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Li Z, Chen X, Zhao F, Miao M. Genomic insights into the cellular specialization of predation in raptorial protists. BMC Biol 2024; 22:107. [PMID: 38715037 PMCID: PMC11077807 DOI: 10.1186/s12915-024-01904-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 04/26/2024] [Indexed: 05/12/2024] Open
Abstract
BACKGROUND Predation is a fundamental mechanism for organisms to acquire energy, and various species have evolved diverse tools to enhance their hunting abilities. Among protozoan predators, raptorial Haptorian ciliates are particularly fascinating as they possess offensive extrusomes known as toxicysts, which are rapidly discharged upon prey contact. However, our understanding of the genetic processes and specific toxins involved in toxicyst formation and discharge is still limited. RESULTS In this study, we investigated the predation strategies and subcellular structures of seven Haptoria ciliate species and obtained their genome sequences using single-cell sequencing technology. Comparative genomic analysis revealed distinct gene duplications related to membrane transport proteins and hydrolytic enzymes in Haptoria, which play a crucial role in the production and discharge of toxicysts. Transcriptomic analysis further confirmed the abundant expression of genes related to membrane transporters and cellular toxins in Haptoria compared to Trichostomatia. Notably, polyketide synthases (PKS) and L-amino acid oxidases (LAAO) were identified as potentially toxin genes that underwent extensive duplication events in Haptoria. CONCLUSIONS Our results shed light on the evolutionary and genomic adaptations of Haptorian ciliates for their predation strategies in evolution and provide insights into their toxic mechanisms.
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Affiliation(s)
- Zaihan Li
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiao Chen
- Laboratory of Marine Protozoan Biodiversity and Evolution, Marine College, Shandong University, Weihai, 264209, China
| | - Fangqing Zhao
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Institute of Zoology, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China
| | - Miao Miao
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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2
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Barrionuevo JS, Pucci Alcaide F. Back to the water: Tongue morphology associated to contrasting lifestyles in two Andean frogs of the genus Telmatobius. ZOOLOGY 2024; 163:126157. [PMID: 38428124 DOI: 10.1016/j.zool.2024.126157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 02/05/2024] [Accepted: 02/17/2024] [Indexed: 03/03/2024]
Abstract
The evolution of the tongue in tetrapods is associated with feeding in the terrestrial environment. This study analyzes the tongue morphology of two closely related frog species, Telmatobius oxycephalus and T. rubigo, which exhibit contrasting feeding mechanisms. Telmatobius oxycephalus, a semi-aquatic species, relies on its tongue to capture terrestrial prey whereas T. rubigo, a secondarily aquatic species, uses suction feeding not involving the tongue. Through anatomical, histological and scanning electron microscopy analyses, we revealed remarkable differences in tongue morphology between these species. Telmatobius oxycephalus exhibits a well-developed tongue whose dorsal epithelium has numerous and slender filiform papillae. The epithelial cells of the papillae are protruded and have a complex array of microridges. In contrast, T. rubigo possesses a reduced tongue with flat and less numerous filiform papillae. The epithelial cells are completely flat and lack microridges. These findings highlight the remarkable adaptability of lingual morphology in Telmatobius to respond to the contrasting ecological niches and prey capture mechanisms. This study sheds light on the relationship between tongue shape and the different functional demands, contributing to our understanding of the evolution of prey capture mechanisms in amphibians.
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Affiliation(s)
- J Sebastián Barrionuevo
- Área Herpetología, Unidad Ejecutora Lillo (CONICET-Fundación Miguel Lillo), Miguel Lillo 251, S. M. de Tucumán, Argentina; Fundación Miguel Lillo, Miguel Lillo 251, S. M. de Tucumán, Argentina.
