Retention and losses of ultraviolet-sensitive visual pigments in bats

Longfei Li,Haonan Liu,Yu Xia,Shuyi Zhang,Yang Liu,David M Irwin,Hai Chi

doi:10.1038/s41598-018-29646-6

Longfei Li, Haonan Liu + Show 5 more

Open Access

https://doi.org/10.1038/s41598-018-29646-6

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Abstract

Ultraviolet (UV)-sensitive visual pigment and its corresponding ability for UV vision was retained in early mammals from their common ancestry with sauropsids. Subsequently, UV-sensitive pigments, encoded by the short wavelength-sensitive 1 (SWS1) opsin gene, were converted to violet sensitivity or have lost function in multiple lineages during the diversification of mammals. However, many mammalian species, including most bats, are suggested to retain a UV-sensitive pigment. Notably, some cave-dwelling fruit bats and high duty cycle echolocating bats have lost their SWS1 genes, which are proposed to be due to their roosting ecology and as a sensory trade-off between vision and echolocation, respectively. Here, we sequenced SWS1 genes from ecologically diverse bats and found that this gene is also non-functional in both common vampire bat (Desmodus rotundus) and white-winged vampire bat (Diaemus youngi). Apart from species with pesudogenes, our evolutionary and functional studies demonstrate that the SWS1 pigment of bats are UV-sensitive and well-conserved since their common ancestor, suggesting an important role across major ecological types. Given the constrained function of SWS1 pigments in these bats, why some other species, such as vampire bats, have lost this gene is even more interesting and needs further investigation.

Highlights

Ultraviolet (UV)-sensitive visual pigment and its corresponding ability for UV vision was retained in early mammals from their common ancestry with sauropsids
The short wavelength-sensitive 1 (SWS1) gene was lost in the ancestor of monotremes, the only mammalian group that possesses a functional short wavelength-sensitive 2 (SWS2) opsin gene, after their split from therians[5]
Sequences from three (Cynopterus sphinx, Megaderma spasma and Rhinopoma hardwickii) of the eight species come from three different families of the suborder Yinpterochiroptera, while the other five species (Chaerephon plicatus, Miniopterus fuliginosus, Pipistrellus abramus, Leptonycteris yerbabuenae and Artibeus lituratus) are from four families of the suborder Yangochiroptera

Summary

Introduction

Ultraviolet (UV)-sensitive visual pigment and its corresponding ability for UV vision was retained in early mammals from their common ancestry with sauropsids. We sequenced the complete SWS1 coding regions from several ecologically diverse bat species, expressed these opsins, and determined the spectral sensitivities of the visual pigments to study the roles of bat SWS1 pigments and provide a functional supplement to the mammalian SWS1 pigments.

Results

Conclusion