1
|
Schertenleib KSH, Davey T, Taylor D, O'Connor NE. Key benthic species are affected by predicted warming in winter but show resistance to ocean acidification. Ecol Evol 2024; 14:e70308. [PMID: 39296734 PMCID: PMC11410397 DOI: 10.1002/ece3.70308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 08/10/2024] [Accepted: 08/31/2024] [Indexed: 09/21/2024] Open
Abstract
The effects of climate change on coastal biodiversity are a major concern because altered community compositions may change associated rates of ecosystem functioning and services. Whilst responses of single species or taxa have been studied extensively, it remains challenging to estimate responses to climate change across different levels of biological organisation. Studies that consider the effects of moderate realistic near-future levels of ocean warming and acidification are needed to identify and quantify the gradual responses of species to change. Also, studies including different levels of biological complexity may reveal opportunities for amelioration or facilitation under changing environmental conditions. To test experimentally for independent and combined effects of predicted near-future warming and acidification on key benthic species, we manipulated three levels of temperature (winter ambient, +0.8 and +2°C) and two levels of pco 2 (ambient at 450 ppm and elevated at 645 ppm) and quantified their effects on mussels and algae growing separately and together (to also test for inter-specific interactions). Warming increased mussel clearance and mortality rates simultaneously, which meant that total biomass peaked at +0.8°C. Surprisingly, however, no effects of elevated pco 2 were identified on mussels or algae. Moreover, when kept together, mussels and algae had mutually positive effects on each other's performance (i.e. mussel survival and condition index, mussel and algal biomass and proxies for algal productivity including relative maximum electron transport rate [rETRmax], saturating light intensity [I k] and maximum quantum yield [F v/F m]), independent of warming and acidification. Our results show that even moderate warming affected the functioning of key benthic species, and we identified a level of resistance to predicted ocean acidification. Importantly, we show that the presence of a second functional group enhanced the functioning of both groups (mussels and algae), independent of changing environmental conditions, which highlights the ecological and potential economic benefits of conserving biodiversity in marine ecosystems.
Collapse
Affiliation(s)
| | - Tallulah Davey
- Discipline of ZoologySchool of Natural Sciences, Trinity College DublinDublin 2Ireland
| | - David Taylor
- Department of Mechanical, Manufacturing and Biomedical EngineeringSchool of Engineering, Trinity College DublinDublin 2Ireland
| | - Nessa E. O'Connor
- Discipline of ZoologySchool of Natural Sciences, Trinity College DublinDublin 2Ireland
| |
Collapse
|
2
|
Newcomb LA, Cannistra AF, Carrington E. Divergent Effects of Ocean Warming On Byssal Attachment in Two Congener Mussel Species. Integr Comp Biol 2022; 62:icac111. [PMID: 35793561 DOI: 10.1093/icb/icac111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Organisms rely on the integrity of the structural materials they produce to maintain a broad range of processes, such as acquiring food, resisting predators or withstanding extreme environmental forces. The production and maintenance of these biomaterials, which are often modulated by environmental conditions, can therefore have important consequences for fitness in changing climates. One well-known example of such a biomaterial is mussel byssus, an array of collagen-like fibers (byssal threads) that tethers a bivalve mollusk securely to benthic marine substrates. Byssus strength directly influences mortality from dislodgement, predation or competition and depends on the quantity and quality of byssal threads produced. We compared the temperature sensitivity of byssal attachment strength of two mussel species common to the west coast of North America, Mytilus trossulus and M. galloprovincialis, when exposed to seawater temperatures ranging from 10 to 24˚C in the laboratory. We found the two species attached equally strong in seawater ≤ 18˚C, but higher temperatures caused byssal thread production rate and quality (break force and extensibility) to be greatly reduced in M. trossulus and increased in M. galloprovincialis, leading to a 2 to 10-fold difference in overall byssus strength between the two species. Using this threshold value (18˚C), we mapped habitat for each species along the west coast of North America based on annual patterns in sea surface temperature. Estimated ranges are consistent with the current distribution of the two species and suggest a potential mechanism by which ocean warming could facilitate the northern expansion of M. galloprovincialis and displacement of native M. trossulus populations.
