1
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Hoyal Cuthill JF, Guttenberg N, Huertas B. Male and female contributions to diversity among birdwing butterfly images. Commun Biol 2024; 7:774. [PMID: 38951581 PMCID: PMC11217504 DOI: 10.1038/s42003-024-06376-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 05/23/2024] [Indexed: 07/03/2024] Open
Abstract
Machine learning (ML) newly enables tests for higher inter-species diversity in visible phenotype (disparity) among males versus females, predictions made from Darwinian sexual selection versus Wallacean natural selection, respectively. Here, we use ML to quantify variation across a sample of > 16,000 dorsal and ventral photographs of the sexually dimorphic birdwing butterflies (Lepidoptera: Papilionidae). Validation of image embedding distances, learnt by a triplet-trained, deep convolutional neural network, shows ML can be used for automated reconstruction of phenotypic evolution achieving measures of phylogenetic congruence to genetic species trees within a range sampled among genetic trees themselves. Quantification of sexual disparity difference (male versus female embedding distance), shows sexually and phylogenetically variable inter-species disparity. Ornithoptera exemplify high embedded male image disparity, diversification of selective optima in fitted multi-peak OU models and accelerated divergence, with cases of extreme divergence in allopatry and sympatry. However, genus Troides shows inverted patterns, including comparatively static male embedded phenotype, and higher female than male disparity - though within an inferred selective regime common to these females. Birdwing shapes and colour patterns that are most phenotypically distinctive in ML similarity are generally those of males. However, either sex can contribute majoritively to observed phenotypic diversity among species.
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Affiliation(s)
| | | | - Blanca Huertas
- Department of Science, Natural History Museum, London, UK
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2
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Jia S, Yang B, Du J, Xie Y, Yu L, Zhang Y, Tao T, Tang W, Gong J. Uncovering the Recent Progress of CNC-Derived Chirality Nanomaterials: Structure and Functions. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2401664. [PMID: 38651220 DOI: 10.1002/smll.202401664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Revised: 04/10/2024] [Indexed: 04/25/2024]
Abstract
Cellulose nanocrystal (CNC), as a renewable resource, with excellent mechanical performance, low thermal expansion coefficient, and unique optical performance, is becoming a novel candidate for the development of smart material. Herein, the recent progress of CNC-based chirality nanomaterials is uncovered, mainly covering structure regulations and function design. Undergoing a simple evaporation process, the cellulose nanorods can spontaneously assemble into chiral nematic films, accompanied by a vivid structural color. Various film structure-controlling strategies, including assembly means, physical modulation, additive engineering, surface modification, geometric structure regulation, and external field optimization, are summarized in this work. The intrinsic correlation between structure and performance is emphasized. Next, the applications of CNC-based nanomaterials is systematically reviewed. Layer-by-layer stacking structure and unique optical activity endow the nanomaterials with wide applications in the mineralization, bone regeneration, and synthesis of mesoporous materials. Besides, the vivid structural color broadens the functions in anti-counterfeiting engineering, synthesis of the shape-memory and self-healing materials. Finally, the challenges for the CNC-based nanomaterials are proposed.
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Affiliation(s)
- Shengzhe Jia
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Bingbing Yang
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Jing Du
- Department of Chemistry, Institute of Molecular Aggregation Science, Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Tianjin University, Tianjin, 300072, China
| | - Yujiang Xie
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Liuyang Yu
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Yuan Zhang
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Tiantian Tao
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Weiwei Tang
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemistry Science and Engineering, Tianjin, 300072, China
| | - Junbo Gong
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemistry Science and Engineering, Tianjin, 300072, China
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3
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Fleitas AG, Sardar S, Arnould-Pétré MM, Murace M, Vignolini S, Brodie J, Lanzani G, D'Andrea C. Influence of structural colour on the photoprotective mechanism in the gametophyte phase of the red alga Chondrus crispus. J R Soc Interface 2024; 21:20230676. [PMID: 38378137 PMCID: PMC10878799 DOI: 10.1098/rsif.2023.0676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 01/26/2024] [Indexed: 02/22/2024] Open
Abstract
Marine life is populated by a huge diversity of organisms with an incredible range of colour. While structural colour mechanisms and functions are usually well studied in marine animal species, there is a huge knowledge gap regarding the marine macroalgae (red, green and brown seaweeds) that have structural coloration and the biological significance of this phenomenon in these photosynthetic organisms. Here we show that structural colour in the gametophyte life history phase of the red alga Chondrus crispus plays an important role as a photoprotective mechanism in synergy with the other pigments present. In particular, we have demonstrated that blue structural coloration attenuates the more energetic light while simultaneously favouring green and red light harvesting through the external antennae (phycobilisomes) which possess an intensity-dependent photoprotection mechanism. These insights into the relationship between structural colour and photosynthetic light management further our understanding of the mechanisms involved.
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Affiliation(s)
- Ariel García Fleitas
- Center for Nano Science and Technology, Istituto Italiano di Tecnologia, Via Rubattino 81, 20134 Milano, Italy
- Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy
| | - Samim Sardar
- Center for Nano Science and Technology, Istituto Italiano di Tecnologia, Via Rubattino 81, 20134 Milano, Italy
| | | | - Maria Murace
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Silvia Vignolini
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Juliet Brodie
- Natural History Museum, Science, Cromwell Road, London SW7 5BD, UK
| | - Guglielmo Lanzani
- Center for Nano Science and Technology, Istituto Italiano di Tecnologia, Via Rubattino 81, 20134 Milano, Italy
- Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy
| | - Cosimo D'Andrea
- Center for Nano Science and Technology, Istituto Italiano di Tecnologia, Via Rubattino 81, 20134 Milano, Italy
- Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy
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4
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Bachem K, Li X, Ceolin S, Mühling B, Hörl D, Harz H, Leonhardt H, Arnoult L, Weber S, Matarlo B, Prud’homme B, Gompel N. Regulatory evolution tuning pigmentation intensity quantitatively in Drosophila. SCIENCE ADVANCES 2024; 10:eadl2616. [PMID: 38266088 PMCID: PMC10807792 DOI: 10.1126/sciadv.adl2616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Accepted: 12/21/2023] [Indexed: 01/26/2024]
Abstract
Quantitative variation in attributes such as color, texture, or stiffness dominates morphological diversification. It results from combinations of alleles at many Mendelian loci. Here, we identify an additional source of quantitative variation among species, continuous evolution in a gene regulatory region. Specifically, we examined the modulation of wing pigmentation in a group of fly species and showed that inter-species variation correlated with the quantitative expression of the pigmentation gene yellow. This variation results from an enhancer of yellow determining darkness through species-specific activity. We mapped the divergent activities between two sister species and found the changes to be broadly distributed along the enhancer. Our results demonstrate that enhancers can act as dials fueling quantitative morphological diversification by modulating trait properties.
