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Woodrow C, Cullen DA, Montealegre-Z F, Gonzalez-Rodriguez J. Non-invasive characterization of the elastic protein resilin in insects using Raman spectroscopy. Int J Biol Macromol 2024; 254:127967. [PMID: 37944738 DOI: 10.1016/j.ijbiomac.2023.127967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 10/10/2023] [Accepted: 11/06/2023] [Indexed: 11/12/2023]
Abstract
Resilin is an extremely efficient elastic protein found in the moving parts of insects. Despite many years of resilin research, we are still only just starting to understand its diversity, native structures, and functions. Understanding differences in resilin structure and diversity could lead to the development of bioinspired elastic polymers, with broad applications in materials science. Here, to better understand resilin structure, we offer a novel methodology for identifying resilin-rich regions of the insect cuticle using non-invasive Raman spectroscopy in a model species, the desert locust (Schistocerca gregaria). The Raman spectrum of the resilin-rich semilunar process of the hind leg was compared with that of nearby low-resilin cuticle, and reference spectra and peaks assigned for these two regions. The main peaks of resilin include two bands associated with tyrosine at 955-962 and 1141-1203 cm-1 and a strong peak at 1615 cm-1, attributed to the α-Amide I group associated with dityrosine. We also found the chitin skeletal modes at ~485-567 cm-1 to be significant contributors to spectra variance between the groups. Raman spectra were also compared to results obtained by fluorescence spectroscopy, as a control technique. Principal component analysis of these resulting spectra revealed differences in the light-scattering properties of resilin-rich and resilin-poor cuticular regions, which may relate to differences in native protein structure and relative abundance.
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Affiliation(s)
- Charlie Woodrow
- University of Lincoln, School of Life and Environmental Sciences, Joseph Banks Laboratories, Green Lane, Lincoln LN6 7DL, United Kingdom of Great Britain and Northern Ireland
| | - Darron A Cullen
- University of Lincoln, School of Life and Environmental Sciences, Joseph Banks Laboratories, Green Lane, Lincoln LN6 7DL, United Kingdom of Great Britain and Northern Ireland; University of Hull, School of Natural Sciences, Cottingham Road, Hull, HU6 7RX, United Kingdom of Great Britain and Northern Ireland
| | - Fernando Montealegre-Z
- University of Lincoln, School of Life and Environmental Sciences, Joseph Banks Laboratories, Green Lane, Lincoln LN6 7DL, United Kingdom of Great Britain and Northern Ireland
| | - Jose Gonzalez-Rodriguez
- University of Lincoln, School of Chemistry, Joseph Banks Laboratories, Green Lane, Lincoln LN6 7DL, United Kingdom of Great Britain and Northern Ireland.
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Xing W, Lin L, Wang Z, Xiong L, Hadiatullah H, Chen W, You S, Moussian B, Wang Y, Yuchi Z. Expression and purification of snustorr snarlik protein from Plutella xylostella. Protein Expr Purif 2023; 206:106256. [PMID: 36871763 DOI: 10.1016/j.pep.2023.106256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/01/2023] [Accepted: 03/02/2023] [Indexed: 03/06/2023]
Abstract
Snustorr snarlik (Snsl) is a type of extracellular protein essential for insect cuticle formation and insect survival, but is absent in mammals, making it a potential selective target for pest control. Here, we successfully expressed and purified the Snsl protein of Plutella xylostella in Escherichia coli. Two truncated forms of Snsl protein, Snsl 16-119 and Snsl 16-159, were expressed as a maltose-binding protein (MBP) fusion protein and purified to a purity above 90% after a five-step purification protocol. Snsl 16-119, forming stable monomer in solution, was crystallized, and the crystal was diffracted to a resolution of ∼10 Å. Snsl 16-159, forming an equilibrium between monomer and octamer in solution, was shown to form rod-shaped particles on negative staining electron-microscopy images. Our results lay a foundation for the determination of the structure of Snsl, which would improve our understanding of the molecular mechanism of cuticle formation and related pesticide resistance and provide a template for structure-based insecticide design.
