Butterfly Wing Research Articles

Frizzled2 receives WntA signaling during butterfly wing pattern formation.

Butterfly color patterns provide visible and biodiverse phenotypic readouts of the patterning processes. Although the secreted ligand WntA has been shown to instruct the color pattern formation in butterflies, its mode of reception remains elusive. Butterfly genomes encode four homologs of the Frizzled-family of Wnt receptors. Here, we show that CRISPR mosaic knockouts of frizzled2 (fz2) phenocopy the color pattern effects of WntA loss of function in multiple nymphalids. Whereas WntA mosaic clones result in intermediate patterns of reduced size, fz2 clones are cell-autonomous, consistent with a morphogen function. Shifts in expression of WntA and fz2 in WntA crispant pupae show that they are under positive and negative feedback, respectively. Fz1 is required for Wnt-independent planar cell polarity in the wing epithelium. Fz3 and Fz4 show phenotypes consistent with Wnt competitive-antagonist functions in vein formation (Fz3 and Fz4), wing margin specification (Fz3), and color patterning in the Discalis and Marginal Band Systems (Fz4). Overall, these data show that the WntA/Frizzled2 morphogen-receptor pair forms a signaling axis that instructs butterfly color patterning and shed light on the functional diversity of insect Frizzled receptors.

Anti-reflective properties of butterfly-wing-micro-nano structures in the infrared band

The delicate and intricate micro-nano structure on the surface of butterfly wings is genuinely remarkable. Despite its potential for anti-reflection purposes, this surface structure's theoretical analysis, optimal design, and anti-reflection performance regulation remain a mystery. The anti-reflection characteristics of butterfly Papilio epiphorbas, butterfly Parthenos syvia, and butterfly Sasakia charonda butterfly wings in the infrared band were carefully examined using finite difference time domain simulation and equivalent medium theoretical calculation. The anti-reflection mechanism of the surface micro-nano structure parameters and infrared wavelength of the butterfly wings of butterfly Papilio epiphorbas, butterfly Parthenos syvia, and butterfly Sasakia charonda were revealed. By Fourier infrared reflectance test and simulation of the three butterfly wings, the results show that the structural color scales of the three butterfly wings can achieve a better anti-reflection effect in the infrared band. The anti-reflection performance of the extracted bionic butterfly wings is improved by 0.34%, 2.44%, and 5.46%, respectively, compared with the original butterfly wings. These findings provide valuable theoretical and data support for the continued development of the design and manufacture of bionic anti-reflective surface optics.

Live Detection of Intracellular Chitin in Butterfly Wing Epithelial Cells In Vivo Using Fluorescent Brightener 28: Implications for the Development of Scales and Color Patterns.

Chitin is the major component of the extracellular cuticle and plays multiple roles in insects. In butterflies, chitin builds wing scales for structural colors. Here, we show that intracellular chitin in live cells can be detected in vivo with fluorescent brightener 28 (FB28), focusing on wing epithelial cells of the small lycaenid butterfly Zizeeria maha immediately after pupation. A relatively small number of cells at the apical surface of the epithelium were strongly FB28-positive in the cytosol and seemed to have extensive ER-Golgi networks, which may be specialized chitin-secreting cells. Some cells had FB28-positive tadpole-tail-like or rod-like structures relative to the nucleus. We detected FB28-positive hexagonal intracellular objects and their associated structures extending toward the apical end of the cell, which may be developing scale bases and shafts. We also observed FB28-positive fibrous intracellular structures extending toward the basal end. Many cells were FB28-negative in the cytosol, which contained FB28-positive dots or discs. The present data are crucial to understanding the differentiation of the butterfly wing epithelium, including scale formation and color pattern determination. The use of FB28 in probing intracellular chitin in live cells may be applicable to other insect systems.