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Affiliation(s)
- Katharina Bachem
- Department of Evolutionary Ecology, Ludwig-Maximilians Universität München, München 82152, Germany
| | - Xinyi Li
- Department of Evolutionary Ecology, Ludwig-Maximilians Universität München, München 82152, Germany
| | - Stefano Ceolin
- Department of Evolutionary Ecology, Ludwig-Maximilians Universität München, München 82152, Germany
| | - Bettina Mühling
- Department of Evolutionary Ecology, Ludwig-Maximilians Universität München, München 82152, Germany
| | - David Hörl
- Human Biology and Bioimaging, Ludwig-Maximilians Universität München, München 82152, Germany
| | - Hartmann Harz
- Human Biology and Bioimaging, Ludwig-Maximilians Universität München, München 82152, Germany
| | - Heinrich Leonhardt
- Human Biology and Bioimaging, Ludwig-Maximilians Universität München, München 82152, Germany
| | - Laurent Arnoult
- Institut de Biologie du Développement de Marseille, Aix-Marseille Université, Marseille 13288, France
| | - Sabrina Weber
- Department of Evolutionary Ecology, Ludwig-Maximilians Universität München, München 82152, Germany
| | - Blair Matarlo
- Department of Evolutionary Ecology, Ludwig-Maximilians Universität München, München 82152, Germany
| | - Benjamin Prud’homme
- Institut de Biologie du Développement de Marseille, Aix-Marseille Université, Marseille 13288, France
| | - Nicolas Gompel
- Department of Evolutionary Ecology, Ludwig-Maximilians Universität München, München 82152, Germany
- Bonn Institute for Organismic Biology, University of Bonn, Bonn 53115, Germany
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5
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Diepenbroek E, Pérez MB, de Beer S. PNIPAM Brushes in Colloidal Photonic Crystals Enable Ex Situ Ethanol Vapor Sensing. ACS APPLIED POLYMER MATERIALS 2024; 6:870-878. [PMID: 38230366 PMCID: PMC10788857 DOI: 10.1021/acsapm.3c02397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 11/19/2023] [Accepted: 12/04/2023] [Indexed: 01/18/2024]
Abstract
Structural colors are formed by the periodic repetition of nanostructures in a material. Upon reversibly tuning the size or optical properties of the repetitive unit inside a nanostructured material, responsive materials can be made that change color due to external stimuli. This paper presents a simple method to obtain films of ethanol vapor-responsive structural colors based on stacked poly(N-isopropylacrylamide) (PNIPAM)-grafted silica nanoparticles. Our materials show clear, reversible color transitions in the presence of near-saturated ethanol vapor. Moreover, due to the absorption of ethanol in the PNIPAM brushes, relatively long recovery times are observed (∼30 s). Materials based on bare or poly(methyl methacrylate) (PMMA) brush-grafted silica nanoparticles also change color in the presence of ethanol vapor but possess significantly shorter recovery times (∼1 s). Atomic force microscopy reveals that the delayed recovery originates from the ability of PNIPAM brushes to swell in ethanol vapor. This renders the films highly suitable for ex situ ethanol vapor sensing.
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Affiliation(s)
- Esli Diepenbroek
- Department of Molecules & Materials,
MESA+ Institute, University of Twente, 7522 NB Enschede, The Netherlands
| | - Maria Brió Pérez
- Department of Molecules & Materials,
MESA+ Institute, University of Twente, 7522 NB Enschede, The Netherlands
| | - Sissi de Beer
- Department of Molecules & Materials,
MESA+ Institute, University of Twente, 7522 NB Enschede, The Netherlands
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6
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Guidetti G, Kim T, Dutcher A, Presti ML, Ovstrovsky-Snider N, Omenetto FG. Co-modulation of structural and pigmentary coloration in Lyropteryx apollonia butterfly. OPTICS EXPRESS 2023; 31:43712-43721. [PMID: 38178461 DOI: 10.1364/oe.500130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/09/2023] [Indexed: 01/06/2024]
Abstract
Nature produces some of the most striking optical effects through the combination of structural and chemical principles to give rise to a wide range of colors. However, creating non-spectral colors that extend beyond the color spectrum is a challenging task, as it requires meeting the requirements of both structural and pigmentary coloration. In this study, we investigate the magenta non-spectral color found in the scales of the ventral spots of the Lyropteryx apollonia butterfly. By employing correlated optical and electron microscopy, as well as pigment extraction techniques, we reveal how this color arises from the co-modulation of pigmentary and structural coloration. Specifically, the angle-dependent blue coloration results from the interference of visible light with chitin-based nanostructures, while the diffused red coloration is generated by an ommochrome pigment. The ability to produce such highly conspicuous non-spectral colors provides insights for the development of hierarchical structures with precise control over their optical response. These structures can be used to create hierarchically-arranged systems with a broadened color palette.
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7
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Thayer RC, Patel NH. A meta-analysis of butterfly structural colors: their color range, distribution and biological production. J Exp Biol 2023; 226:jeb245940. [PMID: 37937662 DOI: 10.1242/jeb.245940] [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] [Indexed: 11/09/2023]
Abstract
Butterfly scales are among the richest natural sources of optical nanostructures, which produce structural color and iridescence. Several recurring nanostructure types have been described, such as ridge multilayers, gyroids and lower lamina thin films. While the optical mechanisms of these nanostructure classes are known, their phylogenetic distributions and functional ranges have not been described in detail. In this Review, we examine a century of research on the biological production of structural colors, including their evolution, development and genetic regulation. We have also created a database of more than 300 optical nanostructures in butterflies and conducted a meta-analysis of the color range, abundance and phylogenetic distribution of each nanostructure class. Butterfly structural colors are ubiquitous in short wavelengths but extremely rare in long wavelengths, especially red. In particular, blue wavelengths (around 450 nm) occur in more clades and are produced by more kinds of nanostructures than other hues. Nanostructure categories differ in prevalence, phylogenetic distribution, color range and brightness. For example, lamina thin films are the least bright; perforated lumen multilayers occur most often but are almost entirely restricted to the family Lycaenidae; and 3D photonic crystals, including gyroids, have the narrowest wavelength range (from about 450 to 550 nm). We discuss the implications of these patterns in terms of nanostructure evolution, physical constraint and relationships to pigmentary color. Finally, we highlight opportunities for future research, such as analyses of subadult and Hesperid structural colors and the identification of genes that directly build the nanostructures, with relevance for biomimetic engineering.
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Affiliation(s)
- Rachel C Thayer
- Department of Evolution and Ecology, University of California, Davis, Davis, CA 95616, USA
| | - Nipam H Patel
- Marine Biological Laboratory, Woods Hole, MA 02543, USA
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8
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Nishida K, Adachi H, Moriyama M, Futahashi R, Hanson PE, Kondo S. Butterfly wing color made of pigmented liquid. Cell Rep 2023; 42:112917. [PMID: 37537843 DOI: 10.1016/j.celrep.2023.112917] [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: 05/01/2023] [Revised: 07/05/2023] [Accepted: 07/17/2023] [Indexed: 08/05/2023] Open
Abstract
A previously undescribed mechanism underlying butterfly wing coloration patterns was discovered in two distantly related butterfly species, Siproeta stelenes and Philaethria diatonica. These butterflies have bright green wings, but the color pattern is not derived from solid pigments or nanostructures of the scales or from the color of the cuticular membrane but rather from a liquid retained in the wing membrane. Wing structure differs between the green and non-green areas. In the non-green region, the upper and lower cuticular membranes are attached to each other, whereas in the green region, we observed a space of 5-10 μm where green liquid is held and living cells are present. A pigment analysis and tracer experiment revealed that the color of the liquid is derived from hemolymph components, bilin and carotenoid pigments. This discovery broadens our understanding of the diverse ways in which butterfly wings obtain their coloration and patterns.