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3
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Bels V, Le Floch G, Kirchhoff F, Gastebois G, Davenport J, Baguette M. Food transport in Reptilia: a comparative viewpoint. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220542. [PMID: 37839442 PMCID: PMC10577028 DOI: 10.1098/rstb.2022.0542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 07/19/2023] [Indexed: 10/17/2023] Open
Abstract
Reptilia exploit a large diversity of food resources from plant materials to living mobile prey. They are among the first tetrapods that needed to drink to maintain their water homeostasis. Here were compare the feeding and drinking mechanisms in Reptilia through an empirical approach based on the available data to open perspectives in our understanding of the evolution of the various mechanisms determined in these Tetrapoda for exploiting solid and liquid food resources. This article is part of the theme issue 'Food processing and nutritional assimilation in animals'.
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Affiliation(s)
- Vincent Bels
- Institut Systématique, Evolution, et Biodiversité (ISYEB), UMR 7205 Museum d'Histoire Naturelle (MNHN), CNRS, Sorbonne Université, EPHE, Université des Antilles, 75005 Paris, France
| | - Glenn Le Floch
- Institut Systématique, Evolution, et Biodiversité (ISYEB), UMR 7205 Museum d'Histoire Naturelle (MNHN), CNRS, Sorbonne Université, EPHE, Université des Antilles, 75005 Paris, France
| | - Florence Kirchhoff
- Institut Systématique, Evolution, et Biodiversité (ISYEB), UMR 7205 Museum d'Histoire Naturelle (MNHN), CNRS, Sorbonne Université, EPHE, Université des Antilles, 75005 Paris, France
| | | | - John Davenport
- School of Biological, Earth and Environmental Sciences, Distillery Fields, North Mall, University College Cork, Ireland T23 N73K
| | - Michel Baguette
- Institut Systématique, Evolution, et Biodiversité (ISYEB), UMR 7205 Museum d'Histoire Naturelle (MNHN), CNRS, Sorbonne Université, EPHE, Université des Antilles, 75005 Paris, France
- Station d'Ecologie Théorique et Expérimentale, CNRS UAR 2029, Route du CNRS, F-09200 Moulis, France
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4
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Krings W, Gorb SN. Particle binding capacity of snail saliva. J Chem Phys 2023; 159:185101. [PMID: 37955324 DOI: 10.1063/5.0176668] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 10/20/2023] [Indexed: 11/14/2023] Open
Abstract
Gastropods forage with their radula, a thin chitinous membrane with embedded teeth, which scratch across the substrate to lose food particles. During this interaction, the risk of loosening particles is obvious without having a specialized mechanism holding them on the tooth surface. As mucus secretions are essential in molluscan life cycles and the locomotion and attachment gels are known to have an instant high adhesion, we have hypothesized that the saliva could support particle retention during feeding. As adhesion of snail saliva was not studied before, we present here an experimental setup to test its particle-binding capacity using a large land snail (Lissachatina fulica, Stylommatophora, Heterobranchia). This experiment was also applied to the gels produced by the snail foot for comparison and can be potentially applied to various fluids present at a small volume in the future. We found, that the saliva has high particle retention capacity that is comparable to the foot glue of the snail. To gain some insight into the properties of the saliva, we additionally studied it in the scanning electron microscope, estimated its viscosity in a de-wetting experiment, and investigated its elemental composition using energy dispersive X-ray spectroscopy reveling higher contents of Ca, Zn and other potential cross-linkers similar to those found in the glue.
