1. Distal-less activates butterfly eyespots consistent with a reaction diffusion process
- Author
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Timothy E. Saunders, Tirtha Das Banerjee, Heidi Connahs, Tricia Y. J. Loo, Sham Tlili, Antónia Monteiro, and Jelle van Creij
- Subjects
0303 health sciences ,Wnt signaling pathway ,Bicyclus anynana ,Biology ,biology.organism_classification ,Phenotype ,Exon skipping ,03 medical and health sciences ,Exon ,0302 clinical medicine ,Evolutionary biology ,Eyespot ,CRISPR ,Molecular Biology ,030217 neurology & neurosurgery ,Function (biology) ,030304 developmental biology ,Developmental Biology - Abstract
Eyespots on the wings of nymphalid butterflies represent colorful examples of pattern formation, yet the developmental origins and mechanisms underlying eyespot center differentiation are still poorly understood. Using CRISPR-Cas9 we re-examine the function of Distal-less (Dll) as an activator or repressor of eyespots, a topic that remains controversial. We show that the phenotypic outcome of CRISPR mutations depends upon which specific exon is targeted. In Bicyclus anynana, exon 2 mutations are associated with both missing and ectopic eyespots, and also exon skipping. Exon 3 mutations, which do not lead to exon skipping, produce only null phenotypes, including missing eyespots, lighter wing coloration and loss of scales. Reaction-diffusion modeling of Dll function, using Wnt and Dpp as candidate morphogens, accurately replicates these complex crispant phenotypes. These results provide new insight into the function of Dll as a potential activator of eyespot development, scale growth and melanization, and suggest that the tuning of Dll expression levels can generate a diversity of eyespot phenotypes, including their appearance on the wing.This article has an associated 'The people behind the papers' interview.
- Published
- 2019