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Chen J, Zou X, Zhu W, Duan Y, Merzendorfer H, Zhao Z, Yang Q. Fatty acid binding protein is required for chitin biosynthesis in the wing of Drosophila melanogaster. Insect Biochem Mol Biol 2022; 149:103845. [PMID: 36165873 DOI: 10.1016/j.ibmb.2022.103845] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 09/13/2022] [Accepted: 09/13/2022] [Indexed: 06/16/2023]
Abstract
Chitin, the major structural polysaccharide in arthropods such as insects and mites, is a linear polymer of N-acetylglucosamine units. The growth and development of insects are intimately coupled with chitin biosynthesis. The membrane-bound β-glycosyltransferase chitin synthase is known to catalyze the key polymerization step of N-acetylglucosamine. However, the additional proteins that might assist chitin synthase during chitin biosynthesis are not well understood. Recently, fatty acid binding protein (Fabp) has been suggested as a candidate that interacts with the chitin synthase Krotzkopf verkehrt (Kkv) in Drosophila melanogaster. Here, using split-ubiquitin membrane yeast two-hybrid and pull-down assays, we have demonstrated that the Fabp-B splice variant physically interacts with Kkv in vitro. The global knockdown of Fabp in D. melanogaster using RNA interference (RNAi) induced lethality at the larval stage. Moreover, in tissue-specific RNAi experiments, silenced Fabp expression in the epidermis and tracheal system caused a lethal larval phenotype. Fabp knockdown in the wings resulted in an abnormal wing development and uneven cuticular surface. In addition to reducing the chitin content in the first longitudinal vein of wings, Fabp silencing also caused the loss of procuticle laminate structures. This study revealed that Fabp plays an important role in chitin synthesis and contributes to a comprehensive understanding of the complex insect chitin biosynthesis.
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Affiliation(s)
- Jiqiang Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Beijing, 100193, China; Department of Entomology, MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Xu Zou
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Beijing, 100193, China
| | - Weixing Zhu
- School of Bioengineering, Dalian University of Technology, No. 2, Linggong Road, Dalian, 116024, China
| | - Yanwei Duan
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, No 7 Pengfei Road, Shenzhen, 518120, China
| | - Hans Merzendorfer
- Institute of Biology, University of Siegen, Adolf-Reichwein-Strasse 2, Siegen, 57068, Germany
| | - Zhangwu Zhao
- Department of Entomology, MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China.
| | - Qing Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Beijing, 100193, China; School of Bioengineering, Dalian University of Technology, No. 2, Linggong Road, Dalian, 116024, China; Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, No 7 Pengfei Road, Shenzhen, 518120, China.
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Sirasoonthorn P, Kamiya K, Miura K. Antifungal roles of adult-specific cuticular protein genes of the red flour beetle, Tribolium castaneum. J Invertebr Pathol 2021; 186:107674. [PMID: 34606828 DOI: 10.1016/j.jip.2021.107674] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 09/11/2021] [Accepted: 09/25/2021] [Indexed: 11/20/2022]
Abstract
The insect cuticle is a composite structure that can further be divided into a few sub-structural layers. Its large moiety comprises a lattice of chitin fibrils and structural proteins, both of which are stabilized by covalent bonding among them. The cuticle covers the whole surface of insect body, and thus has long been suggested for the involvement in defense against entomopathogens, especially entomopathogenic fungi that infect percutaneously. We have been addressing this issue in the past few years and have so far demonstrated experimentally that chitin synthase 1, laccase2 as well as benzoquinone synthesis-related genes of Tribolium castaneum have indispensable roles in the antifungal host defense. In the present study we focused on another major component of the insect cuticular integument, structural cuticular proteins. We chose three genes coding for adult-specific cuticular proteins, namely CPR4, CPR18 and CPR27, and examined their roles in forming immunologically sound adult cuticular integuments. Analyses of developmental expression revealed that the three genes showed high level expression in the pupal stage. These results are consistent with their proposed roles in constructing cuticle of adult beetles. The RNA interference-mediated gene knockdown was employed to silence these genes, and the administration of double strand RNAs in pupae resulted in the adults with malformed elytra. The single knockdown of the three genes attenuated somewhat the defense of the resulting adult beetles against Beauveria bassiana and Metarhizium anisopliae, but statistical analyses indicated no significant differences from controls. In contrast, the double or triple knockdown mutant beetles displayed a drastic disruption of the host defense against the two entomopathogenic fungal species irrespective of the combination of targeted cuticular protein genes, demonstrating the important roles of the three cuticular protein genes in conferring robust antifungal properties on the adult cuticle. Scanning electron microscopic observation revealed that the germination of conidia attached on the adult body surface was still suppressed after the gene knockdown as in the case of wild-type beetles, suggesting that the weakened antifungal phenotypes resulted from the combined knockdown of the adult-specific cuticular protein genes could not be accounted for by the disfunction of secretion/retention of fungistatic benzoquinone derivatives.