IMPLEMENTASI DIMENSI FRAKTAL BOX COUNTING DAN K-MEANS DALAM KLASIFIKASI JENIS KUPU-KUPU (LEPIDOPTERA) BERDASARKAN BENTUK SAYAP

Butterflies are insects that have aesthetic beauty and are also important assets in the field of nature protection. In nature, butterflies have a crucial role in maintaining ecosystems, especially in the process of pollination of flowering plants which contributes to the natural propagation of plants. Butterfly wings have an important role in identifying butterfly species based on size, shape and color. In mathematics, there is the concept of fractals which is a very suitable method for modeling natural phenomena and used as a tool to represent natural objects. In this study, a classification of butterfly species was carried out based on the shape of the butterfly's wings. A total of 100 butterfly images were used in this study, the first step was to convert the RGB images to grayscale and then segment the butterfly wings. The area is then used to identify butterfly wing type patterns using edge detection using the Canny method. Furthermore, by using the fractal box counting method, the resulting dimensional values are used in the clustering process. The results of the dimension values will be classified using the K-Means grouping method with five groups, namely Adonis Butterfly, Julia Butterfly, Brown Siproeta Butterfly, Metal Marks Butterfly, and African Giant Swallowtail Butterfly, showing an accuracy of 89%.

Bio-inspired dual-responsive photonic crystal with smart responsive hydrogel for pH and temperature detection

Responsive photonic crystals (PCs) with bio-inspired microstructures and tailorable functionalities are of critical importance for their potential applications in diverse fields such as biological detection, sensing, decoration, anti-counterfeiting, etc. However, limited by preparation technologies and design theories, it is still a challenge to accurately and uniformly deposit smart responsive materials on natural PC structures and achieve dual stimulus response. Herein, a simple and rapid in situ polymerization method is presented for preparing dual-responsive PCs with ultra-precise micro-/nanoscale hierarchical structures. Exposure of the reaction site by deacetylation of Morpho butterfly wings allows in situ polymerisation of poly (N-isopropylacrylamide-co-acrylic acid) (P(NIPAAM-co-AAc)) on the surface of the natural photonic structure. The obtained P(NIPAAM-co-AAc) photonic crystals (P(NIPAAM-co-AAc)-PCs) exhibited a dual response to pH and temperature reversibility. In addition, the synergistic effect of the structures and materials on the optical response of the natural PCs is revealed. This work allows the combination of natural hierarchical PC structures with smart hydrogel to achieve an optical response to pH and temperature, thus opening up the channels for responsive PC to multiple stimulus responses.

Breeding Polyommatus icarus Serves as a Large-Scale and Environmentally Friendly Source of Precisely Tuned Photonic Nanoarchitectures.

The colour of the butterfly wing serves as an important sexual and species-specific signal. Some species produce structural colouration by developing wing scales with photonic nanoarchitectures. These nanostructures are highly conservative, allowing only a ±10 nm peak wavelength deviation in the reflectance spectra of the blue structural colour in natural Common Blue (Polyommatus icarus) populations. They are promising templates of future artificial photonic materials and can be used in potential applications, too. In this work, we present methodology and infrastructure for breeding laboratory populations of Common Blue as a cost-effective and environmentally friendly source of nanostructures. Our technology enables the production of approximately 7500 wing samples, equivalent to 0.5-1 m2 of photonic nanoarchitecture surface within a year in a single custom-made insectarium. To ascertain the reliability of this method, we compared reflectance properties between different populations from distant geographic locations. We also provide genetic background of these populations using microsatellite genotyping. The laboratory population showed genetic erosion, but even after four generations of inbreeding, only minimal shifts in the structural colouration were observed, indicating that wild Common Blue populations may be a reliable source of raw material for photonic surfaces.

New molecular insights into butterfly pigmentation

Hanly etal.1 and Nishida etal.2 use distinct approaches to provide exceptional lessons regarding the genetic, molecular, morphological, and biochemical bases of butterfly wing pigmentation. These mechanistic insights collectively have important implications for our understanding of phenotype evolution.

Spatial and temporal regulation of Wnt signaling pathway members in the development of butterfly wing patterns.

Wnt signaling members are involved in the differentiation of cells associated with eyespot and band color patterns on the wings of butterflies, but the identity and spatio-temporal regulation of specific Wnt pathway members remains unclear. Here, we explore the localization and function of Armadillo/β-catenin dependent (canonical) and Armadillo/β-catenin independent (noncanonical) Wnt signaling in eyespot and band development in Bicyclus anynana by localizing Armadillo (Arm), the expression of all eight Wnt ligand and four frizzled receptor transcripts present in the genome of this species and testing the function of some of the ligands and receptors using CRISPR-Cas9. We show that distinct Wnt signaling pathways are essential for eyespot and band patterning in butterflies and are likely interacting to control their active domains.