Collapse
Affiliation(s)
- L A Newcomb
- Department of Biology, University of Washington, Seattle, Washington 98195, USA
- Friday Harbor Laboratories, University of Washington, 620 University Road, Friday Harbor, WA 98250, USA
| | - A F Cannistra
- Department of Biology, University of Washington, Seattle, Washington 98195, USA
| | - E Carrington
- Department of Biology, University of Washington, Seattle, Washington 98195, USA
- Friday Harbor Laboratories, University of Washington, 620 University Road, Friday Harbor, WA 98250, USA
| |
Collapse
|
3
|
Whaite A, Klein A, Mitu S, Wang T, Elizur A, Cummins S. The byssal-producing glands and proteins of the silverlip pearl oyster Pinctada maxima (Jameson, 1901). BIOFOULING 2022; 38:186-206. [PMID: 35282730 DOI: 10.1080/08927014.2022.2049256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 02/22/2022] [Accepted: 02/28/2022] [Indexed: 06/14/2023]
Abstract
Pinctada maxima are most well known for their production of high-quality natural pearls. They also generate another natural material, the byssus, an adhesive thread critical for steadfast attachment underwater. Herein, P. maxima byssal threads were analysed via proteotranscriptomics to reveal 49 proteins. Further characterisation was undertaken on five highly expressed genes: glycine-rich thread protein (GRT; also known as PUF3), apfp1/perlucin-like protein (Pmfp1); peroxidase; thrombospondin 1, and Balbiani ring 3 (BR3), which showed localised tissue expression. The spatial distribution of GRT and Pmfp1 via immunodetection combined with histology helped to identify glandular regions of the foot that contribute to byssal thread production: the byssal gland, the duct gland, and two thread-forming glands of basophilic and acidophilic serous-like cells. This work advanced primary knowledge on the glands involved in the creation of byssal threads and the protein composition of the byssus for P. maxima, providing a platform for the design of marine biopolymers.
Collapse
Affiliation(s)
- Alessandra Whaite
- Genecology Research Centre, University of the Sunshine Coast, Maroochydore DC, Queensland, Australia
- School of Science, Technology and Engineering, University of the Sunshine Coast, Maroochydore DC, Queensland, Australia
| | - Anne Klein
- Genecology Research Centre, University of the Sunshine Coast, Maroochydore DC, Queensland, Australia
- School of Science, Technology and Engineering, University of the Sunshine Coast, Maroochydore DC, Queensland, Australia
| | - Shahida Mitu
- Genecology Research Centre, University of the Sunshine Coast, Maroochydore DC, Queensland, Australia
- School of Science, Technology and Engineering, University of the Sunshine Coast, Maroochydore DC, Queensland, Australia
| | - Tianfang Wang
- Genecology Research Centre, University of the Sunshine Coast, Maroochydore DC, Queensland, Australia
- School of Science, Technology and Engineering, University of the Sunshine Coast, Maroochydore DC, Queensland, Australia
| | - Abigail Elizur
- Genecology Research Centre, University of the Sunshine Coast, Maroochydore DC, Queensland, Australia
| | - Scott Cummins
- Genecology Research Centre, University of the Sunshine Coast, Maroochydore DC, Queensland, Australia
- School of Science, Technology and Engineering, University of the Sunshine Coast, Maroochydore DC, Queensland, Australia
| |
Collapse
|
4
|
Marshall KE, Anderson KM, Brown NEM, Dytnerski JK, Flynn KL, Bernhardt JR, Konecny CA, Gurney-Smith H, Harley CDG. Whole-organism responses to constant temperatures do not predict responses to variable temperatures in the ecosystem engineer Mytilus trossulus. Proc Biol Sci 2021; 288:20202968. [PMID: 33757343 DOI: 10.1098/rspb.2020.2968] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Understanding and predicting responses of ectothermic animals to temperature are essential for decision-making and management. The thermal performance curve (TPC), which quantifies the thermal sensitivity of traits such as metabolism, growth and feeding rates in laboratory conditions, is often used to predict responses of wild populations. However, central assumptions of this approach are that TPCs are relatively static between populations and that curves measured under stable temperature conditions can predict performance under variable conditions. We test these assumptions using two latitudinally matched populations of the ecosystem engineer Mytilus trossulus that differ in their experienced temperature variability regime. We acclimated each population in a range of constant or fluctuating temperatures for six weeks and measured a series of both short term (feeding rate, byssal thread production) and long-term (growth, survival) metrics to test the hypothesis that performance in fluctuating temperatures can be predicted from constant temperatures. We find that this was not true for any metric, and that there were important interactions with the population of origin. Our results emphasize that responses to fluctuating conditions are still poorly understood and suggest caution must be taken in the use of TPCs generated under constant temperature conditions for the prediction of wild population responses.