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Affiliation(s)
- Patchara Sirasoonthorn
- Applied Entomology Laboratory, Department of Animal Sciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-Cho, Chikusa, Nagoya 464-8601, Japan
| | - Katsumi Kamiya
- Applied Entomology Laboratory, Department of Animal Sciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-Cho, Chikusa, Nagoya 464-8601, Japan
| | - Ken Miura
- Applied Entomology Laboratory, Department of Animal Sciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-Cho, Chikusa, Nagoya 464-8601, Japan.
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Awater-Salendo S, Voigt D, Hilker M, Fürstenau B. Cuticular Hydrocarbon Trails Released by Host Larvae Lose their Kairomonal Activity for Parasitoids by Solidification. J Chem Ecol 2021; 47:998-1013. [PMID: 34529198 PMCID: PMC8642257 DOI: 10.1007/s10886-021-01310-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/21/2021] [Accepted: 08/26/2021] [Indexed: 11/29/2022]
Abstract
Successful host search by parasitic wasps is often mediated by host-associated chemical cues. The ectoparasitoid Holepyris sylvanidis is known to follow chemical trails released by host larvae of the confused flour beetle, Tribolium confusum, for short-range host location. Although the hexane-extractable trails consist of stable, long-chain cuticular hydrocarbons (CHCs) with low volatility, the kairomonal activity of a trail is lost two days after release. Here, we studied whether this loss of kairomonal activity is due to changes in the chemical trail composition induced by microbial activity. We chemically analyzed trails consisting of hexane extracts of T. confusum larvae after different time intervals past deposition under sterile and non-sterile conditions. GC-MS analyses revealed that the qualitative and quantitative pattern of the long-chain CHCs of larval trails did not significantly change over time, neither under non-sterile nor sterile conditions. Hence, our results show that the loss of kairomonal activity of host trails is not due to microbially induced changes of the CHC pattern of a trail. Interestingly, the kairomonal activity of trails consisting of host larval CHC extracts was recoverable after two days by applying hexane to them. After hexane evaporation, the parasitoids followed the reactivated host trails as they followed freshly laid ones. Cryo-scanning electron microscopy showed that the trails gradually formed filament-shaped microstructures within two days. This self-assemblage of CHCs was reversible by hexane application. Our study suggests that the long-chain CHCs of a host trail slowly undergo solidification by a self-assembling process, which reduces the accessibility of CHCs to the parasitoid’s receptors as such that the trail is no longer eliciting trail-following behavior.
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Affiliation(s)
- Sarah Awater-Salendo
- Federal Research Centre for Cultivated Plants, Institute for Ecological Chemistry, Plant Analysis and Stored Product Protection, Julius Kühn Institute, Königin-Luise-Str.19, 14195, Berlin, Germany.,Dahlem Centre of Plant Science, Institute of Biology, Applied Zoology/Animal Ecology, Freie Universität Berlin, Haderslebener Str.9, 12163, Berlin, Germany
| | - Dagmar Voigt
- Institute of Botany, Faculty of Biology, Technische Universität Dresden, Zellescher Weg 20b, 01217, Dresden, Germany
| | - Monika Hilker
- Dahlem Centre of Plant Science, Institute of Biology, Applied Zoology/Animal Ecology, Freie Universität Berlin, Haderslebener Str.9, 12163, Berlin, Germany
| | - Benjamin Fürstenau
- Federal Research Centre for Cultivated Plants, Institute for Ecological Chemistry, Plant Analysis and Stored Product Protection, Julius Kühn Institute, Königin-Luise-Str.19, 14195, Berlin, Germany.