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Affiliation(s)
- Wencke Krings
- Department of Cariology, Endodontology and Periodontology, Universität Leipzig, Liebigstraße 12, 04103 Leipzig, Germany
- Department of Electron Microscopy, Institute of Cell and Systems Biology of Animals, Universität Hamburg, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany
- Department of Mammalogy and Palaeoanthropology, Leibniz Institute for the Analysis of Biodiversity Change, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany
- Department of Functional Morphology and Biomechanics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, 24118 Kiel, Germany
| | - Stanislav N Gorb
- Department of Functional Morphology and Biomechanics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, 24118 Kiel, Germany
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Melrose J. High Performance Marine and Terrestrial Bioadhesives and the Biomedical Applications They Have Inspired. Molecules 2022; 27:molecules27248982. [PMID: 36558114 PMCID: PMC9783952 DOI: 10.3390/molecules27248982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/10/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
This study has reviewed the naturally occurring bioadhesives produced in marine and freshwater aqueous environments and in the mucinous exudates of some terrestrial animals which have remarkable properties providing adhesion under difficult environmental conditions. These bioadhesives have inspired the development of medical bioadhesives with impressive properties that provide an effective alternative to suturing surgical wounds improving closure and healing of wounds in technically demanding tissues such as the heart, lung and soft tissues like the brain and intestinal mucosa. The Gecko has developed a dry-adhesive system of exceptional performance and has inspired the development of new generation re-usable tapes applicable to many medical procedures. The silk of spider webs has been equally inspiring to structural engineers and materials scientists and has revealed innovative properties which have led to new generation technologies in photonics, phononics and micro-electronics in the development of wearable biosensors. Man made products designed to emulate the performance of these natural bioadhesive molecules are improving wound closure and healing of problematic lesions such as diabetic foot ulcers which are notoriously painful and have also found application in many other areas in biomedicine. Armed with information on the mechanistic properties of these impressive biomolecules major advances are expected in biomedicine, micro-electronics, photonics, materials science, artificial intelligence and robotics technology.
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Affiliation(s)
- James Melrose
- Raymond Purves Bone and Joint Research Laboratory, Kolling Institute, Faculty of Medicine and Health, University of Sydney at Royal North Shore Hospital, Northern Sydney Local Health District, St. Leonards, NSW 2065, Australia;
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia
- Sydney Medical School, Northern Campus, The University of Sydney, St. Leonards, NSW 2065, Australia
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Keeffe RM, Blob RW, Blackburn DC, Mayerl CJ. XROMM Analysis of Feeding Mechanics in Toads: Interactions of the Tongue, Hyoid, and Pectoral Girdle. Integr Org Biol 2022; 4:obac045. [PMCID: PMC9665897 DOI: 10.1093/iob/obac045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 10/04/2022] [Accepted: 10/20/2022] [Indexed: 10/17/2023] Open
Abstract
During feeding in many terrestrial vertebrates, the tongue acts in concert with the hyoid and pectoral girdle. In frogs, these three elements are interconnected by musculature. While the feeding mechanics of the anuran tongue are well-studied, little is known of how the motions of the tongue relate to the movements of the skeleton or how buccal structures move following closure of the mouth. Although features such as the pectoral girdle and hyoid are not externally visible in frogs, their motions can be tracked in X-ray video. We used XROMM (X-ray Reconstruction of Moving Morphology) techniques to track the 3D movements of the tongue, hyoid apparatus, pectoral girdle, skull, and jaw during the feeding cycle of the cane toad, Rhinella marina . We show how the movements of these elements are integrated during tongue protrusion and prey capture, as well as during prey transport, swallowing, and recovery. Our findings suggest that the hyoid apparatus is important both for prey manipulation and swallowing. The tongue consistently stretches posterior to the skull during swallowing, often more than it stretches during protrusion to reach the prey. Feeding kinematics are similar between individuals, and the kinematics of unsuccessful strikes generally resemble those of successful strikes. Our data also provide a new perspective on the potential role of the pectoral girdle, an element with a predominant locomotor function, during feeding events. This work raises new questions about the evolution of feeding in frogs, as well as how the diversity of pectoral and buccal anatomy observed across anurans may influence feeding kinematics.
