The actin cytoskeleton plays multiple roles in structural colour formation in butterfly wing scales

• Published in: Nature communications Vol. 15; no. 1; p. 4073
• Main Authors: Lloyd, Victoria J., Burg, Stephanie L., Harizanova, Jana, Garcia, Esther, Hill, Olivia, Enciso-Romero, Juan, Cooper, Rory L., Flenner, Silja, Longo, Elena, Greving, Imke, Nadeau, Nicola J., Parnell, Andrew J.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 20.05.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 14/1; 14/19; 14/63; 147/135; 147/143; 147/3; 631/1647/245/2226; 631/57/2268; 631/57/2282; Actin; Actin Cytoskeleton - metabolism; Actin Cytoskeleton - ultrastructure; Actins - metabolism; Animal Scales - metabolism; Animal Scales - ultrastructure; Animals; Butterflies & moths; Butterflies - metabolism; Butterflies - physiology; Butterflies - ultrastructure; Color; Cytoskeleton; Developmental stages; Humanities and Social Sciences; Morphology; multidisciplinary; Nanostructure; Pattern formation; Photonics; Pigmentation; Scanning electron microscopy; Scattering; Science; Science (multidisciplinary); Tomography; Wings; Wings, Animal - metabolism; Wings, Animal - ultrastructure
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-48060-3

Vivid structural colours in butterflies are caused by photonic nanostructures scattering light. Structural colours evolved for numerous biological signalling functions and have important technological applications. Optically, such structures are well understood, however insight into their development in vivo remains scarce. We show that actin is intimately involved in structural colour formation in butterfly wing scales. Using comparisons between iridescent (structurally coloured) and non-iridescent scales in adult and developing H. sara , we show that iridescent scales have more densely packed actin bundles leading to an increased density of reflective ridges. Super-resolution microscopy across three distantly related butterfly species reveals that actin is repeatedly re-arranged during scale development and crucially when the optical nanostructures are forming. Furthermore, actin perturbation experiments at these later developmental stages resulted in near total loss of structural colour in H. sara . Overall, this shows that actin plays a vital and direct templating role during structural colour formation in butterfly scales, providing ridge patterning mechanisms that are likely universal across lepidoptera. NCOMMS-23-44446C Vivid structural colours in butterflies are caused by photonic nanostructures scattering light, however insight into the development of such structures in vivo remains scarce. Here the authors show that actin plays a vital and direct templating role during structural colour formation in butterfly scales, providing ridge patterning mechanisms that are likely universal across lepidoptera.