Collapse
Affiliation(s)
- Katie E Marshall
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kathryn M Anderson
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Norah E M Brown
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada.,Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
| | - James K Dytnerski
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Kelsey L Flynn
- Fisheries and Oceans Canada, Aquatic Diagnostics, Genomics & Technology, Nanaimo, British Columbia, Canada
| | - Joey R Bernhardt
- Department of Ecology and Evolutionary Biology, Yale University, CT, USA
| | - Cassandra A Konecny
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Helen Gurney-Smith
- Coastal Ecosystems Science Division, Fisheries and Oceans Canada, Biological Effects Section, St Andrews, New Brunswick, Canada.,Hakai Institute, Heriot Bay Road, Quadra Island, British Columbia, Canada
| | - Christopher D G Harley
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada.,Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, British Columbia, Canada.,Hakai Institute, Heriot Bay Road, Quadra Island, British Columbia, Canada
| |
Collapse
|
5
|
Benthotage C, Cole VJ, Schulz KG, Benkendorff K. A review of the biology of the genus Isognomon (Bivalvia; Pteriidae) with a discussion on shellfish reef restoration potential of Isognomon ephippium. MOLLUSCAN RESEARCH 2020. [DOI: 10.1080/13235818.2020.1837054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Chamara Benthotage
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, East Lismore, Australia
| | - Victoria J. Cole
- Department of Primary Industries Fisheries, Port Stephens Fisheries Institute, Taylors Beach, Australia
| | - Kai G. Schulz
- Centre for Coastal Biogeochemistry, Southern Cross University, East Lismore, Australia
| | - Kirsten Benkendorff
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, East Lismore, Australia
- National Marine Science Centre, School of Environment, Science and Engineering, Southern Cross University, Coffs Harbour, Australia
| |
Collapse
|
6
|
Wang C, Zhang S, Zhang L, Xu Y, Zhang L. Evading the strength–ductility trade-off dilemma of rigid thermosets by incorporating triple cross-links of varying strengths. Polym Chem 2020. [DOI: 10.1039/d0py00928h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new class of rigid thermosets with simultaneously enhanced strengths and ductilities have been successfully designed and synthesised.