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Affiliation(s)
- R M Keeffe
- Department of Biological Sciences, Mount Holyoke College, South Hadley, MA 01075, USA
| | - R W Blob
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA
| | - D C Blackburn
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
| | - C J Mayerl
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA
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7
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Choi JW, Kim GJ, Hong S, An JH, Kim BJ, Ha CW. Sequential process optimization for a digital light processing system to minimize trial and error. Sci Rep 2022; 12:13553. [PMID: 35941282 PMCID: PMC9360010 DOI: 10.1038/s41598-022-17841-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 08/02/2022] [Indexed: 11/09/2022] Open
Abstract
In additive manufacturing, logical and efficient workflow optimization enables successful production and reduces cost and time. These attempts are essential for preventing fabrication problems from various causes. However, quantitative analysis and integrated management studies of fabrication issues using a digital light processing (DLP) system are insufficient. Therefore, an efficient optimization method is required to apply several materials and extend the application of the DLP system. This study proposes a sequential process optimization (SPO) to manage the initial adhesion, recoating, and exposure energy. The photopolymerization characteristics and viscosity of the photocurable resin were quantitatively analyzed through process conditions such as build plate speed, layer thickness, and exposure time. The ability of the proposed SPO was confirmed by fabricating an evaluation model using a biocompatible resin. Furthermore, the biocompatibility of the developed resin was verified through experiments. The existing DLP process requires several trials and errors in process optimization. Therefore, the fabrication results are different depending on the operator's know-how. The use of the proposed SPO enables a systematic approach for optimizing the process conditions of a DLP system. As a result, the DLP system is expected to be more utilized.
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Affiliation(s)
- Jae Won Choi
- Advanced Joining and Additive Manufacturing R&D Department, Korea Institute of Industrial Technology, 113-58, Seohaean-ro, Siheung-si, 15014, Republic of Korea
- Department of Mechanical Engineering, BK21 FOUR ERICA-ACE Center, Hanyang University, 55 Hanyangdaehak-ro, Ansan, 15588, Republic of Korea
| | - Gyeong-Ji Kim
- Department of Food and Nutrition, KC University, 47, 24-Gil, Kkachisan-ro, Seoul, 07661, Republic of Korea
| | - Sukjoon Hong
- Department of Mechanical Engineering, BK21 FOUR ERICA-ACE Center, Hanyang University, 55 Hanyangdaehak-ro, Ansan, 15588, Republic of Korea
| | - Jeung Hee An
- Department of Food and Nutrition, KC University, 47, 24-Gil, Kkachisan-ro, Seoul, 07661, Republic of Korea
| | - Baek-Jin Kim
- Green Chemistry and Materials Group, Korea Institute of Industrial Technology, Daejeon, Chungcheongnam-do, 31056, Republic of Korea
- Department of Green Process and System Engineering, Korea University of Science and Technology (UST), Daejeon, Chungcheongnam-do, 31056, Republic of Korea
| | - Cheol Woo Ha
- Advanced Joining and Additive Manufacturing R&D Department, Korea Institute of Industrial Technology, 113-58, Seohaean-ro, Siheung-si, 15014, Republic of Korea.
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8
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Li J, Peng X, Ma C, Song Z, Liu J. Response mechanisms of snails to the pulling force and its potential application in vacuum suction. J Mech Behav Biomed Mater 2021; 124:104840. [PMID: 34537498 DOI: 10.1016/j.jmbbm.2021.104840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 09/08/2021] [Accepted: 09/11/2021] [Indexed: 11/17/2022]
Abstract
Snails offer successful attachment and locomotion on horizontal and vertical surfaces, and have inspired extensive research to develop artificial adhesives. Here, we experimentally investigate the response mechanisms of snails to mechanical signals (pull-off force and crawling angle), then propose a way to design a bioinspired sucker, and theoretically analysis its application in vacuum suction. The experimental results indicate that the pull-off force is 7 N, about 22 times of its weight, and relatively invariant across the angles of the substrate. The flexible body increases work consumption by stretching and deformation during pulling, and a cavity with negative pressure differential can exist at the interface to help resist the pulling. We extract the flexible body and formation of a negative pressure cavity at the contact interface as two key elements of the bioinspired sucker, and the analysis shows that it can be adaptable to an extend range of products compared with conventional vacuum suction, which illustrates the potential for industrial or robotic manipulation.
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Affiliation(s)
- Jing Li
- College of Mechanical and Electrical Engineering, China University of Petroleum (East China), Qingdao, 266580, China.
| | - Xianyu Peng
- College of Mechanical and Electrical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Chuandong Ma
- College of Mechanical and Electrical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Zhenzhen Song
- College of Mechanical and Electrical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Jianlin Liu
- College of Pipeline and Civil Engineering, China University of Petroleum (East China), Qingdao, 266580, China.
