transformations of the life-history pattern of this genus and other parasitic mites in comparison to its predatory precursors involve a reduction or partial suppression of ontogenetic instars in order to decrease mortality during host-seeking phases, and a compensating increase in growth capacity of the remaining feeding instars facilitated by replacement of sclerites through elastic cuticle or by growth of new cuticle unrelated to a moult (neosomy).

Frictional surfaces of the elytra-to-body arresting mechanism in tenebrionid beetles (Coleoptera : Tenebrionidae) : design of co-opted fields of microtrichia and cuticle ultrastructure

In beetles, the system responsible for an attachment of forewings (elytra) to the thorax consists of interlocking fields of microtrichia (MT) located between thorax and body and between left and right elytra. The present study provides comparative data about microtrichia design on the thorax and elytra in three species of tenebrionid beetles (Tribolium castaneum, Tenebrio molitor, Zophobas rugipes) (Coleoptera : Tenebrionidae), which are different in their size. The length, width, density and directionality of microtrichia in 13 MT fields (4 on the thorax, 1 on the abdomen, 7 on the elytra, and 1 on the costal vein of the hindwing) were quantified. (1) Parameters studied are dependent on the dimension of an insect. The length of the microtrichia of most fields compared increases with an increase in body size. The MT width in the majority of fields increases with an increase in the elytra length. The MT density decreases with an increase in the elytra length. (2) Both width and length of microtrichia increase with an increase in the distance between single MT. The density of outgrowths increases with an increase in their length and width. (3) The fields oriented along the same spatial axis constitute functional groups responsible for a particular direction. Co-opted fields can be oriented in the same or opposite directions. (4) The design of MT correlates in co-opted surfaces. There are 3 field groups, which were stated as functionally corresponding to one another : the medial, anterio-lateral, and posterio-lateral. The lengths and widths of microtrichia from fields of these functional groups were quite similar in corresponding fields. Length-to-width ratios of MT in elytral fields were usually weakly correlated with those of thoracic fields. The distances between microtrichia on the elytra surface directly depended on those of the thorax. Distance-to-width ratio of MT of one surface slightly increased with an increase in this parameter on the co-opted surface. The MT densities on co-opted fields were usually quite different. (5) The ultrastructure of the cuticle suggests differences in the material properties of the cuticle between MT fields. The thoracic fields usually consist of elastic cuticle, whereas elytral fields are much harder. Usually, a MT field of elastic cuticle corresponds to the field composed of hard cuticles. The study also provides information about the ultrastructure of epidermal cells and about the design of pore channels, which are presumably responsible for production and transport of an adhesive secretion into the area of contact between lateral fields. Sensory organs monitoring contact between co-opted binding sites were also studied. The results of this study may aid in understanding the morphological basis of cuticular microsculptures acting as frictional devices.

Preliminary Characterization of Resilin Isolated from the Cockroach,Periplaneta Americana

AbstractWe would like to mimic the mechanical properties of animal systems for the development of novel materials. Insect cuticle serves as one source of inspiration for the design of these materials. Cuticle is composed of chitin embedded in a protein matrix which may also contain plasticizers, fillers, crosslinkers, and minerals. The specific properties of the cuticle depend on the type, amount and interactions between each component. We are renewing the investigation of the elastic cuticle, resilin. Resilin, a protein-based elastomer first described in the early 1960s, has properties which have been reported to be most like those of ideal rubbers. We have examined resilin isolated from the prealar arms of the cockroach,Periplaneta americana. The results of amino acid analysis are in good agreement with earlier data reported for resilin. A series of tryptic fragments have been isolated and sequenced. These peptides have been used for the design of oligonucleotide probes for the identification of the gene(s) from a teneral cockroach cDNA library. A biopolymer, based on one tryptic fragment, has been designed and synthesized. We are continuing to treat resilin with residue specific proteases in order to map the resilin protein.