Collapse
Affiliation(s)
- Cheng Wang
- Research Center of Laser Fusion
- China Academy of Engineering Physics
- Mianyang
- P. R. China
| | - Shuai Zhang
- Research Center of Laser Fusion
- China Academy of Engineering Physics
- Mianyang
- P. R. China
| | - Longfei Zhang
- Research Center of Laser Fusion
- China Academy of Engineering Physics
- Mianyang
- P. R. China
- State Key Laboratory of Environment-friendly Energy Materials & School of Material Science and Engineering & National Engineering Technology Center for Insulation Materials
| | - Yewei Xu
- State Key Laboratory of Environment-friendly Energy Materials & School of Material Science and Engineering & National Engineering Technology Center for Insulation Materials
- Southwest University of Science and Technology
- Mianyang
- P. R. China
| | - Lin Zhang
- Research Center of Laser Fusion
- China Academy of Engineering Physics
- Mianyang
- P. R. China
| |
Collapse
|
7
|
Pasche D, Horbelt N, Marin F, Motreuil S, Fratzl P, Harrington MJ. Self-healing silk from the sea: role of helical hierarchical structure in Pinna nobilis byssus mechanics. SOFT MATTER 2019; 15:9654-9664. [PMID: 31720677 DOI: 10.1039/c9sm01830a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The byssus fibers of Mytilus mussel species have become an important role model in bioinspired materials research due to their impressive properties (e.g. high toughness, self-healing); however, Mytilids represent only a small subset of all byssus-producing bivalves. Recent studies have revealed that byssus from other species possess completely different protein composition and hierarchical structure. In this regard, Pinna nobilis byssus is especially interesting due to its very different morphology, function and its historical use for weaving lightweight golden fabrics, known as sea silk. P. nobilis byssus was recently discovered to be comprised of globular proteins organized into a helical protein superstructure. In this work, we investigate the relationships between this hierarchical structure and the mechanical properties of P. nobilis byssus threads, including energy dissipation and self-healing capacity. To achieve this, we performed in-depth mechanical characterization, as well as tensile testing coupled with in situ X-ray scattering. Our findings reveal that P. nobilis byssus, like Mytilus, possesses self-healing and energy damping behavior and that the initial elastic behavior of P. nobilis byssus is due to stretching and unraveling of the previously observed helical building blocks comprising the byssus. These findings have biological relevance for understanding the convergent evolution of mussel byssus for different species, and also for the field of bio-inspired materials.
Collapse
Affiliation(s)
- Delphine Pasche
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam 14424, Germany
| | - Nils Horbelt
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam 14424, Germany
| | - Frédéric Marin
- UMR CNRS 6282 Biogéosciences, Université de Bourgogne - Franche-Comté, Dijon 21000, France
| | - Sébastien Motreuil
- UMR CNRS 6282 Biogéosciences, Université de Bourgogne - Franche-Comté, Dijon 21000, France
| | - Peter Fratzl
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam 14424, Germany
| | - Matthew J Harrington
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam 14424, Germany and Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada.
| |
Collapse
|
8
|
Zechel S, Hager MD, Priemel T, Harrington MJ. Healing through Histidine: Bioinspired Pathways to Self-Healing Polymers via Imidazole⁻Metal Coordination. Biomimetics (Basel) 2019; 4:E20. [PMID: 31105205 PMCID: PMC6477608 DOI: 10.3390/biomimetics4010020] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 02/19/2019] [Accepted: 02/22/2019] [Indexed: 12/03/2022] Open
Abstract
Biology offers a valuable inspiration toward the development of self-healing engineering composites and polymers. In particular, chemical level design principles extracted from proteinaceous biopolymers, especially the mussel byssus, provide inspiration for design of autonomous and intrinsic healing in synthetic polymers. The mussel byssus is an acellular tissue comprised of extremely tough protein-based fibers, produced by mussels to secure attachment on rocky surfaces. Threads exhibit self-healing response following an apparent plastic yield event, recovering initial material properties in a time-dependent fashion. Recent biochemical analysis of the structure-function relationships defining this response reveal a key role of sacrificial cross-links based on metal coordination bonds between Zn2+ ions and histidine amino acid residues. Inspired by this example, many research groups have developed self-healing polymeric materials based on histidine (imidazole)-metal chemistry. In this review, we provide a detailed overview of the current understanding of the self-healing mechanism in byssal threads, and an overview of the current state of the art in histidine- and imidazole-based synthetic polymers.
Collapse
Affiliation(s)
- Stefan Zechel
- Laboratory for Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstr. 10, 07743 Jena, Germany.
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany.
| | - Martin D Hager
- Laboratory for Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstr. 10, 07743 Jena, Germany.