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Rühs PA, Bergfreund J, Bertsch P, Gstöhl SJ, Fischer P. Complex fluids in animal survival strategies. SOFT MATTER 2021; 17:3022-3036. [PMID: 33729256 DOI: 10.1039/d1sm00142f] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Animals have evolved distinctive survival strategies in response to constant selective pressure. In this review, we highlight how animals exploit flow phenomena by manipulating their habitat (exogenous) or by secreting (endogenous) complex fluids. Ubiquitous endogenous complex fluids such as mucus demonstrate rheological versatility and are therefore involved in many animal behavioral traits ranging from sexual reproduction to protection against predators. Exogenous complex fluids such as sand can be used either for movement or for predation. In all cases, time-dependent rheological properties of complex fluids are decisive for the fate of the biological behavior and vice versa. To exploit these rheological properties, it is essential that the animal is able to sense the rheology of their surrounding complex fluids in a timely fashion. As timing is key in nature, such rheological materials often have clearly defined action windows matching the time frame of their direct biological behavior. As many rheological properties of these biological materials remain poorly studied, we demonstrate with this review that rheology and material science might provide an interesting quantitative approach to study these biological materials in particular in context towards ethology and bio-mimicking material design.
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Affiliation(s)
- Patrick A Rühs
- Department of Bioengineering, University of California, 218 Hearst Memorial Mining Building, Berkeley, CA 94704, USA
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10
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The Oral Bacterial Community in Melanophryniscus admirabilis (Admirable Red-Belly Toads): Implications for Conservation. Microorganisms 2021; 9:microorganisms9020220. [PMID: 33499099 PMCID: PMC7912307 DOI: 10.3390/microorganisms9020220] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/11/2021] [Accepted: 01/18/2021] [Indexed: 12/14/2022] Open
Abstract
Melanophryniscus admirabilis (admirable red-belly toad) is a microendemic and critically endangered species found exclusively along 700 m of the Forqueta River, in a fragment of the Atlantic Forest of southern Brazil. One of the greatest concerns regarding the conservation of this species is the extensive use of pesticides in areas surrounding their natural habitat. In recent years, the adaptation and persistence of animal species in human-impacted environments have been associated with microbiota. Therefore, the present study aimed to characterize the oral bacterial community of wild M. admirabilis and to address the question of how this community might contribute to this toad’s adaptation in the anthropogenic environment as well as its general metabolic capabilities. A total of 11 oral samples collected from wild M. admirabilis were characterized and analyzed via high-throughput sequencing. Fragments of the 16S rRNA variable region 4 (V4) were amplified, and sequencing was conducted using an Ion Personal Genome Machine (PGM) System with 316 chips. A total of 181,350 sequences were obtained, resulting in 16 phyla, 34 classes, 39 orders, and 77 families. Proteobacteria dominated (53%) the oral microbiota of toads, followed by Firmicutes (18%), Bacteroidetes (17%), and Actinobacteria (5%). No significant differences in microbial community profile from among the samples were reported, which suggests that the low dietary diversity observed in this population may directly influence the bacterial composition. Inferences of microbiome function were performed using PICRUSt2 software. Important pathways (e.g., xenobiotic degradation pathways for pesticides and aromatic phenolic compounds) were detected, which suggests that the bacterial communities may serve important roles in M. admirabilis health and survival in the anthropogenic environment. Overall, our results have important implications for the conservation and management of this microendemic and critically endangered species.