Embryonic Cuticles of Artemia during Diapause and Hatching: Insights from Comparison with Other Branchiopoda

The first embryonic cuticle molted by a developing Eulimnadia antlei (Conchostraca) is featureless and inelastic. The second molt produces an elastic cuticle with two pouches apparently developed over anlagen of the antennae. Comparison of this situation with the data available on embryonic development and eclosion in Artemia (Anostraca) indicates that the hatching membrane in Artemia also results from a second embryonic ecdysis. Observations on anostracan, conchostracan, and notostracan eggs indicate that the outer cuticular membrane in Artemia is part of the first embryonic cuticle. Morris and Afzelius (1967) described this structure, but could not determine whether it was part of the embryonically produced cuticle or the maternally produced tertiary envelope. Information currently available indicates anostracans in the family Chirocephalidae, unlike Artemiidae, molt only one embryonic membrane.

EMBRYONIC CUTICLES OF ARTEMIA DURING DIAPAUSE AND HATCHING: INSIGHTS FROM COMPARISON WITH OTHER BRANCHIOPODA

The first embryonic cuticle molted by a developing Eulimnadia antlei (Conchostraca) is featureless and inelastic. The second molt produces an elastic cuticle with two pouches apparently developed over anlagen of the antennae. Comparison of this situation with the data available on embryonic development and eclosion in Artemia (Anostraca) indicates that the hatching membrane in Artemia also results from a second embryonic ecdysis. Observations on anostracan, conchostracan, and notostracan eggs indicate that the outer cuticular membrane in Artemia is part of the first embryonic cuticle. Morris and Afzelius (1967) described this structure, but could not determine whether it was part of the embryonically produced cuticle or the maternally produced tertiary envelope. Information currently available indicates anostracans in the family Chirocephalidae, unlike Artemiidae, molt only one embryonic membrane.

Ultrastructure of a scent scale organ with pressure discharge in male Caligo eurilochus brasiliensis (Fldr.) (Lepidoptera/ Brassolidae).

The abdominal scent apparatus of male Caligo eurilochus was examined at different ages by light, scanning and transmission electron microscopy. The glandular epithelium is covered with specialized scales and forms a pad on each side of the 4th to 6th abdominal segments. The pads are surrounded by smooth, elastic cuticle and can protrude toward the opposite hind wing hair pencil. The scales have a poreless cuticle with a fibrillar texture. They are impregnated by an oily, slowly volatile substance. The scales are elongated toward the base, forming hoods over the long cone-shaped sockets. The scale pedicel is anchored tension-free by rootlets in the central socket base. The slightly asymmetric cuticular sockets are very elastic, due to their high water content. They are stabilized by internal epicuticular rods. The release of the secretions from the cell and a possibly active microvillar transport is discussed. Different secretions are found in the space between the microvillar surface of the gland cell and the socket floor. They are probably discharged from the supraglandular space into the scale lumen by means of pressure and bending of the sockets. A flowback might be prevented by capillary effect of a "ball" of vesicles, which lies exactly above the outlet of the scale pedicel.

Scanning Electron Microscopy of the Male Nematode Physaloptera (Tetradelphynema)

Nematodes are elongate, unsegmented worms with an elastic cuticle made of protein. Few published references concerning scanning electron microscopy of nematode are available and there is paucity of information at the ultrastructural level on cuticle forming male reproductive structures. The species of the genus Physaloptera (tetradelphynema) commonly live as parasites in the adult form in the stomach of the desert rodent Gerbillus cheesmani. To date, the three-dimensional surface features of this spiruroid nematode have not been described. The main purpose of this investigation was to elucidate the surface features of the male nematode utilizing the current techniques of scanning electron microscopy.Adult worms were collected in the laboratory from the stomach of the gerbil, Gerbillus cheesmani. They were washed in PO4 buffer solution and subsequently fixed overnight in 2.5% glutaraldehyde in 0.1 M cacodylate buffer. Following fixation, the specimens were washed 3 times in buffer and sonically cleaned for 30 seconds to remove debris adhering on the body wall of the nematode.

Contractile filopodia and in vivo cell movement in the tunic of the ascidian, Botryllus schlosseri.