Potential Large-area Imaging of Butterfly Wing Scales with Transmission Electron Microscopy.

Potential Large-area Imaging of Butterfly Wing Scales with Transmission Electron Microscopy.

Topological butterfly wings for human induced pluripotent stem cell-derived cardiomyocyte maturation and myocardial infarction treatment

Myocardial infarction (MI) causes irreversible myocardial cell loss; however, current treatments are limited to slowing disease progression rather than restoring lost myocardium. Cardiac tissue engineering, based on inexhaustible human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), becomes an ideal treatment method for supplying exogenous cardiomyocytes (CMs) to help contractile function recovery. However, hiPSC-CMs currently used are usually immature, which might trigger ventricular arrhythmias in MI treatments and limit their application in myocardial tissue engineering. The topological structure, as one of the most effective cues in controlling cellular functions, may benefit hiPSC-CM maturation. Here, the natural topological Morpho Menelaus butterfly wings (BFW) were chosen to regulate hiPSC-CM maturation and form the grafts for MI treatment. Immunofluorescence and calcium imaging tests confirmed that the parallel nanoridges on the surface of BFW oriented cellular growth and enhanced gap junction formation and improved the calcium handling ability of hiPSC-CMs, which demonstrated the maturation of hiPSC-CMs. BFW-matured hiPSC-CMs were transplanted as a patch for MI treatment evaluation, and twenty-eight days after engraftment, the histological destruction and contractile function of MI mice were improved obviously. This work provides an effective method for promoting hiPSC-CM maturation and potentially expands the application of natural materials in myocardial tissue engineering.

Rational Design and Fabrication Method for Bioinspired Directional Droplet Sliding Surfaces

AbstractA rational design and fabrication method is proposed for fabricating polymeric directional droplet sliding surfaces inspired by butterfly wing microline arrays. The bioinspired structures are fabricated using a simple and well‐designed process that combines the conventional micro‐electromechanical system process with subsequent soft lithography. Three criteria to avoid fabrication errors during silicon mold production are suggested. The fabricated silicon master serves as a reliable and robust semi‐permanent mold for polymeric replication, resulting in bioinspired surfaces with high fidelity. The successfully fabricated bioinspired fabricated structure surface has a re‐entrant shape line structure and exhibits directional omniphobic properties while maintaining transparency. The fabricated surface is found to transport droplets in the direction where microlines are formed without wetting by various droplets, including water and oil. The results show that this surface can be applied to various fields. This study has implications for the development of artificial surfaces inspired by nature for various fields, including microfluidics, biotechnology, and energy‐harvesting devices.

Large-scale spatial variation and phenotypic integration in three Argynnini species inform about functions and evolutionary drivers of butterfly wings

Understanding how large-scale environmental variability may shape the distribution of phenotypic variation remains central to evolutionary biology. Across-species comparisons of trait variation alongside environmental gradients may offer valuable insights into how different species may respond to similar selective pressures. We conducted a comparative morphological study (>32° latitude and >47° longitude) on three closely related Argynnini butterfly species, Speyeria aglaja, Fabriciana adippe, and F. niobe. We measured wing size and coloration to assess (1) whether they respond similarly or differently to environmental factors (longitude, latitude, altitude, temperature, precipitation, solar radiation, wind speed); (2) if these factors correspond with those associated with the species’ genetic structure based on a previous study; and (3) whether correlations between phenotypic traits within individuals are species-specific. We found common and species-specific associations of climatic (precipitation, wind speed) and geographic (longitude, altitude) factors with the composite phenotypic variation. Wing size was associated with different variables in the studied species, while melanisation mainly increased in cooler regions in all species, suggesting that the need for temperature regulation is a strong selective pressure on melanisation. Wing size was associated with the genetic structure in all species, highlighting the functional importance of this trait. The environmental drivers associated with the phenotypic variation in S. aglaja and F. adippe were largely the same as those associated with their genetic structure, hinting at a genetic underpinning of the observed morphological variation due to local adaption. We report some distinct intraspecific trait correlations in S. aglaja and F. adippe, indicative of independent phenotypic integration. These phenotypes seem to be associated with protection against predators and thermal regulation in the respective habitats of both species, suggesting that similar selective pressures have resulted in the evolution of different trait combinations. Some of the inter-specific differences could be related to diverging niche breadths and dispersal capacities, exemplifying that the evolution of trait integration and spatial phenotypic differentiation may differ between closely related species with overlapping distribution ranges. Our findings highlight the importance of comparative assessments of variation, and demonstrate that the relative effects of drivers of variability may vary between sister species.