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Zhai Z, Wang Y, Lin K, Wu L, Jiang H. In situ stiffness manipulation using elegant curved origami. SCIENCE ADVANCES 2020; 6:6/47/eabe2000. [PMID: 33208377 PMCID: PMC7673814 DOI: 10.1126/sciadv.abe2000] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 10/05/2020] [Indexed: 05/19/2023]
Abstract
The capability of stiffness manipulation for materials and structures is essential for tuning motion, saving energy, and delivering high power. However, high-efficiency in situ stiffness manipulation has not yet been successfully achieved despite many studies from different perspectives. Here, curved origami patterns were designed to accomplish in situ stiffness manipulation covering positive, zero, and negative stiffness by activating predefined creases on one curved origami pattern. This elegant design enables in situ stiffness switching in lightweight and space-saving applications, as demonstrated through three robotic-related components. Under a uniform load, the curved origami can provide universal gripping, controlled force transmissibility, and multistage stiffness response. This work illustrates an unexplored and unprecedented capability of curved origami, which opens new applications in robotics for this particular family of origami patterns.
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Affiliation(s)
- Zirui Zhai
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ 85287, USA
| | - Yong Wang
- Department of Engineering Mechanics, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Ken Lin
- Department of Engineering Mechanics, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Lingling Wu
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ 85287, USA
| | - Hanqing Jiang
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ 85287, USA.
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Sugiura S. Anti-predator defences of a bombardier beetle: is bombing essential for successful escape from frogs? PeerJ 2018; 6:e5942. [PMID: 30533294 PMCID: PMC6276596 DOI: 10.7717/peerj.5942] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 10/15/2018] [Indexed: 11/20/2022] Open
Abstract
Some animals, such as the bombardier beetles (Coleoptera: Carabidae: Brachinini), have evolved chemical defences against predators. When attacked, bombardier beetles can discharge noxious chemicals at temperatures of approximately 100 °C from the tip of their abdomens, "bombing" their attackers. Although many studies to date have investigated how bombardier beetles discharge defensive chemicals against predators, relatively little research has examined how predators modify their attacks on bombardier beetles to avoid being bombed. In this study, I observed the black-spotted pond frog Pelophylax nigromaculatus (Anura: Ranidae) attacking the bombardier beetle Pheropsophus jessoensis under laboratory conditions. In Japan, Pe. nigromaculatus is a generalist predator in grasslands where the bombardier beetle frequently occurs. Almost all the frogs (92.9%) observed rejected live bombardier beetles; 67.9% stopped their attacks once their tongues touched the beetles, and 25.0% spat out the beetles immediately after taking the beetles into their mouths. No beetle bombed a frog before being taken into a frog's mouth. All beetles taken into mouths bombed the frogs. Only 7.1% of the frogs swallowed live bombardier beetles after being bombed in the mouth. When dead beetles were provided instead, 85.7% of the frogs rejected the dead beetles, 71.4% stopped their attacks after their tongues touched the beetles, and 14.3% spat out the beetles. Only 14.3% of the frogs swallowed the dead beetles. The results suggest that the frogs tended to stop their predatory attack before receiving a bombing response from the beetles. Therefore, bombing was not essential for the beetles to successfully defend against the frogs. Using its tongue, Pe. nigromaculatus may be able to rapidly detect a deterrent chemical or physical characteristics of its potential prey Ph. jessoensis and thus avoid injury by stopping its predatory attack before the beetle bombs it.
