Iridescent colors in feathers are some of the brightest in nature, and are produced by coherent light scattering from periodic arrangements of melanosomes (melanin-containing organelles). Hollow melanosomes, an evolutionary innovation largely restricted to birds, contain an optically powerful combination of high and low refractive indices (from the melanin and air, respectively) that enables production of brighter and more saturated colors than solid melanosomes. However, despite their significance to avian color and potential utility as optical biomaterials, little is known about the ontogeny of either the melanosomes themselves or the nanostructures they comprise. We used light and electron microscopy to characterize nanostructural development in regenerating feathers of wild turkeys, a species with iridescent color produced by a hexagonally close-packed array of hollow melanosomes. We found that melanosomes form as solid bodies in melanocytes. Later in development, largely after placement in developing barbules, their interiors dissolve and leave hollow cores. These now hollow melanosomes are initially disorganized in the barbule, but become close-packed as they are pulled to the edge of the barbule, likely through a combination of forces including depletion-attraction. These data suggest that these structurally colored tissues are self-assembled and represent novel pathways of development.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/jmor.20347 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Influence of Core Type and Shell Thickness on Avian-Inspired Structural Colors Produced from Melanin Nanoparticle Assemblies.
ACS Appl Mater Interfaces
September 2023
School of Polymer Science and Engineering, The University of Akron, Akron, Ohio 44325, United States.
Article Synopsis
- Hollow melanosomes in bird feathers produce vibrant structural colors due to the high refractive index contrast between melanin and air, inspiring studies on synthetic melanin nanoparticles for similar effects.* -
- Previous synthetic studies mostly focused on hollow nanoparticles with thin shells (<20 nm), although natural melanosomes can have shells as thick as 100 nm, prompting research on how shell thickness influences color.* -
- Using experimental and computational methods, the study finds that hollow particles with thin shells exhibit greater color saturation compared to solid or core-shell particles, which could have applications in various industries like paints and cosmetics.*
Unambiguous evidence of brilliant iridescent feather color from hollow melanosomes in an Early Cretaceous bird.
Natl Sci Rev
February 2022
Institute of Geology and Paleontology, Linyi University, China.
A unique form of melanosomes contributing to brilliant iridescent colors in modern bird feathers, previously unknown in fossil birds, is identified in the Early Cretaceous bird Eoconfuciusornis. The discovery highlights the complexity of plumage color nanostructures utilized early in bird evolution as far back as 130 million years ago.
View Article and Find Full Text PDFMorphogenesis of Iridescent Feathers in Anna's Hummingbird Calypte anna.
Integr Comp Biol
October 2021
Evolution and Optics of Nanostructures Group, Department of Biology, University of Ghent, Ledeganckstraat 35, Ghent 9000, Belgium.
Color is a phenotypic trait of utmost importance, particularly in birds, which are known for their diverse color signals and color-producing mechanisms including pigment-based colors, light scattering from nanostructured feather tissues and combinations thereof. Bright iridescent plumage colors of hummingbirds are caused by light scattering by an organized array of flattened, pigment organelles, containing air-filled vesicles, called melanosomes. These hollow platelets are organized in multilayer arrays that contain numerous sharp air/melanin refractive index interfaces, producing brilliant iridescent colors.
View Article and Find Full Text PDFFeather Gene Expression Elucidates the Developmental Basis of Plumage Iridescence in African Starlings.
J Hered
August 2021
Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY.
Iridescence is widespread in the living world, occurring in organisms as diverse as bacteria, plants, and animals. Yet, compared to pigment-based forms of coloration, we know surprisingly little about the developmental and molecular bases of the structural colors that give rise to iridescence. Birds display a rich diversity of iridescent structural colors that are produced in feathers by the arrangement of melanin-containing organelles called melanosomes into nanoscale configurations, but how these often unusually shaped melanosomes form, or how they are arranged into highly organized nanostructures, remains largely unknown.
View Article and Find Full Text PDFSignal evolution and morphological complexity in hummingbirds (Aves: Trochilidae).
Evolution
February 2020
Evolution and Optics of Nanostructures Group, Department of Biology, University of Ghent, 9000, Ghent, Belgium.
Understanding how animal signals are produced is critical for understanding their evolution because complexity and modularity in the underlying morphology can affect evolutionary patterns. Hummingbird feathers show some of the brightest and most iridescent colors in nature. These are produced by optically complex stacks of hollow, platelet-shaped organelles called melanosomes.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!