Leucopterin, the white pigment in butterfly wings: structural analysis by PDF fit, FIDEL fit, Rietveld refinement, solid-state NMR and DFT-D.

Leucopterin (C6H5N5O3) is the white pigment in the wings of Pieris brassicae butterflies, and other butterflies; it can also be found in wasps and other insects. Its crystal structure and its tautomeric form in the solid state were hitherto unknown. Leucopterin turned out to be a variable hydrate, with 0.5 to about 0.1 molecules of water per leucopterin molecule. Under ambient conditions, the preferred state is the hemihydrate. Initially, all attempts to grow single crystals suitable for X-ray diffraction were to no avail. Attempts to determine the crystal structure by powder diffraction using the direct-space method failed, because the trials did not include the correct, but rare, space group P2/c. Attempts were made to solve the crystal structure by a global fit to the pair distribution function (PDF-Global-Fit), as described by Prill and co-workers [Schlesinger et al. (2021). J. Appl. Cryst. 54, 776-786]. The approach worked well, but the correct structure was not found, because again the correct space group was not included. Finally, tiny single crystals of the hemihydrate could be obtained, which allowed at least the determination of the crystal symmetry and the positions of the C, N and O atoms. The tautomeric state of the hemihydrate was assessed by multinuclear solid-state NMR spectroscopy. 15N CPMAS spectra showed the presence of one NH2 and three NH groups, and one unprotonated N atom, which agreed with the 1H MAS and 13C CPMAS spectra. Independently, the tautomeric state was investigated by lattice-energy minimizations with dispersion-corrected density functional theory (DFT-D) on 17 different possible tautomers, which also included the prediction of the corresponding 1H, 13C and 15N chemical shifts in the solid. All methods showed the presence of the 2-amino-3,5,8-H tautomer. The DFT-D calculations also confirmed the crystal structure. Heating of the hemihydrate results in a slow release of water between 130 and 250 °C, as shown by differential thermal analysis and thermogravimetry (DTA-TG). Temperature-dependent powder X-ray diffraction (PXRD) showed an irreversible continuous shift of the reflections upon heating, which reveals that leucopterin is a variable hydrate. This observation was also confirmed by PXRD of samples obtained under various synthetic and drying conditions. The crystal structure of a sample with about 0.2 molecules of water per leucopterin was solved by a fit with deviating lattice parameters (FIDEL), as described by Habermehl et al. [Acta Cryst. (2022), B78, 195-213]. A local fit, starting from the structure of the hemihydrate, as well as a global fit, starting from random structures, were performed, followed by Rietveld refinements. Despite dehydration, the space group remains P2/c. In both structures (hemihydrate and variable hydrate), the leucopterin molecules are connected by 2-4 hydrogen bonds into chains, which are connected by further hydrogen bonds to neighbouring chains. The molecular packing is very efficient. The density of leucopterin hemihydrate is as high as 1.909 kg dm-3, which is one of the highest densities for organic compounds consisting of C, H, N and O only. The high density might explain the good light-scattering and opacity properties of the wings of Pieris brassicae and other butterflies.