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Affiliation(s)
- Kenji Nishida
- Associate Researcher Museo de Zoología, Universidad de Costa Rica & Estación Biológica Monteverde, Apdo 22-5655, Monteverde, Costa Rica.
| | - Haruhiko Adachi
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Minoru Moriyama
- National Institute of Advanced Industrial Science and Technology, Central bld. 6th, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Ryo Futahashi
- National Institute of Advanced Industrial Science and Technology, Central bld. 6th, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Paul E Hanson
- Escuela de Biología & Centro de Investigación en Biodiversidad y Ecología Tropical (CIBET), Universidad de Costa Rica, San Pedro de Montes de Oca, San José, Costa Rica
| | - Shigeru Kondo
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
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9
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Jeon DJ, Ji S, Lee E, Kang J, Kim J, D'Alba L, Manceau M, Shawkey MD, Yeo JS. How keratin cortex thickness affects iridescent feather colours. ROYAL SOCIETY OPEN SCIENCE 2023; 10:220786. [PMID: 36686555 PMCID: PMC9832292 DOI: 10.1098/rsos.220786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
The bright, saturated iridescent colours of feathers are commonly produced by single and multi-layers of nanostructured melanin granules (melanosomes), air and keratin matrices, surrounded by an outer keratin cortex of varying thicknesses. The role of the keratin cortex in colour production remains unclear, despite its potential to act as a thin film or absorbing layer. We use electron microscopy, optical simulations and oxygen plasma-mediated experimental cortex removal to show that differences in keratin cortex thickness play a significant role in producing colours. The results indicate that keratin cortex thickness determines the position of the major reflectance peak (hue) from nanostructured melanosomes of common pheasant (Phasianus colchicus) feathers. Specifically, the common pheasant has appropriate keratin cortex thickness to produce blue and green structural colours. This finding identifies a general principle of structural colour production and sheds light on the processes that shaped the evolution of brilliant iridescent colours in the common pheasant.
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Affiliation(s)
- Deok-Jin Jeon
- School of Integrated Technology, Yonsei Institute of Convergence Technology, Yonsei University, Incheon 21983, Republic of Korea
| | - Seungmuk Ji
- School of Integrated Technology, Yonsei Institute of Convergence Technology, Yonsei University, Incheon 21983, Republic of Korea
| | - Eunok Lee
- Department of Research Planning, National Institute of Ecology, Chungcheongnam-do 33657, Republic of Korea
| | - Jihun Kang
- School of Integrated Technology, Yonsei Institute of Convergence Technology, Yonsei University, Incheon 21983, Republic of Korea
| | - Jiyeong Kim
- Ecological Technology Research Team, Division of Ecological Applications Research, National Institute of Ecology, Chungcheongnam-do 33657, Republic of Korea
| | - Liliana D'Alba
- Evolution and Optics of Nanostructures Group, Department of Biology, Ghent University, Ledeganckstraat 35, Ghent 9000, Belgium
- Naturalis Biodiversity Center, Darwinweg 2, Leiden 2333 CR, The Netherlands
| | - Marie Manceau
- Center for Interdisciplinary Research in Biology, CNRS UMR7241, INSERM U1050, Collège de France, Paris Sciences et Lettres University, 75006 Paris, France
| | - Matthew D. Shawkey
- Evolution and Optics of Nanostructures Group, Department of Biology, Ghent University, Ledeganckstraat 35, Ghent 9000, Belgium
| | - Jong-Souk Yeo
- School of Integrated Technology, Yonsei Institute of Convergence Technology, Yonsei University, Incheon 21983, Republic of Korea
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10
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Lee J, Jung Y, Lee M, Hwang JS, Guo J, Shin W, Min J, Pyun KR, Lee H, Lee Y, Shiomi J, Kim YJ, Kim BW, Ko SH. Biomimetic reconstruction of butterfly wing scale nanostructures for radiative cooling and structural coloration. NANOSCALE HORIZONS 2022; 7:1054-1064. [PMID: 35775456 DOI: 10.1039/d2nh00166g] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
A great number of butterfly species in the warmer climate have evolved to exhibit fascinating optical properties on their wing scales which can both regulate the wing temperature and exhibit structural coloring in order to increase their chances of survival. In particular, the Archaeoprepona demophon dorsal wing demonstrates notable radiative cooling performance and iridescent colors based on the nanostructure of the wing scale that can be characterized by the nanoporous matrix with the periodic nanograting structure on the top matrix surface. Inspired by the natural species, we demonstrate a multifunctional biomimetic film that reconstructs the nanostructure of the Archaeoprepona demophon wing scales to replicate the radiative cooling and structural coloring functionalities. We resorted to the SiO2 sacrificial template-based solution process to mimic the random porous structure and laser-interference lithography to reproduce the nanograting architecture of the butterfly wing scale. As a result, the biomimetic structure of the nanograted surface on top of the porous film demonstrated desirable heat transfer and optical properties for outstanding radiative cooling performance and iridescent structural coloring. In this regard, the film is capable of inducing the maximum temperature drop of 8.45 °C, and the color gamut of the biomimetic film can cover 91.8% of the standardized color profile (sRGB).
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Affiliation(s)
- Jinwoo Lee
- George W. Woodruff School of Mechanical Engineering, Institute for Electronics and Nanotechnology, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Yeongju Jung
- Applied Nano and Thermal Science Lab, Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea.
| | - MinJae Lee
- Applied Nano and Thermal Science Lab, Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea.
- Advanced Materials Research Team, Hyundai Motor Group, 37, Cheoldobangmulgwan-ro, Uiwang-si, Gyeonggi-do, 16082, South Korea.
| | - June Sik Hwang
- Department of Mechanical Engineering Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yusung-gu, Daejeon 34141, South Korea
| | - Jiang Guo
- Department of Mechanical Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Wooseop Shin
- Applied Nano and Thermal Science Lab, Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea.
| | - JinKi Min
- Applied Nano and Thermal Science Lab, Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea.
| | - Kyung Rok Pyun
- Applied Nano and Thermal Science Lab, Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea.
| | - Huseung Lee
- Department of Mechanical and Materials Engineering Education, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 34134, South Korea
| | - Yaerim Lee
- Department of Mechanical Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Junichiro Shiomi
- Department of Mechanical Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Young-Jin Kim
- Department of Mechanical Engineering Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yusung-gu, Daejeon 34141, South Korea
| | - Byung-Wook Kim
- Advanced Materials Research Team, Hyundai Motor Group, 37, Cheoldobangmulgwan-ro, Uiwang-si, Gyeonggi-do, 16082, South Korea.
| | - Seung Hwan Ko
- Applied Nano and Thermal Science Lab, Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea.