ABSTRACT The in vivo movement of one class of cells in the tunic of the ascidian Botryllus schlosseri has been analysed using differential interference optics and time-lapse cinematography. Long (up to 200 μm), thin (0·35–0·5 pm diameter) filopodia radiate from the cell-body into the matrix of the tunic. Movement of the cell-body consists of a series of short, jerky displacements with frequent changes in direction between successive displacements. The net displacement of the cell may be extremely small when the displacements are short and frequently change direction, or considerable when successive displacements show a persistence of direction (up to 114 μm in 60 min). Deformation of the elastic cuticle covering the tunic at points of attachment of the filopodia has been used to record qualitatively changes in tension in the filopodia. Correlation of the changes in tension with changes in length of the filopodia and movement of the cell-body have permitted the following conclusions. Active contractions of filopodia (i.e. increase in tension during shortening) stretch and move the cell-body. These movements exert a force on trailing or opposing filopodia. Relaxations of filopodia (i.e. decrease in tension during lengthening) result in small movements of the cell-body due to the recoil of tension in the cell-body and opposing filopodia. The position of the cell-body in space at any one instant in time is therefore the resultant of the forces developed in all the filopodia. Movement results from unilateral modulation of the tension developed in the filopodia. Active contractions play a more significant role in movement than relaxations.

A novel relationship between two types of elastic cuticle in the locust

Entomologia Experimentalis et ApplicataVolume 16, Issue 1 p. 135-136 A novel relationship between two types of elastic cuticle in the locust J. F. V. Vincent, J. F. V. Vincent Department of Zoology, The University, Building 1, Spur J, Earley Gate, Whiteknights Road, Reading, Berkshire, EnglandSearch for more papers by this author J. F. V. Vincent, J. F. V. Vincent Department of Zoology, The University, Building 1, Spur J, Earley Gate, Whiteknights Road, Reading, Berkshire, EnglandSearch for more papers by this author First published: March 1973 https://doi.org/10.1111/j.1570-7458.1973.tb00256.xCitations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume16, Issue1March 1973Pages 135-136 RelatedInformation

Biology and physics of locust flight. V. Strength and elasticity of locust cuticle

Elastic deformations of the cuticle play a major role in the energetics of flying locusts but the literature provides no relevant information about the elastic properties of any arthropod cuticle. The results are therefore discussed both in relation to locust flight and in relation to strength and elasticity of organic materials in general. InSchistocerca gregariaForskal there are two types of elastic cuticle, ordinarysolid cuticleandrubber-like cuticle. The characteristic material in the latter type is a newly discovered protein rubber,resilin. Samples of both were studied under static and dynamic conditions. The tensile properties of solid cuticle from various parts of the body (hind tibia, pleural wall, forewing) are similar to those of oak wood and of synthetic resins reinforced with cellulose; the static coefficient of elasticity (dcr/de) is 800 to 1000 kg/mm2and the tensile strength 8 to 10 kg/mm2, corresponding to an ultimate extension of 2 to 3 %. At moderate loads, the tensile and compressive moduli are of equal magnitude, but it is argued that the effect of tanning (hardening) is to increase the compressive strength and modulus rather than the tensile properties. Static loading results in lasting deformation. The dynamic modulus is of the same magnitude as the static modulus (forewing), at least up to 5 kg mm-2s-1and, provided the tension does not exceed 0-5 kg/mm2, the loss factor is less than 0.1. The rubber-like sample (prealar arm) consists of parallel lamellae of chitin (0.2μ thick) glued together by sheets of resilin (about 3μ thick). It behaves like a solid when extended in the direction of the lamellae but otherwise like a rubber, the elastic modulus being 0.2 kg/mm2. The swelling pressure of resilin does not play any direct role but swelling alters the geometry and, to a small extent, the elastic modulus. It is suggested that the animal controls the stiffness of its rubber-like structures by altering the swelling equilibrium chemically which, in a model experiment, is done by blocking the free amino groups. Rubber-like cuticle does not encounter any permanent deformation which is attributed to the known lack of flow of pure resilin. Within the biological rate of deformation (up to 6 unit lengths per second), the dynamic stiffness remains within 4 % of the static value and the loss factor is only 0.03, i.e. less than for other natural or synthetic rubbers. A three-component model of arthropod cuticle is suggested. It accounts for the enormous differences in mechanical properties between adjacent parts and also for the fact that strict structural and developmental continuity is observed between the parts. It has three components: (1) crystalline chitin, (2) a rubber-like protein which may act as a deformable matrix and which entraps, (3) water-soluble proteins which can undergo proper tanning.