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Li C, Gorb SN, Rajabi H. Cuticle sclerotization determines the difference between the elastic moduli of locust tibiae. Acta Biomater 2020; 103:189-195. [PMID: 31843719 DOI: 10.1016/j.actbio.2019.12.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 12/09/2019] [Accepted: 12/10/2019] [Indexed: 11/29/2022]
Abstract
A striking characteristic of insect cuticle is the wide range of its material property values, with respect to stiffness, strength and toughness. The elastic modulus of cuticle, for instance, ranges over seven orders of magnitude in different structures and different species. Previous studies suggested that this characteristic is influenced by the microstructure and sclerotization of cuticle. However, the relative role of the two factors in determining the material properties of cuticle is unknown. Here we used a combination of scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and nanoindentation, to investigate the effect of microstructure and sclerotization on the elastic modulus of tibiae of desert locusts. Our results showed that tibial cuticle is an anisotropic material with the highest elastic modulus along the tibial axis. This is likely because majority of the fibers in the cuticle are oriented along this axis. We also found that the hind tibia has a significantly higher elastic modulus, compared with the fore and mid tibiae. This is likely due to the higher sclerotization level of the hind tibia cuticle, and seems to be an adaptation to the locust locomotion by jumping, in which axial loads in the hind tibiae may reach several times the insect body weight. Our results suggest that while sclerotization determines the difference between the elastic moduli of the tibiae, anisotropic properties of each tibia is controlled by the specific fiber orientation. Our study provides one of only a few comprehensive investigations on insect cuticle, and helps to better understand the structure-material-function relationship in this complex biological composite. STATEMENT OF SIGNIFICANCE: Insect cuticle is a biological composite with strong anisotropy and wide ranges of material properties. Using an example of the tibial cuticle of desert locusts, we examined the role of two influential factors on the elastic modulus of cuticle: microstructure and sclerotization. Our results suggested the strong influence of sclerotization on the variation of the elastic modulus among fore, mid and hind tibiae, and that of the microstructure on the anisotropy of each tibia. Our results deepens the current understanding of the structure-material-function relationship in complex insect cuticle.
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Affiliation(s)
- Chuchu Li
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Kiel, Germany.
| | - Stanislav N Gorb
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Kiel, Germany
| | - Hamed Rajabi
- Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Kiel, Germany
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Ma Y, Wan C, Gorb S, Rajabi H. Biomechanics of fore wing to hind wing coupling in the southern green stink bug Nezara viridula (Pentatomidae). Acta Biomater 2019; 100:10-17. [PMID: 31542500 DOI: 10.1016/j.actbio.2019.09.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 09/16/2019] [Accepted: 09/17/2019] [Indexed: 10/26/2022]
Abstract
Stink bugs have wing coupling mechanisms to synchronize flapping of their wings. The wing coupling is performed through a clamp-like structure on the fore wing (i.e. hemelytron) and a rolled margin on the hind wing. Here we used modern imaging techniques to investigate structural characteristics and material composition of the wing coupling of the stink bug Nezara viridula. We found that the surfaces of the clamp-like structure and the rolled margin are covered by highly-sclerotized microtrichia, which are expected to reduce friction between the wings during flapping flight. Micro-force measurements showed that fore and hind wings can be coupled only in certain angles ranging from 40.6° to 267.7° The results further showed that the force required to uncouple fore and hind wings is maximal for a range of angles which they make with each other during flight (127.1°-238.9°). In contrast to previous observations on some other insect species, the removal of the wing coupling in stink bugs led to complete loss of flight ability. In summary, we concluded that the shape, material composition and orientation of the coupling structure guarantee a robust fore wing to hind wing coupling during flight and a fast, easy uncoupling at rest. STATEMENT OF SIGNIFICANCE: Although the coupling mechanism of insect fore wing and hind wing has long been described, the functionality of this mechanism still remains largely unknown. In the present work, using a combination of modern imaging techniques and mechanical testing, we studied the functional morphology of the fore wing-hind wing coupling mechanism of the stink bug Nezara viridula. Our study reveals the crucial role of the mechanism in the flight ability of the stink bug and sheds light on the structure-property-function relationships of the functional diptery in insects.