- Institute of Advanced Machinery and Design (SNU-IAMD), Seoul National University, Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
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11
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Autofluorescent Biomolecules in Diptera: From Structure to Metabolism and Behavior. Molecules 2022; 27:molecules27144458. [PMID: 35889334 PMCID: PMC9318335 DOI: 10.3390/molecules27144458] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/08/2022] [Accepted: 07/08/2022] [Indexed: 02/04/2023] Open
Abstract
Light-based phenomena in insects have long attracted researchers’ attention. Surface color distribution patterns are commonly used for taxonomical purposes, while optically-active structures from Coleoptera cuticle or Lepidoptera wings have inspired technological applications, such as biosensors and energy accumulation devices. In Diptera, besides optically-based phenomena, biomolecules able to fluoresce can act as markers of bio-metabolic, structural and behavioral features. Resilin or chitinous compounds, with their respective blue or green-to-red autofluorescence (AF), are commonly related to biomechanical and structural properties, helpful to clarify the mechanisms underlying substrate adhesion of ectoparasites’ leg appendages, or the antennal abilities in tuning sound detection. Metarhodopsin, a red fluorescing photoproduct of rhodopsin, allows to investigate visual mechanisms, whereas NAD(P)H and flavins, commonly relatable to energy metabolism, favor the investigation of sperm vitality. Lipofuscins are AF biomarkers of aging, as well as pteridines, which, similarly to kynurenines, are also exploited in metabolic investigations. Beside the knowledge available in Drosophila melanogaster, a widely used model to study also human disorder and disease mechanisms, here we review optically-based studies in other dipteran species, including mosquitoes and fruit flies, discussing future perspectives for targeted studies with various practical applications, including pest and vector control.
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12
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Penick CA, Cope G, Morankar S, Mistry Y, Grishin A, Chawla N, Bhate D. The Comparative approach to bio-inspired design: integrating biodiversity and biologists into the design process. Integr Comp Biol 2022; 62:icac097. [PMID: 35767863 DOI: 10.1093/icb/icac097] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Biodiversity provides a massive library of ideas for bio-inspired design, but the sheer number of species to consider can be daunting. Current approaches for sifting through biodiversity to identify relevant biological models include searching for champion adapters that are particularly adept at solving a particular design challenge. While the champion adapter approach has benefits, it tends to focus on a narrow set of popular models while neglecting the majority of species. An alternative approach to bio-inspired design is the comparative method, which leverages biodiversity by drawing inspiration across a broad range of species. This approach uses methods in phylogenetics to map traits across evolutionary trees and compare trait variation to infer structure-function relationships. Although comparative methods have not been widely used in bio-inspired design, they have led to breakthroughs in studies on gecko-inspired adhesives and multifunctionality of butterfly wing scales. Here we outline how comparative methods can be used to complement existing approaches to bioinspired design, and we provide an example focused on bio-inspired lattices, including honeycomb and glass sponges. We demonstrate how comparative methods can lead to breakthroughs in bio-inspired applications as well as answer major questions in biology, which can strengthen collaborations with biologists and produce deeper insights into biological function.
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Affiliation(s)
- Clint A Penick
- Department of Ecology, Evolution, and Organismal Biology, Kennesaw State University, Kennesaw, GA, 30144USA
| | - Grace Cope
- Department of Ecology, Evolution, and Organismal Biology, Kennesaw State University, Kennesaw, GA, 30144USA
| | - Swapnil Morankar
- School of Materials Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Yash Mistry
- 3DX Research Group, Arizona State University, Mesa, AZ 85212, USA
| | - Alex Grishin
- Phoenix Analysis & Design Technologies, Inc., Tempe, AZ 85284, USA
| | - Nikhilesh Chawla
- School of Materials Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Dhruv Bhate
- 3DX Research Group, Arizona State University, Mesa, AZ 85212, USA
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13
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At the Intersection of Natural Structural Coloration and Bioengineering. Biomimetics (Basel) 2022; 7:biomimetics7020066. [PMID: 35645193 PMCID: PMC9149877 DOI: 10.3390/biomimetics7020066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/11/2022] [Accepted: 05/12/2022] [Indexed: 02/04/2023] Open
Abstract
Most of us get inspired by and interact with the world around us based on visual cues such as the colors and patterns that we see. In nature, coloration takes three primary forms: pigmentary coloration, structural coloration, and bioluminescence. Typically, pigmentary and structural coloration are used by animals and plants for their survival; however, few organisms are able to capture the nearly instantaneous and visually astounding display that cephalopods (e.g., octopi, squid, and cuttlefish) exhibit. Notably, the structural coloration of these cephalopods critically relies on a unique family of proteins known as reflectins. As a result, there is growing interest in characterizing the structure and function of such optically-active proteins (e.g., reflectins) and to leverage these materials across a broad range of disciplines, including bioengineering. In this review, I begin by briefly introducing pigmentary and structural coloration in animals and plants as well as highlighting the extraordinary appearance-changing capabilities of cephalopods. Next, I outline recent advances in the characterization and utilization of reflectins for photonic technologies and and discuss general strategies and limitations for the structural and optical characterization of proteins. Finally, I explore future directions of study for optically-active proteins and their potential applications. Altogether, this review aims to bring together an interdisciplinary group of researchers who can resolve the fundamental questions regarding the structure, function, and self-assembly of optically-active protein-based materials.
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14
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McCoy DE, Shneidman AV, Davis AL, Aizenberg J. Finite-difference Time-domain (FDTD) Optical Simulations: A Primer for the Life Sciences and Bio-Inspired Engineering. Micron 2021; 151:103160. [PMID: 34678583 DOI: 10.1016/j.micron.2021.103160] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 09/22/2021] [Accepted: 09/27/2021] [Indexed: 10/20/2022]
Abstract
Light influences most ecosystems on earth, from sun-dappled forests to bioluminescent creatures in the ocean deep. Biologists have long studied nano- and micro-scale organismal adaptations to manipulate light using ever-more sophisticated microscopy, spectroscopy, and other analytical equipment. In combination with experimental tools, simulations of light interacting with objects can help researchers determine the impact of observed structures and explore how variations affect optical function. In particular, the finite-difference time-domain (FDTD) method is widely used throughout the nanophotonics community to efficiently simulate light interacting with a variety of materials and optical devices. More recently, FDTD has been used to characterize optical adaptations in nature, such as camouflage in fish and other organisms, colors in sexually-selected birds and spiders, and photosynthetic efficiency in plants. FDTD is also common in bioengineering, as the design of biologically-inspired engineered structures can be guided and optimized through FDTD simulations. Parameter sweeps are a particularly useful application of FDTD, which allows researchers to explore a range of variables and modifications in natural and synthetic systems (e.g., to investigate the optical effects of changing the sizes, shape, or refractive indices of a structure). Here, we review the use of FDTD simulations in biology and present a brief methods primer tailored for life scientists, with a focus on the commercially available software Lumerical FDTD. We give special attention to whether FDTD is the right tool to use, how experimental techniques are used to acquire and import the structures of interest, and how their optical properties such as refractive index and absorption are obtained. This primer is intended to help researchers understand FDTD, implement the method to model optical effects, and learn about the benefits and limitations of this tool. Altogether, FDTD is well-suited to (i) characterize optical adaptations and (ii) provide mechanistic explanations; by doing so, it helps (iii) make conclusions about evolutionary theory and (iv) inspire new technologies based on natural structures.
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Affiliation(s)
- Dakota E McCoy
- Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, USA; Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Anna V Shneidman
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, 9 Oxford Street, Cambridge, MA, 02138, USA.
| | - Alexander L Davis
- Department of Biology, Duke University, Campus Box 90338, Durham, NC, 27708, USA
| | - Joanna Aizenberg
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, 9 Oxford Street, Cambridge, MA, 02138, USA; Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA, 02138, USA
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15
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Chen S, Haehnle B, Van der Laan X, Kuehne AJC, Botiz I, Stavrinou PN, Stingelin N. Understanding hierarchical spheres-in-grating assembly for bio-inspired colouration. MATERIALS HORIZONS 2021; 8:2230-2237. [PMID: 34846427 DOI: 10.1039/d1mh00358e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The vivid iridescent response from particular butterflies is as an excellent example of how micro-engineered hierarchical architectures that combine physical structures and pigmentary inclusions create unique colouration. To date, however, detailed knowledge is missing to replicate such sophisticated structures in a robust, reliable manner. Here, we deliver spheres-in-grating assemblies with colouration effects as found in nature, exploiting embossed polymer gratings and self-assembled light-absorbing micro-spheres.