Cross-Scale Light Absorption Properties of Surface Bionic Microstructures for Spacecraft Stealth

To address the problem that the black coating for spacecraft optical stealth easily falls off, this study constructs a light-absorbing spacecraft surface based on a micro/nanostructure through imitating a natural light-trapping structure. In this paper, we first analyze the optical properties of a basic stealth structure with the finite difference time domain (FDTD) method and establish a mapping relationship between the light absorption rate of the basic stealth structure and its multiscale factors. Then, imitating the microstructural characteristics of the blackened parts of butterfly wings, we design a multilayered and multiscale complex stealth structure to achieve the optical stealth characteristics of low reflection and high absorption of sunlight on the surface of the spacecraft. Simulation analysis shows that the bionic microstructure can be used to change the optical properties of the metal surface to a certain wavelength band; the complex stealth structure designed based on the butterfly wing can absorb 80.18% of visible light and reduce the overall brightness of the high-orbiting spacecraft by four orders of magnitude.

Confirming Debonding of Non-Metallic Inclusions as an Important Factor in Damage Initiation in Bearing Steel

Damage in bearings is closely associated with the presence of microstructural alterations, known as white etching areas (WEAs) and white etching cracks (WECs). One of the main reasons for the creation of these microstructural alterations is the presence of defects in the material, such as non-metallic inclusions. Manganese sulfides and aluminum oxides are widely reported in the literature as the most common types of non-metallic inclusions found in bearing steels. This study classifies 280 non-metallic inclusions in an investigated bearing steel according to several criteria: bonded/debonded with the matrix, size, shape, orientation angle, depth below the raceway surface, and chemical composition. Contrary to the findings in the literature, this investigation reports that the chemical composition of the inclusion (MnS + Al2O3) is of secondary importance when considering factors for damage initiation. The orientation of the microstructural alterations is observed to coincide with the high-stress regions, indicating a relation between the formation of butterfly wings and the white etching crack. In our investigation, butterfly wings typically exhibit a 45-degree pattern originating from the non-metallic inclusions. Conversely, the white etching crack starts from the non-metallic inclusion at a shallower angle in correspondence to the raceway. This can be attributed to the stress state, which corresponds to a region where extensive white etching cracks are formed. In conclusion, the microstructural observations demonstrate that the state of non-metallic inclusion—i.e., whether they are bonded or not to the steel matrix—plays an essential role in initiating rolling contact fatigue damage.

Vermilion and cinnabar are involved in ommochrome pigment biosynthesis in eyes but not wings of Bicyclus anynana butterflies

If the same pigment is found in different tissues in a body, it is natural to assume that the same metabolic pathways are deployed similarly in each tissue. Here we show that this is not the case for ommochromes, the red and orange pigments found in the eyes and wings of butterflies. We tested the expression and function of vermilion and cinnabar, two known fly genes in the ommochrome pathway, in the development of pigments in the eyes and in the wings of Bicyclus anynana butterflies, both traits having reddish/orange pigments. By using fluorescent in-situ hybridization (HCR3.0) we localized the expression of vermilion and cinnabar in the cytoplasm of pigment cells in the ommatidia but observed no clear expression for either gene on larval and pupal wings. We then disrupted the function of both genes, using CRISPR-Cas9, which resulted in the loss of pigment in the eyes but not in the wings. Using thin-layer chromatography and UV–vis spectroscopy we identified the presence of ommochrome and ommochrome precursors in the orange wing scales and in the hemolymph of pupae. We conclude that the wings either synthesize ommochromes locally, with yet unidentified enzymes or incorporate these pigments synthesized elsewhere from the hemolymph. Different metabolic pathways or transport mechanisms, thus, lead to the presence of ommochromes in the wings and eyes of B. anynana butterflies.

Valide Tests zur Erstellung eines Assessments zum Screening für Risikofaktoren von Verletzungen der unteren Extremität in Mannschaftsballsportarten

In this paper, a novel butterfly wing type hydrocarbon fuel cooling channel structure is proposed and applied for the first time in the cooling of rotating power generation turbine blades of hypersonic vehicles. The effects of rotating butterfly wing-type channel root height and cross-critical temperature on the friction factor and heat transfer performance of hydrocarbon fuel are investigated in depth. Numerical results show that the thermal performance of the butterfly wing type channel corresponding to the root height of 0.8 D is the highest. Compared to the 1 D channel, the thermal performance of the butterfly wing type channel corresponding to the root height of 0.8 D is increased by a maximum of 1.8 times. Compared to the 1 D channel, the Nusselt number of the wing type channel corresponding to the root height 0.2 D is increased by a maximum of 1.03 times. Compared to the inlet temperature greater than critical temperature, the thermal performance of the wing type channel at inlet temperature less than critical temperature is increased by a maximum of 2.1 times. Compared to the 1 D channel, the wing type channel reduces the first channel backflow and vortex area by almost 50%.