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Tan G, Kaya M, Tevlek A, Sargin I, Baran T. Antitumor activity of chitosan from mayfly with comparison to commercially available low, medium and high molecular weight chitosans. In Vitro Cell Dev Biol Anim 2018; 54:366-374. [PMID: 29654403 DOI: 10.1007/s11626-018-0244-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 03/15/2018] [Indexed: 11/29/2022]
Abstract
Insects' cuticles have a potential to be evaluated as a chitin source. Especially adults of aquatic insects like mayflies (order Ephemeroptera) swarm in enormous numbers in artificially lit areas while mating in spring and then die by leaving huge amounts of dead insects' bodies. Here in this study, mayfly corpses were harvested and used for production of low MW chitosan. Dried mayfly bodies had 10.21% chitin content; mayfly chitin was converted into chitosan with efficiency rate of 78.43% (deacetylation degree, 84.3%; MW, 3.69 kDa). Cytotoxicity and anti-proliferative activity of mayfly and commercially available shrimp chitosans (low, medium, and high MW) were determined on L929 fibroblast and three different cancer types including HeLa, A549, and WiDr. Apoptosis and necrosis stimulating potential of mayfly and commercial chitosans were also evaluated on A549 and WiDr cells using acridine orange and propidium iodide dual staining to observe morphological changes in nuclei and thus to reveal the predominant cell death mechanism. The effects of chitosans have varied depending on cell types, concentration, and chitosan derivatives. Mayfly and low MW chitosans had a cytotoxic effect at a concentration of 500 μg mL-1 on non-cancer cells. At concentrations below this value (250 μg mL-1), mayfly and commercial chitosans except high MW one exhibited strong inhibitory activity on cancer cells especially A549 and WiDr cells. Mayfly chitosan induced early and late apoptosis in A549 cells, but late apoptosis and necrosis in WiDr cells. This study suggests that dead bodies of mayflies can be used for production of low MW chitosan with anti-proliferative activity.
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Affiliation(s)
- G Tan
- Department of Biology, Faculty of Science and Letters, Aksaray University, TR-68100, Aksaray, Turkey.
| | - M Kaya
- Department of Biotechnology and Molecular Biology, Faculty of Science and Letters, Aksaray University, TR-68100, Aksaray, Turkey
| | - A Tevlek
- Bioengineering Division, Institute of Science and Engineering, Hacettepe University, TR-06800, Ankara, Turkey
| | - I Sargin
- Department of Biotechnology and Molecular Biology, Faculty of Science and Letters, Aksaray University, TR-68100, Aksaray, Turkey
| | - T Baran
- Department of Chemistry, Faculty of Science and Letters, Aksaray University, TR-68100, Aksaray, Turkey
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Aberle B, Jemmali R, Dirks JH. Effect of sample treatment on biomechanical properties of insect cuticle. Arthropod Struct Dev 2017; 46:138-146. [PMID: 27495946 DOI: 10.1016/j.asd.2016.08.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 07/13/2016] [Accepted: 08/01/2016] [Indexed: 06/06/2023]
Abstract
Experimental limitations often prevent to perform biomechanical measurements on fresh arthropod cuticle samples. Hence, in many cases short- or long-term storage of samples is required. So far, it is not known whether any of the standard lab-techniques commonly used to fix or store insect cuticle samples in any way affects the biomechanical properties of the respective samples. In this paper we systematically address this question for the first time, with a focus on practical, easily accessible and common lab-methods including storage in water, ethanol, glutaraldehyde, freezing and desiccation. We performed a comprehensive and sensitive non-destructive Dynamic Mechanical Analysis (DMA) on locust hind leg tibiae using a three-point-bending setup. Our results show that from all tested treatments, freezing samples at -20 °C was the best option to maintain the original values for Young's modulus and damping properties of insect cuticle. In addition, our results indicate that the damping properties of locust hind legs might be mechanically optimized in respect to the jumping and kicking direction.