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Affiliation(s)
- Shengyang Chen
- Department of Materials and Centre of Plastic Electronics, Imperial College London, London SW7 2AZ, UK
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16
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Bermúdez-Ureña E, Kilchoer C, Lord NP, Steiner U, Wilts BD. Structural Diversity with Varying Disorder Enables the Multicolored Display in the Longhorn Beetle Sulawesiella rafaelae. iScience 2020; 23:101339. [PMID: 32688285 PMCID: PMC7371903 DOI: 10.1016/j.isci.2020.101339] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 06/24/2020] [Accepted: 06/30/2020] [Indexed: 12/16/2022] Open
Abstract
Light control through layered photonic nanostructures enables the strikingly colored displays of many beetles, birds, and butterflies. To achieve different reflected colors, natural organisms mainly rely on refractive index variations or scaling of a fixed structure design, as opposed to varying the type of structure. Here, we describe the presence of distinct coloration mechanisms in the longhorn beetle Sulawesiella rafaelae, which exhibits turquoise, yellow-green, and orange colors, each with a variable iridescence. By optical and electron microscopy, we show that the colors originate from multilayered architectures in hair-like scales with varying amounts of structural disorder. Structural characterizations and optical modeling show that the disorder strongly influences the optical properties of the scales, allowing an independent adjustment of the optical response. Our results shed light on the interplay of disorder in multilayered photonic structures and their biological significance, and could potentially inspire new ecological research and the development of novel optical components.
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Affiliation(s)
- Esteban Bermúdez-Ureña
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland.
| | - Cédric Kilchoer
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Nathan P Lord
- Department of Entomology, Louisiana State University Agricultural Center, 404 Life Sciences Building, LSU, Baton Rouge, LA 70803, USA
| | - Ullrich Steiner
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Bodo D Wilts
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland.
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17
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Nishiyama R, Yoshioka S. Detailed analysis of photonic structure in the wing scale of Rajah Brooke's birdwing butterfly. OPTICS EXPRESS 2020; 28:16782-16794. [PMID: 32549493 DOI: 10.1364/oe.396262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 05/12/2020] [Indexed: 06/11/2023]
Abstract
The male Rajah Brooke's birdwing butterfly, Trogonoptera brookiana, has black wings with bright green stripes, and the unique microstructure in the wing scales causes wavelength-selective reflection. It has been reported that the reflectance spectrum has several peaks in the visible wavelength range. However, there has been little progress in the interpretation of the spectral shape, and questions remain unanswered. For example, what are the physical origins of the observed reflectance peaks, and how are their wavelengths determined? To answer these questions, we performed a detailed analysis of the photonic structure of the wing scale of Trogonopterabrookiana. The reflectance spectrum also shows strong polarization dependence. This paper describes the analysis for TM polarization, which is perpendicular to the longitudinal ridges on the scale. We first constructed a realistic structural model that reproduced the experimentally determined reflectance spectrum. We then simplified the model and calculated the reflectance spectrum while varying several structural parameters. For three of the four observed spectral peaks, our calculations revealed the reflection paths for constructive interference to explain the peak wavelengths. A possible origin of the fourth peak is discussed. Such detailed understanding of natural photonic structures can inspire optical component design.
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18
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Stavenga DG, Wallace JRA, Warrant EJ. Bogong Moths Are Well Camouflaged by Effectively Decolourized Wing Scales. Front Physiol 2020; 11:95. [PMID: 32116798 PMCID: PMC7026391 DOI: 10.3389/fphys.2020.00095] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Accepted: 01/27/2020] [Indexed: 11/13/2022] Open
Abstract
Moth wings are densely covered by wing scales that are assumed to specifically function to camouflage nocturnally active species during day time. Generally, moth wing scales are built according to the basic lepidopteran Bauplan, where the upper lamina consists of an array of parallel ridges and the lower lamina is a thin plane. The lower lamina hence acts as a thin film reflector having distinct reflectance spectra that can make the owner colorful and thus conspicuous for predators. Most moth species therefore load the scales’ upper lamina with variable amounts of melanin so that dull, brownish color patterns result. We investigated whether scale pigmentation in this manner indeed provides moths with camouflage by comparing the reflectance spectra of the wings and scales of the Australian Bogong moth (Agrotis infusa) with those of objects in their natural environment. The similarity of the spectra underscores the effective camouflaging strategies of this moth species.
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Affiliation(s)
- Doekele G Stavenga
- Surfaces and Thin Films, Zernike Institute for Advanced Materials, University of Groningen, Groningen, Netherlands
| | - Jesse R A Wallace
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Eric J Warrant
- Research School of Biology, Australian National University, Canberra, ACT, Australia.,Lund Vision Group, Department of Biology, Lund University, Lund, Sweden
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19
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Orientation-Dependent Reflection of Structurally Coloured Butterflies. Biomimetics (Basel) 2020; 5:biomimetics5010005. [PMID: 32028633 PMCID: PMC7148507 DOI: 10.3390/biomimetics5010005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/31/2020] [Accepted: 02/01/2020] [Indexed: 11/17/2022] Open
Abstract
The photonic structures of butterfly wing scales are widely known to cause angle-dependent colours by light interference with nanostructures present in the wing scales. Here, we quantify the relevance of the horizontal alignment of the butterfly wing scales on the wing. The orientation-dependent reflection was measured at four different azimuth angles, with a step size of 90°, for ten samples—two of different areas of the same species—of eight butterfly species of three subfamilies at constant angles of illumination and observation. For the observed species with varying optical structures, the wing typically exhibits higher orientation-dependent reflections than the individual scale. We find that the measured anisotropy is caused by the commonly observed grating structures that can be found on all butterfly wing scales, rather than the local photonic structures. Our results show that the technique employed here can be used to quickly evaluate the orientation-dependence of the reflection and hence provide important input for bio-inspired applications, e.g., to identify whether the respective structure is suitable as a template for nano-imprinting techniques.
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20
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Infrared optical and thermal properties of microstructures in butterfly wings. Proc Natl Acad Sci U S A 2020; 117:1566-1572. [PMID: 31919285 DOI: 10.1073/pnas.1906356117] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
While surface microstructures of butterfly wings have been extensively studied for their structural coloration or optical properties within the visible spectrum, their properties in infrared wavelengths with potential ties to thermoregulation are relatively unknown. The midinfrared wavelengths of 7.5 to 14 µm are particularly important for radiative heat transfer in the ambient environment, because of the overlap with the atmospheric transmission window. For instance, a high midinfrared emissivity can facilitate surface cooling, whereas a low midinfrared emissivity can minimize heat loss to surroundings. Here we find that the midinfrared emissivity of butterfly wings from warmer climates such as Archaeoprepona demophoon (Oaxaca, Mexico) and Heliconius sara (Pichincha, Ecuador) is up to 2 times higher than that of butterfly wings from cooler climates such as Celastrina echo (Colorado) and Limenitis arthemis (Florida), using Fourier-transform infrared (FTIR) spectroscopy and infrared thermography. Our optical computations using a unit cell approach reproduce the spectroscopy data and explain how periodic microstructures play a critical role in the midinfrared. The emissivity spectrum governs the temperature of butterfly wings, and we demonstrate that C. echo wings heat up to 8 °C more than A. demophoon wings under the same sunlight in the clear sky of Irvine, CA. Furthermore, our thermal computations show that butterfly wings in their respective habitats can maintain a moderate temperature range through a balance of solar absorption and infrared emission. These findings suggest that the surface microstructures of butterfly wings potentially contribute to thermoregulation and provide an insight into butterflies' survival.