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany.
| | - Tobias Priemel
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, QC H3A 0B8, Canada.
| | - Matthew J Harrington
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, QC H3A 0B8, Canada.
| |
Collapse
|
9
|
George MN, Pedigo B, Carrington E. Hypoxia weakens mussel attachment by interrupting DOPA cross-linking during adhesive plaque curing. J R Soc Interface 2018; 15:20180489. [PMID: 30355807 PMCID: PMC6228490 DOI: 10.1098/rsif.2018.0489] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 09/25/2018] [Indexed: 12/12/2022] Open
Abstract
Marine mussels (Mytilus spp.) attach to a wide variety of surfaces underwater using a network of byssal threads, each tipped with a protein-based adhesive plaque that uses the surrounding seawater environment as a curing agent. Plaques undergo environmental post-processing, requiring a basic seawater pH be maintained for up to 8 days for the adhesive to strengthen completely. Given the sensitivity of plaques to local pH conditions long after deposition, we investigated the effect of other aspects of the seawater environment that are known to vary in nearshore habitats on plaque curing. The effect of seawater temperature, salinity and dissolved oxygen concentration were investigated using tensile testing, atomic force microscopy and amino acid compositional analysis. High temperature (30°C) and hyposalinity (1 PSU) had no effect on adhesion strength, while incubation in hypoxia (0.9 mg l-1) caused plaques to have a mottled coloration and prematurely peel from substrates, leading to a 51% decrease in adhesion strength. AFM imaging of the plaque cuticle found that plaques cured in hypoxia had regions of lower stiffness throughout, indicative of reductions in DOPA cross-linking between adhesive proteins. A better understanding of the dynamics of plaque curing could aid in the design of better synthetic adhesives, particularly in medicine where adhesion must take place within wet body cavities.
Collapse
Affiliation(s)
- Matthew N George
- Friday Harbor Laboratories, 620 University Road, Friday Harbor, WA 98250, USA
- Department of Biology, University of Washington, 24 Kincaid Hall, Seattle, WA 98195, USA
| | - Benjamin Pedigo
- Department of Bioengineering, University of Washington, 720 15th Avenue NE, Seattle, WA 98105, USA
| | - Emily Carrington
- Friday Harbor Laboratories, 620 University Road, Friday Harbor, WA 98250, USA
- Department of Biology, University of Washington, 24 Kincaid Hall, Seattle, WA 98195, USA
| |
Collapse
|
10
|
Dickey G, Preziosi BM, Clark CT, Bowden TJ. The impact of ocean acidification on the byssal threads of the blue mussel (Mytilus edulis). PLoS One 2018; 13:e0205908. [PMID: 30335823 PMCID: PMC6193707 DOI: 10.1371/journal.pone.0205908] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 10/03/2018] [Indexed: 11/19/2022] Open
Abstract
Blue mussel (Mytilus edulis) produce byssal threads to anchor themselves to the substrate. These threads are always exposed to the surrounding environmental conditions. Understanding how environmental pH affects these threads is crucial in understanding how climate change can affect mussels. This work examines three factors (load at failure, thread extensibility, and total thread counts) that indicate the performance of byssal threads as well as condition index to assess impacts on the physiological condition of mussels held in artificial seawater acidified by the addition of CO2. There was no significant variation between the control (~786 μatm CO2 / ~7.98 pH/ ~2805 μmol kg-1 total alkalinity) and acidified (~2555 μatm CO2 / ~7.47 pH/ ~2650 μmol kg-1 total alkalinity) treatment groups in any of these factors. The results of this study suggest that ocean acidification by CO2 addition has no significant effect on the quality and performance of threads produced by M. edulis.