Novel butterfly wing type rotating channel supercritical pressure hydrocarbon fuel heat transfer performance investigation

In this paper, a novel butterfly wing type hydrocarbon fuel cooling channel structure is proposed and applied for the first time in the cooling of rotating power generation turbine blades of hypersonic vehicles. The effects of rotating butterfly wing-type channel root height and cross-critical temperature on the friction factor and heat transfer performance of hydrocarbon fuel are investigated in depth. Numerical results show that the thermal performance of the butterfly wing type channel corresponding to the root height of 0.8 D is the highest. Compared to the 1 D channel, the thermal performance of the butterfly wing type channel corresponding to the root height of 0.8 D is increased by a maximum of 1.8 times. Compared to the 1 D channel, the Nusselt number of the wing type channel corresponding to the root height 0.2 D is increased by a maximum of 1.03 times. Compared to the inlet temperature greater than critical temperature, the thermal performance of the wing type channel at inlet temperature less than critical temperature is increased by a maximum of 2.1 times. Compared to the 1 D channel, the wing type channel reduces the first channel backflow and vortex area by almost 50%.

A Novel Ultra-Wideband Electromagnetic-Wave-Absorbing Metastructure Inspired by Bionic Gyroid Structures.

Traditional honeycomb-like structural electromagnetic (EM)-wave-absorbing materials have been widely used in various equipment as multifunctional materials. However, current EM-wave-absorbing materials are limited by narrow absorption bandwidths and incidence angles because of their anisotropic structural morphology. The work presented here proposes a novel EM-wave-absorbing metastructure with an isotropic morphology inspired by the gyroid microstructures seen in Parides sesostris butterfly wings. A matching redesign methodology between the material and subwavelength scale properties of the gyroid microstructure is proposed, inspired by the interaction mechanism between the microstructure and the material properties on the EM-wave-absorption performance of the prepared metastructure. The bioinspired metastructure is fabricated by additive manufacturing (AM) and subsequent coating through dipping processes, filled with dielectric lossy materials. Based on simulations and experiments, the metastructure designed in this work exhibits an ultrawide absorption bandwidth covering the frequency range of 2-40GHz with a fractional bandwidth of 180% at normal incidence. Moreover, the metastructure has a stable frequency response when the incident angle is 60° under transverse electric (TE) and transverse magnetic (TM) polarization. Finally, the synergistic mechanism between the microstructure and the material is elucidated, which provides a new paradigm for the design of novel ultra-broadband EM-absorbing materials.

Investigating the Effect of Reflectance Tuning on Photocatalytic Dye Degradation with Biotemplated ZnO Photonic Nanoarchitectures Based on Morpho Butterfly Wings.

Photonic nanoarchitectures of butterfly wings can serve as biotemplates to prepare semiconductor thin films of ZnO by atomic layer deposition. The resulting biotemplated ZnO nanoarchitecture preserves the structural and optical properties of the natural system, while it will also have the features of the functional material. The ZnO-coated wings can be used directly in heterogeneous photocatalysis to decompose pollutants dissolved in water upon visible light illumination. We used the photonic nanoarchitectures of different Morpho butterflies with different structural colors as biotemplates and examined the dependence of decomposition rates of methyl orange and rhodamine B dyes on the structural color of the biotemplates and the thickness of the ZnO coating. Using methyl orange, we measured a ten-fold increase in photodegradation rate when the 20 nm ZnO-coated wings were compared to similarly coated glass substrates. Using rhodamine B, a saturating relationship was found between the degradation rate and the thickness of the deposited ZnO on butterfly wings. We concluded that the enhancement of the catalytic efficiency can be attributed to the slow light effect due to a spectral overlap between the ZnO-coated Morpho butterfly wings reflectance with the absorption band of dyes, thus the photocatalytic performance could be changed by the tuning of the structural color of the butterfly biotemplates. The photodegradation mechanism of the dyes was investigated by liquid chromatography-mass spectroscopy.