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21
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Wilts BD, Mothander K, Kelber A. Humidity-dependent colour change in the green forester moth, Adscita statices. Biol Lett 2019; 15:20190516. [PMID: 31530115 PMCID: PMC6769142 DOI: 10.1098/rsbl.2019.0516] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 08/22/2019] [Indexed: 11/12/2022] Open
Abstract
The colours of insects serve important visual functions in aiding mate recognition, camouflage and warning. The display of insects is usually static, as cuticle coloration does not (or hardly) change during the lifespan of a mature imago form. Here, we describe a case of humidity-dependent, brilliant coloration in the green forester moth, Adscita statices. We show, by employing spectroscopic and ultrastructural methods, that the moth's colour results from the interference of incident light with an unusual hydrophilic melanized-chitin multilayer present in the wing scales. Humidity changes in the environment affect the multilayer properties, causing a significant shift of the green-peaking reflectance in the dry state to a rusty colour when damp, resulting in the strong colour change between day and dusk or dawn.
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Affiliation(s)
- Bodo D. Wilts
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Karolina Mothander
- Vision Group, Department of Biology, Lund University, Sölvegatan 35, 22362 Lund, Sweden
| | - Almut Kelber
- Vision Group, Department of Biology, Lund University, Sölvegatan 35, 22362 Lund, Sweden
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22
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Day CR, Hanly JJ, Ren A, Martin A. Sub-micrometer insights into the cytoskeletal dynamics and ultrastructural diversity of butterfly wing scales. Dev Dyn 2019; 248:657-670. [PMID: 31107575 DOI: 10.1002/dvdy.63] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/13/2019] [Accepted: 05/16/2019] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND The color patterns that adorn lepidopteran wings are ideal for studying cell type diversity using a phenomics approach. Color patterns are made of chitinous scales that are each the product of a single precursor cell, offering a 2D system where phenotypic diversity can be studied cell by cell, both within and between species. Those scales reveal complex ultrastructures in the sub-micrometer range that are often connected to a photonic function, including iridescent blues and greens, highly reflective whites, or light-trapping blacks. RESULTS We found that during scale development, Fascin immunostainings reveal punctate distributions consistent with a role in the control of actin patterning. We quantified the cytoskeleton regularity as well as its relationship to chitin deposition sites, and confirmed a role in the patterning of the ultrastructures of the adults scales. Then, in an attempt to characterize the range and variation in lepidopteran scale ultrastructures, we devised a high-throughput method to quickly derive multiple morphological measurements from fluorescence images and scanning electron micrographs. We imaged a multicolor eyespot element from the butterfly Vanessa cardui (V. cardui), taking approximately 200 000 individual measurements from 1161 scales. Principal component analyses revealed that scale structural features cluster by color type, and detected the divergence of non-reflective scales characterized by tighter cross-rib distances and increased orderedness. CONCLUSION We developed descriptive methods that advance the potential of butterfly wing scales as a model system for studying how a single cell type can differentiate into a multifaceted spectrum of complex morphologies. Our data suggest that specific color scales undergo a tight regulation of their ultrastructures, and that this involves cytoskeletal dynamics during scale growth.
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Affiliation(s)
- Christopher R Day
- Department of Biological Sciences, The George Washington University, Washington, District of Columbia.,Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, North Carolina
| | - Joseph J Hanly
- Department of Biological Sciences, The George Washington University, Washington, District of Columbia
| | - Anna Ren
- Department of Biological Sciences, The George Washington University, Washington, District of Columbia
| | - Arnaud Martin
- Department of Biological Sciences, The George Washington University, Washington, District of Columbia
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23
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Iwata M, Otaki JM. Insights into eyespot color-pattern formation mechanisms from color gradients, boundary scales, and rudimentary eyespots in butterfly wings. JOURNAL OF INSECT PHYSIOLOGY 2019; 114:68-82. [PMID: 30797779 DOI: 10.1016/j.jinsphys.2019.02.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 02/20/2019] [Accepted: 02/20/2019] [Indexed: 06/09/2023]
Abstract
Butterfly eyespot color patterns are traditionally explained by the gradient model, where positional information is stably provided by a morphogen gradient from a single organizer and its output is a set of non-graded (or graded) colors based on pre-determined threshold levels. An alternative model is the induction model, in which the outer black ring and the inner black core disk of an eyespot are specified by graded signals from the primary and secondary organizers that also involve lateral induction. To examine the feasibility of these models, we analyzed eyespot color gradients, boundary scales, and rudimentary eyespots in various nymphalid butterflies. Most parts of eyespots showed color gradients with gradual or fluctuating changes with sharp boundaries in many species, but some species had eyespots that were composed of a constant color within a given part. Thus, a plausible model should be flexible enough to incorporate this diversity. Some boundary scales appeared to have two kinds of pigments, and others had "misplaced" colors, suggesting an overlapping of two signals and a difficulty in assuming sharp threshold boundaries. Rudimentary eyespots of three Junonia species revealed that the outer black ring is likely determined first and the inner yellow or red ring is laterally induced. This outside-to-inside determination together with the lateral induction may favor the induction model, in which dynamic signal interactions play a major role. The implications of these results for the ploidy hypothesis and color-pattern rules are discussed.
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Affiliation(s)
- Masaki Iwata
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Senbaru, Nishihara, Okinawa 903-0213, Japan; Department of International Agricultural Development, Faculty of International Agriculture and Food Studies, Tokyo University of Agriculture, Sakuragaoka, Setagaya, Tokyo 156-8502, Japan
| | - Joji M Otaki
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Senbaru, Nishihara, Okinawa 903-0213, Japan.
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24
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Kilchoer C, Steiner U, Wilts BD. Thin-film structural coloration from simple fused scales in moths. Interface Focus 2018; 9:20180044. [PMID: 30603066 DOI: 10.1098/rsfs.2018.0044] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/08/2018] [Indexed: 11/12/2022] Open
Abstract
The metallic coloration of insects often originates from diverse nanostructures ranging from simple thin films to complex three-dimensional photonic crystals. In Lepidoptera, structural coloration is widely present and seems to be abundant in extant species. However, even some basal moths exhibit metallic coloration. Here, we have investigated the origin of the vivid metallic colours of the wing scales of the basal moth Micropterix aureatella by spectrophotometry and scanning electron microscopy. The metallic gold-, bronze- and purple-coloured scales share a similar anatomy formed of a fused lower and upper lamina resulting in a single thin film. The optical response of this thin-film scale can be attributed to thin-film interference of the incident light, resulting in the colour variations that correlate with film thickness. Subtle variations in the wing scale thickness result in large visible colour changes that give Micropterix moths their colourful wing patterns. This simple coloration mechanism could provide a hint to understand the evolution of structural coloration in Lepidoptera.