Collapse
Affiliation(s)
- Grant Dickey
- School of Food and Agriculture, Aquaculture Research Institute, University of Maine, Hitchner Hall, Orono, ME, United States of America
| | - Brian M. Preziosi
- School of Food and Agriculture, Aquaculture Research Institute, University of Maine, Hitchner Hall, Orono, ME, United States of America
- * E-mail:
| | - Charles T. Clark
- School of Food and Agriculture, Aquaculture Research Institute, University of Maine, Hitchner Hall, Orono, ME, United States of America
| | - Timothy J. Bowden
- School of Food and Agriculture, Aquaculture Research Institute, University of Maine, Hitchner Hall, Orono, ME, United States of America
| |
Collapse
|
11
|
Pasche D, Horbelt N, Marin F, Motreuil S, Macías-Sánchez E, Falini G, Hwang DS, Fratzl P, Harrington MJ. A new twist on sea silk: the peculiar protein ultrastructure of fan shell and pearl oyster byssus. SOFT MATTER 2018; 14:5654-5664. [PMID: 29946583 DOI: 10.1039/c8sm00821c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Numerous mussel species produce byssal threads - tough proteinaceous fibers, which anchor mussels in aquatic habitats. Byssal threads from Mytilus species, which are comprised of modified collagen proteins - have become a veritable archetype for bio-inspired polymers due to their self-healing properties. However, threads from different species are comparatively much less understood. In particular, the byssus of Pinna nobilis comprises thousands of fine fibers utilized by humans for millennia to fashion lightweight golden fabrics known as sea silk. P. nobilis is very different from Mytilus from an ecological, morphological and evolutionary point of view and it stands to reason that the structure-function relationships of its byssus are distinct. Here, we performed compositional analysis, X-ray diffraction (XRD) and transmission electron microscopy (TEM) to investigate byssal threads of P. nobilis, as well as a closely related bivalve species (Atrina pectinata) and a distantly related one (Pinctada fucata). This comparative investigation revealed that all three threads share a similar molecular superstructure comprised of globular proteins organized helically into nanofibrils, which is completely distinct from the Mytilus thread ultrastructure, and more akin to the supramolecular organization of bacterial pili and F-actin. This unexpected discovery hints at a possible divergence in byssus evolution in Pinnidae mussels, perhaps related to selective pressures in their respective ecological niches.
Collapse
Affiliation(s)
- Delphine Pasche
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam 14424, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
|
13
|
Abstract
Materials can be made strong, but as such they are often brittle and prone to fracture when under stress. Inspired by the exceptionally strong and ductile structure of byssal threads found in certain mussels, we have designed and manufactured a multi-hierarchical steel, based on an inexpensive austenitic stainless steel, which defeats this “conflict” by possessing both superior strength and ductility. These excellent mechanical properties are realized by structurally introducing sandwich structures at both the macro- and nano-scales, the latter via an isometric, alternating, dual-phase crystal phases comprising nano-band austenite and nano-lamellar martensite, without change in chemical composition. Our experiments (transmission and scanning electron microscopy, electron back-scattered diffraction, nano-indentation and tensile tests) and micromechanics simulation results reveal a synergy of mechanisms underlying such exceptional properties. This synergy is key to the development of vastly superior mechanical properties, and may provide a unique strategy for the future development of new super strong and tough (damage-tolerant), lightweight and inexpensive structural materials.
Collapse
|
14
|
Diana A, Reguzzoni M, Congiu T, Rescigno A, Sollai F, Raspanti M. The byssus threads of Pinna nobilis: A histochemical and ultrastructural study. Eur J Histochem 2017; 61:2779. [PMID: 29313595 PMCID: PMC5695422 DOI: 10.4081/ejh.2017.2779] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 10/17/2017] [Accepted: 10/19/2017] [Indexed: 01/23/2023] Open
Abstract
The byssus of Pinna nobilis, the largest bivalve mollusc in the Mediterranean Sea, was investigated by histochemistry, immunohistochemistry, Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). At low magnification, the byssus threads appeared distinctively elliptical in cross-section, with a typical size approaching 50 x 25 micron and a featureless glassy appearance. Histochemical and immunohistochemical techniques confirmed the presence of elastic domains but the absence of collagen, which is known to be the main component in other molluscs. Ultrastructural analysis by TEM revealed the presence of at least two components within the thread, and an inner arrangement of straight, tightly packed longitudinal streaks. SEM observations while confirming the inner packing of straight, parallel subfibrils, suggested in the fracture surfaces the presence of unidentified substance which cemented together the same subfibrils and which was removed by exposure to extreme pH values. AFM micrographs added further evidence for the tight packing of subfibrils and provided some evidence of orthogonal, barely visible connecting structures. Finally, HCl or NaOH treatment left the subfibrils clean and free from any other component.Â.
Collapse
Affiliation(s)
- Andrea Diana
- University of Cagliari, Department of Biomedical Sciences.
| | | | | | | | | | | |
Collapse
|