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Affiliation(s)
- Shinji Sugiura
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
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Chaudhary G, Fudge DS, Macias-Rodriguez B, Ewoldt RH. Concentration-independent mechanics and structure of hagfish slime. Acta Biomater 2018; 79:123-134. [PMID: 30170194 DOI: 10.1016/j.actbio.2018.08.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 08/12/2018] [Accepted: 08/17/2018] [Indexed: 10/28/2022]
Abstract
The defense mechanism of hagfish slime is remarkable considering that hagfish cannot control the concentration of the resulting gel directly; they simply exude a concentrated material into a comparably "infinite" sea of water to form a dilute, sticky, cohesive elastic gel. This raises questions about the robustness of gel formation and rheological properties across a range of concentrations, which we study here for the first time. Across a nearly 100-fold change in concentration, we discover that the gel has similar viscoelastic time-dependent properties with constant power-law exponent (α=0.18±0.01), constant relative damping tanδ=G''/G'≈0.2-0.3, and varying overall stiffness that scales linearly with the concentration (∼c0.99±0.05). The power-law viscoelasticity (fit by a fractional Kelvin-Voigt model) is persistent at all concentrations with nearly constant fractal dimension. This is unlike other materials and suggests that the underlying material structure of slime remains self-similar irrespective of concentration. This interpretation is consistent with our microscopy studies of the fiber network. We derive a structure-rheology model to test the hypothesis that the origins of ultra-soft elasticity are based on bending of the fibers. The model predictions show an excellent agreement with the experiments. Our findings illustrate the unusual and robust properties of slime which may be vital in its physiological use and provide inspiration for the design of new engineered materials. STATEMENT OF SIGNIFICANCE Hagfish produce a unique gel-like material to defend themselves against predator attacks. The successful use of the defense gel is remarkable considering that hagfish cannot control the concentration of the resulting gel directly; they simply exude a small quantity of biomaterial which then expands by a factor of 10,000 (by volume) into an "infinite" sea of water. This raises questions about the robustness of gel formation and properties across a range of concentrations. This study provides the first ever understanding of the mechanics of hagfish slime over a very wide range of concentration. We discover that some viscoelastic properties of slime are remarkably constant regardless of its concentration. Such a characteristic is uncommon in most known materials.
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Abstract
ABSTRACT
Frogs, chameleons and anteaters are striking examples of animals that can grab food using only their tongue. How does the soft and wet surface of a tongue grip onto objects before they are ingested? Here, we review the diversity of tongue projection methods, tongue roughnesses and tongue coatings, our goal being to highlight conditions for effective grip and mobility. A softer tongue can reach farther: the frog Rana pipiens tongue is 10 times softer than the human tongue and can extend to 130% of its length when propelled in a whip-like motion. Roughness can improve a tongue's grip: the spikes on a penguin Eudyptes chrysolophus tongue can be as large as fingernails, and help the penguin swallow fish. The saliva coating on the tongue, a non-Newtonian biofluid, can either lubricate or adhere to food. Frog saliva is 175 times more viscous than human saliva, adhering the tongue to slippery, furry or feathery food. We pay particular attention to using mathematical models such as the theory of capillarity, elasticity and friction to elucidate the parameters for effective tongue use across a variety of vertebrate species. Finally, we postulate how the use of wet and rough surfaces to simultaneously sense and grip may inspire new strategies in emerging technologies such as soft robots.
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Affiliation(s)
- Alexis C. Noel
- The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - David L. Hu
- The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
- School of Biology, Georgia Institute of Technology, Atlanta, GA 30332, USA
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17
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Bhatia S, Singh P, Sharma P. Hodgkin-Huxley model based on ionic transport in axoplasmic fluid. J Integr Neurosci 2017; 16:401-417. [PMID: 28891525 DOI: 10.3233/jin-170029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Hodgkin-Huxley model has been reframed to incorporate the physical parameters of fluid inside the axon. The reframed model comprises of set of partial differential equations containing the physical parameters: density, mass fraction of sodium, potassium and chlorine ions, longitudinal diffusivity of ions and rate of additions of ions along with the temperature. Obtained conduction velocity of 19.5m/sec at a temperature of 18.5 degree celcius and conduction velocity dependency on temperature within the range 5 to 25 degree celcius are two important results that strongly validate the proposed model. The behavior of all the physical parameters has been characterized with respect to the action potential. Action potential conduction velocity along with axoplasmic fluid viscosity has been characterized with respect to different temperatures. Longitudinal diffusivity of ions is also quantified.
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Affiliation(s)
- Suman Bhatia
- Department of CSE&IT, The NorthCap University, Sec-23A Gurugram, 122017, India. E-mail:
| | - Phool Singh
- Department of Applied Sciences, The NorthCap University, Sec-23A Gurugram, 122017, India. E-mails: ,
| | - Prabha Sharma
- Department of Applied Sciences, The NorthCap University, Sec-23A Gurugram, 122017, India. E-mails: ,
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