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Affiliation(s)
- Cédric Kilchoer
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Ullrich Steiner
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Bodo D Wilts
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
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25
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Schroeder TBH, Houghtaling J, Wilts BD, Mayer M. It's Not a Bug, It's a Feature: Functional Materials in Insects. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1705322. [PMID: 29517829 DOI: 10.1002/adma.201705322] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 11/15/2017] [Indexed: 05/25/2023]
Abstract
Over the course of their wildly successful proliferation across the earth, the insects as a taxon have evolved enviable adaptations to their diverse habitats, which include adhesives, locomotor systems, hydrophobic surfaces, and sensors and actuators that transduce mechanical, acoustic, optical, thermal, and chemical signals. Insect-inspired designs currently appear in a range of contexts, including antireflective coatings, optical displays, and computing algorithms. However, as over one million distinct and highly specialized species of insects have colonized nearly all habitable regions on the planet, they still provide a largely untapped pool of unique problem-solving strategies. With the intent of providing materials scientists and engineers with a muse for the next generation of bioinspired materials, here, a selection of some of the most spectacular adaptations that insects have evolved is assembled and organized by function. The insects presented display dazzling optical properties as a result of natural photonic crystals, precise hierarchical patterns that span length scales from nanometers to millimeters, and formidable defense mechanisms that deploy an arsenal of chemical weaponry. Successful mimicry of these adaptations may facilitate technological solutions to as wide a range of problems as they solve in the insects that originated them.
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Affiliation(s)
- Thomas B H Schroeder
- Department of Chemical Engineering, University of Michigan, 2300 Hayward Street, Ann Arbor, MI, 48109, USA
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700, Fribourg, Switzerland
| | - Jared Houghtaling
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700, Fribourg, Switzerland
- Department of Biomedical Engineering, University of Michigan, 2200 Bonisteel Boulevard, Ann Arbor, MI, 48109, USA
| | - Bodo D Wilts
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700, Fribourg, Switzerland
| | - Michael Mayer
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700, Fribourg, Switzerland
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26
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Stavenga DG, Leertouwer HL, Meglič A, Drašlar K, Wehling MF, Pirih P, Belušič G. Classical lepidopteran wing scale colouration in the giant butterfly-moth Paysandisia archon. PeerJ 2018; 6:e4590. [PMID: 29666756 PMCID: PMC5899422 DOI: 10.7717/peerj.4590] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 03/19/2018] [Indexed: 11/30/2022] Open
Abstract
The palm borer moth Paysandisia archon (Castniidae; giant butterfly-moths) has brown dorsal forewings and strikingly orange-coloured dorsal hindwings with white spots surrounded by black margins. Here, we have studied the structure and pigments of the wing scales in the various coloured wing areas, applying light and electron microscopy and (micro)spectrophotometry, and we analysed the spatial reflection properties with imaging scatterometry. The scales in the white spots are unpigmented, those in the black and brown wing areas contain various amounts of melanin, and the orange wing scales contain a blue-absorbing ommochrome pigment. In all scale types, the upper lamina acts as a diffuser and the lower lamina as a thin film interference reflector, with thickness of about 200 nm. Scale stacking plays an important role in creating the strong visual signals: the colour of the white eyespots is created by stacks of unpigmented blue scales, while the orange wing colour is strongly intensified by stacking the orange scales.
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Affiliation(s)
- Doekele G Stavenga
- Department of Computational Physics, University of Groningen, Groningen, Netherlands
| | - Hein L Leertouwer
- Department of Computational Physics, University of Groningen, Groningen, Netherlands
| | - Andrej Meglič
- Department of Biology, University of Ljubljana, Ljubljana, Slovenia
| | - Kazimir Drašlar
- Department of Biology, University of Ljubljana, Ljubljana, Slovenia
| | | | - Primož Pirih
- Department of Computational Physics, University of Groningen, Groningen, Netherlands
| | - Gregor Belušič
- Department of Biology, University of Ljubljana, Ljubljana, Slovenia
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27
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Fifty shades of white: how white feather brightness differs among species. Naturwissenschaften 2018; 105:18. [DOI: 10.1007/s00114-018-1543-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 01/30/2018] [Accepted: 02/02/2018] [Indexed: 12/30/2022]
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Wilts BD, Vey AJM, Briscoe AD, Stavenga DG. Longwing (Heliconius) butterflies combine a restricted set of pigmentary and structural coloration mechanisms. BMC Evol Biol 2017; 17:226. [PMID: 29162029 PMCID: PMC5699198 DOI: 10.1186/s12862-017-1073-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 11/15/2017] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Longwing butterflies, Heliconius sp., also called heliconians, are striking examples of diversity and mimicry in butterflies. Heliconians feature strongly colored patterns on their wings, arising from wing scales colored by pigments and/or nanostructures, which serve as an aposematic signal. RESULTS Here, we investigate the coloration mechanisms among several species of Heliconius by applying scanning electron microscopy, (micro)spectrophotometry, and imaging scatterometry. We identify seven kinds of colored scales within Heliconius whose coloration is derived from pigments, nanostructures or both. In yellow-, orange- and red-colored wing patches, both cover and ground scales contain wavelength-selective absorbing pigments, 3-OH-kynurenine, xanthommatin and/or dihydroxanthommatin. In blue wing patches, the cover scales are blue either due to interference of light in the thin-film lower lamina (e.g., H. doris) or in the multilayered lamellae in the scale ridges (so-called ridge reflectors, e.g., H. sara and H. erato); the underlying ground scales are black. In the white wing patches, both cover and ground scales are blue due to their thin-film lower lamina, but because they are stacked upon each other and at the wing substrate, a faint bluish to white color results. Lastly, green wing patches (H. doris) have cover scales with blue-reflecting thin films and short-wavelength absorbing 3-OH-kynurenine, together causing a green color. CONCLUSIONS The pigmentary and structural traits are discussed in relation to their phylogenetic distribution and the evolution of vision in this highly interesting clade of butterflies.
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Affiliation(s)
- Bodo D Wilts
- Computational Physics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, NL-9747AG, Groningen, The Netherlands.
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700, Fribourg, Switzerland.
| | - Aidan J M Vey
- Computational Physics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, NL-9747AG, Groningen, The Netherlands
| | - Adriana D Briscoe
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, 92697, USA
| | - Doekele G Stavenga
- Computational Physics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, NL-9747AG, Groningen, The Netherlands
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van der Kooi CJ, Elzenga JTM, Dijksterhuis J, Stavenga DG. Functional optics of glossy buttercup flowers. J R Soc Interface 2017; 14:rsif.2016.0933. [PMID: 28228540 DOI: 10.1098/rsif.2016.0933] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 01/27/2017] [Indexed: 11/12/2022] Open
Abstract
Buttercup (Ranunculus spp.) flowers are exceptional because they feature a distinct gloss (mirror-like reflection) in addition to their matte-yellow coloration. We investigated the optical properties of yellow petals of several Ranunculus and related species using (micro)spectrophotometry and anatomical methods. The contribution of different petal structures to the overall visual signal was quantified using a recently developed optical model. We show that the coloration of glossy buttercup flowers is due to a rare combination of structural and pigmentary coloration. A very flat, pigment-filled upper epidermis acts as a thin-film reflector yielding the gloss, and additionally serves as a filter for light backscattered by the strongly scattering starch and mesophyll layers, which yields the matte-yellow colour. We discuss the evolution of the gloss and its two likely functions: it provides a strong visual signal to insect pollinators and increases the reflection of sunlight to the centre of the flower in order to heat the reproductive organs.
