Diverse set of Turing nanopatterns coat corneae across insect lineages

Abstract

Nipple-like nanostructures covering the corneal surfaces of moths, butterflies, and Drosophila have been studied by electron and atomic force microscopy, and their antireflective properties have been described. In contrast, corneal nanostructures of the majority of other insect orders have either been unexamined or examined by methods that did not allow precise morphological characterization. Here we provide a comprehensive analysis of corneal surfaces in 23 insect orders, revealing a rich diversity of insect corneal nanocoatings. These nanocoatings are categorized into four major morphological patterns and various transitions between them, many, to our knowledge, never described before. Remarkably, this unexpectedly diverse range of the corneal nanostructures replicates the complete set of Turing patterns, thus likely being a result of processes similar to those modeled by Alan Turing in his famous reaction−diffusion system. These findings reveal a beautiful diversity of insect corneal nanostructures and shed light on their molecular origin and evolutionary diversification. They may also be the first-ever biological example of Turing nanopatterns.nanocoating | cornea | insects | nanostructures | Turing

Patrones en la naturaleza: más que un diseño inspirador

“…Another interesting attribute of Turing patterns is that they can be obtained on a wide variety of scales ranging from the nanoscale to the macroscopic scale. Patterns can be observed in leaves of plants and nano-Turing patterns were recently observed in the corneas of different arthropods (Blagodatski, et al, 2015), Figure 3a; microscopic analysis of corneas from different insect families showed that there is a certain correlation between families with similar evolutionary origins and the morphology of the observed pattern, enabling entomology to consider a new taxonomic criterion.…”

“…Thus, the presence of patterns in living beings can be indicators of their evolutionary history and their adaptability, as suggested by some recent studies (Blagodatski, et al, 2015). Regarding inert systems, pattern formation results in the design of efficient bio-inspired technologies, in particular the design of structured-surface solids with appropriate patterns for specific applications (Bensemann, et al, 2005) and the design of chemical processes that emulate organic systems of living beings, such as the respiratory and circulatory systems (Coppens, 2012) …”

It's Not a Bug, It's a Feature: Functional Materials in Insects

“…This is particularly true for insects living in low-light conditions, such as moths and other nocturnal insects, which feature similar nanopillars covering their facet lenses ( Figure 15C,D). [342][343][344][345] These so-called corneal nipple arrays optimize light flux into the eye and photon detection by the photoreceptors. As a positive side effect, the surface reflection of the eyes is minimized during daytime, suppressing a detectable reflection of the inactive insects by predators.…”

“…[332] Copyright 2014, Matteo Burresi. nanostructures ( Figure 15E) whose developmental pathway is unknown but is hypothesized to be based on a Turing-like patterning of the outermost corneal layer during development. [344] …”

Using synthetic biology to explore principles of development

“…1C). Turing systems are thought to underlie many different examples of developmental patterning, including mesendodermal and left-right organization (Müller et al, 2012), mammalian palatal rugal ridge formation (Economou et al, 2012), hair follicle spacing (Sick et al, 2006), finger formation (Raspopovic et al, 2014) and nano-features of insect cornea (Blagodatskia et al, 2015).…”