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Vertebrate vision is accomplished through light-sensitive photopigments consisting of an opsin protein bound to a chromophore. In dim light, vertebrates generally rely on a single rod opsin [rhodopsin 1 (RH1)] for obtaining visual information. By inspecting 101 fish genomes, we found that three deep-sea teleost lineages have independently expanded their RH1 gene repertoires. Among these, the silver spinyfin (Diretmus argenteus) stands out as having the highest number of visual opsins in vertebrates (two cone opsins and 38 rod opsins). Spinyfins express up to 14 RH1s (including the most blueshifted rod photopigments known), which cover the range of the residual daylight as well as the bioluminescence spectrum present in the deep sea. Our findings present molecular and functional evidence for the recurrent evolution of multiple rod opsin–based vision in vertebrates.
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Evolution of Opsin Genes in Caddisflies (Insecta: Trichoptera)
Abstract Insects have evolved complex and diverse visual systems in which light-sensing protein molecules called “opsins” couple with a chromophore to form photopigments. Insect photopigments group into three major gene families based on wavelength sensitivity: long wavelength (LW), short wavelength (SW), and ultraviolet wavelength (UV). In this study, we identified 123 opsin sequences from whole-genome assemblies across 25 caddisfly species (Insecta: Trichoptera). We discovered the LW opsins have the most diversity across species and form two separate clades in the opsin gene tree. Conversely, we observed a loss of the SW opsin in half of the trichopteran species in this study, which might be associated with the fact that caddisflies are active during low-light conditions. Lastly, we found a single copy of the UV opsin in all the species in this study, with one exception: Athripsodes cinereus has two copies of the UV opsin and resides within a clade of caddisflies with colorful wing patterns.
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- Award ID(s):
- 2217155
- PAR ID:
- 10540913
- Publisher / Repository:
- Oxford University Press
- Date Published:
- Journal Name:
- Genome Biology and Evolution
- Volume:
- 16
- Issue:
- 9
- ISSN:
- 1759-6653
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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