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Affiliation(s)
- Casper J van der Kooi
- Computational Physics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands .,Department of Ecology and Evolution, University of Lausanne, Le Biophore, 1015 Lausanne, Switzerland
| | - J Theo M Elzenga
- Plant Ecophysiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Jan Dijksterhuis
- CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3508 AD Utrecht, The Netherlands
| | - Doekele G Stavenga
- Computational Physics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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Changes in structural and pigmentary colours in response to cold stress in Polyommatus icarus butterflies. Sci Rep 2017; 7:1118. [PMID: 28442788 PMCID: PMC5430924 DOI: 10.1038/s41598-017-01273-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 03/28/2017] [Indexed: 11/15/2022] Open
Abstract
While numerous papers have investigated the effects of thermal stress on the pigmentary colours of butterfly wings, such studies regarding structural colours are mostly lacking, despite the important role they play in sexual communication. To gain insight into the possible differences between the responses of the two kinds of colouration, we investigated the effects of prolonged cold stress (cooling at 5 °C for up to 62 days) on the pupae of Polyommatus icarus butterflies. The wing surfaces coloured by photonic crystal-type nanoarchitectures (dorsal) and by pigments (ventral) showed markedly different behaviours. The ventral wing surfaces exhibited stress responses proportional in magnitude to the duration of cooling and showed the same trend for all individuals, irrespective of their sex. On the dorsal wing surface of the males, with blue structural colouration, a smaller magnitude response was found with much more pronounced individual variations, possibly revealing hidden genetic variations. Despite the typical, pigmented brown colour of the dorsal wing surface of the females, all cooled females exhibited a certain degree of blue colouration. UV-VIS spectroscopy, optical microscopy, and scanning and transmission electron microscopy were used to evaluate the magnitude and character of the changes induced by the prolonged cold stress.
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Siddique RH, Vignolini S, Bartels C, Wacker I, Hölscher H. Colour formation on the wings of the butterfly Hypolimnas salmacis by scale stacking. Sci Rep 2016; 6:36204. [PMID: 27805005 PMCID: PMC5090330 DOI: 10.1038/srep36204] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 10/12/2016] [Indexed: 11/16/2022] Open
Abstract
The butterfly genus Hypolimnas features iridescent blue colouration in some areas of its dorsal wings. Here, we analyse the mechanisms responsible for such colouration on the dorsal wings of Hypolimnas salmacis and experimentally demonstrate that the lower thin lamina in the white cover scales causes the blue iridescence. This outcome contradicts other studies reporting that the radiant blue in Hypolimnas butterflies is caused by complex ridge-lamellar architectures in the upper lamina of the cover scales. Our comprehensive optical study supported by numerical calculation however shows that scale stacking primarily induces the observed colour appearance of Hypolimnas salmacis.
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Affiliation(s)
- Radwanul Hasan Siddique
- Institute of Microstructure Technology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.,Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Silvia Vignolini
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Carolin Bartels
- Centre for Advanced Materials (CAM), University of Heidelberg, 69120 Heidelberg, Germany
| | - Irene Wacker
- Centre for Advanced Materials (CAM), University of Heidelberg, 69120 Heidelberg, Germany
| | - Hendrik Hölscher
- Institute of Microstructure Technology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
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Wilts BD, Giraldo MA, Stavenga DG. Unique wing scale photonics of male Rajah Brooke's birdwing butterflies. Front Zool 2016; 13:36. [PMID: 27525030 PMCID: PMC4983073 DOI: 10.1186/s12983-016-0168-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 08/04/2016] [Indexed: 11/10/2022] Open
Abstract
Background Ultrastructures in butterfly wing scales can take many shapes, resulting in the often striking coloration of many butterflies due to interference of light. The plethora of coloration mechanisms is dazzling, but often only single mechanisms are described for specific animals. Results We have here investigated the male Rajah Brooke’s birdwing, Trogonoptera brookiana, a large butterfly from Malaysia, which is marked by striking, colorful wing patterns. The dorsal side is decorated with large, iridescent green patterning, while the ventral side of the wings is primarily brown-black with small white, blue and green patches on the hindwings. Dense arrays of red hairs, creating a distinct collar as well as contrasting areas ventrally around the thorax, enhance the butterfly’s beauty. The remarkable coloration is realized by a diverse number of intricate and complicated nanostructures in the hairs as well as the wing scales. The red collar hairs contain a broad-band absorbing pigment as well as UV-reflecting multilayers resembling the photonic structures of Morpho butterflies; the white wing patches consist of scales with prominent thin film reflectors; the blue patches have scales with ridge multilayers and these scales also have centrally concentrated melanin. The green wing areas consist of strongly curved scales, which possess a uniquely arranged photonic structure consisting of multilayers and melanin baffles that produces highly directional reflections. Conclusion Rajah Brooke’s birdwing employs a variety of structural and pigmentary coloration mechanisms to achieve its stunning optical appearance. The intriguing usage of order and disorder in related photonic structures in the butterfly wing scales may inspire novel optical materials as well as investigations into the development of these nanostructures in vivo.
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Affiliation(s)
- Bodo D Wilts
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg, Switzerland
| | - Marco A Giraldo
- Biophysics Group, Institute of Physics, University of Antioquia, Calle 70 No. 52-21, A.A.1226, Medellín, Colombia
| | - Doekele G Stavenga
- Computational Physics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, NL-9747AG Groningen, The Netherlands
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Igic B, D'Alba L, Shawkey MD. Manakins can produce iridescent and bright feather colours without melanosomes. J Exp Biol 2016; 219:1851-9. [DOI: 10.1242/jeb.137182] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 03/23/2016] [Indexed: 11/20/2022]
Abstract
ABSTRACT
Males of many species often use colourful and conspicuous ornaments to attract females. Among these, male manakins (family: Pipridae) provide classic examples of sexual selection favouring the evolution of bright and colourful plumage coloration. The highly iridescent feather colours of birds are most commonly produced by the periodic arrangement of melanin-containing organelles (melanosomes) within barbules. Melanin increases the saturation of iridescent colours seen from optimal viewing angles by absorbing back-scattered light; however, this may reduce the wide-angle brightness of these signals, contributing to a dark background appearance. We examined the nanostructure of four manakin species (Lepidothrix isidorei, L. iris, L. nattereri and L. coeruleocapilla) to identify how they produce their bright plumage colours. Feather barbs of all four species were characterized by dense and fibrous internal spongy matrices that likely increase scattering of light within the barb. The iridescent, yet pale or whitish colours of L. iris and L. nattereri feathers were produced not by periodically arranged melanosomes within barbules, but by periodic matrices of air and β-keratin within barbs. Lepidothrix iris crown feathers were able to produce a dazzling display of colours with small shifts in viewing geometry, likely because of a periodic nanostructure, a flattened barb morphology and disorder at a microstructural level. We hypothesize that iridescent plumage ornaments of male L. iris and L. nattereri are under selection to increase brightness or luminance across wide viewing angles, which may potentially increase their detectability by females during dynamic and fast-paced courtship displays in dim light environments.
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Affiliation(s)
- Branislav Igic
- Department of Biology, The University of Akron, Akron, OH 44325, USA
| | - Liliana D'Alba
- Department of Biology, The University of Akron, Akron, OH 44325, USA
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