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Affiliation(s)
- Benjamin Aberle
- Dept. New Materials and Biosystems, Max-Planck-Institute for Intelligent Systems, Heisenbergstr. 3, 70563 Stuttgart, Germany
| | - Raouf Jemmali
- Institute of Structures and Design, German Aerospace Center (DLR), Pfaffenwaldring 38-40, 70569 Stuttgart, Germany
| | - Jan-Henning Dirks
- Dept. New Materials and Biosystems, Max-Planck-Institute for Intelligent Systems, Heisenbergstr. 3, 70563 Stuttgart, Germany.
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Hayakawa Y, Kato D, Kamiya K, Minakuchi C, Miura K. Chitin synthase 1 gene is crucial to antifungal host defense of the model beetle, Tribolium castaneum. J Invertebr Pathol 2016; 143:26-34. [PMID: 27867018 DOI: 10.1016/j.jip.2016.11.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Revised: 11/14/2016] [Accepted: 11/16/2016] [Indexed: 01/07/2023]
Abstract
The importance of the insect cuticle as a primary protective barrier against entomopathogens has long been noted. In the present study, we addressed this issue by utilizing an experimental infection system composed of the model beetle T. castaneum and two entomopathogenic fungal species, Beauveria bassiana and Metarhizium anisopliae. The pupae were relatively susceptible to these fungi by the natural route of infection, with some refractoriness developed with age, while the adults exhibited much higher refractoriness. Whereas M. anisopliae exhibited seemingly higher infectivity to the pupae compared to B. bassiana when the natural conidium infection was employed, direct inoculation of cultured hyphal body cells into the hemocoel was found highly and equally virulent in the pupae for the both fungal species. These results collectively suggest an important role of the cuticular integument in antifungal host defense, and we subsequently conducted the knockdown of chitin synthase 1 gene (CHS1). We targeted the prepupal and mid-pupal peaks of its expression respectively by using injection of the dsRNA at very low dosages to avoid lethality. The resulting pupae looked normal, but the adults showed a mild phenotype with dimpled/wrinkled elytra. The CHS1 gene knockdown compromised significantly host defense against the fungal infection via the natural route, except the configuration of knockdown pupae and M. anisopliae, suggesting an indispensable role of CHS1.
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Affiliation(s)
- Yuuki Hayakawa
- Applied Entomology Laboratory, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan
| | - Daiki Kato
- Applied Entomology Laboratory, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan
| | - Katsumi Kamiya
- Applied Entomology Laboratory, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan
| | - Chieka Minakuchi
- Applied Entomology Laboratory, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan
| | - Ken Miura
- Applied Entomology Laboratory, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan.
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Gottardo M, Vallotto D, Beutel RG. Giant stick insects reveal unique ontogenetic changes in biological attachment devices. Arthropod Struct Dev 2015; 44:195-199. [PMID: 25601633 DOI: 10.1016/j.asd.2015.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 01/08/2015] [Accepted: 01/08/2015] [Indexed: 06/04/2023]
Abstract
A strong modification of tarsal and pretarsal attachment pads during the postembryonic development is described for the first time. In the exceptionally large thorny devil stick insect Eurycantha calcarata a functional arolium is only present in the immature instars, enabling them to climb on smooth surfaces, especially leaves. Nymphs are also characterized by greyish and hairy euplantulae on tarsomeres 1-4. The gradual modifications of the arolium and the euplantula of tarsomere 5 in the nymphal development are probably mainly related to increased weight. The distinct switch in the life style between the leaf-dwelling nymphal stages and the ground-dwelling adults results in the final abrupt change of the adhesive devices, resulting in a far-reaching reduction of the arolium, the presence of a fully-developed, elongated euplantula on tarsomere 5, and white and smooth euplantulae on tarsomeres 1-4. The developmental remodelling of attachment pads also reflects a phylogenetic pattern. The attachment devices of the earlier instars are similar to those found in the basalmost lineage of extant stick insects, Timema, which is characterized by a very large pan-shaped arolium and a hairy surface of the tarsal and pretarsal attachment pads.
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Affiliation(s)
- Marco Gottardo
- Department of Life Sciences, University of Siena, Via A. Moro 4, 53100 Siena, Italy.
| | | | - Rolf G Beutel
- Institut für Spezielle Zoologie und Evolutionsbiologie mit Phyletischem Museum, Friedrich-Schiller-Universität Jena, Ebertstrasse 1, D-07743 Jena, Germany
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