A role of color vision in emmetropization in C57BL/6J mice

Jinglei Yang,Yue Liu,Li Yang,Xueqin Hou,Jia Qu,Qiongsi Wang,Rongfang Chen,Xiangtian Zhou,Yun Zhu,Siyao Wang,Bei Wei

doi:10.1038/s41598-020-71806-0

Abstract

Spectral composition affects emmetropization in both humans and animal models. Because color vision interacts the effects of chromatic defocus, we developed a method to bypass the effects of longitudinal chromatic aberration by placing a spectral filter behind the optics of the eye, using genetic tools. Newborn C57BL/6J (B6) mice were reared in quasi-monochromatic red (585–660 nm) or blue (410–510 nm) light beginning before eye-opening. Refractive states and ocular dimensions were compared at 4, 6, 8, and 10 weeks with mice reared in normal white light. Cre recombinase-dependent Ai9 reporter mice were crossed with Chx10-Cre to obtain Chx10-Cre;Ai9 mice, expressing red fluorescent protein in retinal Cre-positive cells. Ai9 offsprings, with and without Cre, were reared under a normal visual environment. Refraction and axial components were measured as described above. Expression levels of M and S opsin were quantified by western blotting at 10 weeks. Compared with those reared in white light, B6 mice reared in red light developed relative hyperopia, principally characterized by flattening of corneal curvature. Emmetropization was not affected by blue light, possibly because the reduction in vitreous chamber depth compensated for the increase in corneal curvature. Compared with Cre-negative littermates, the refraction and axial dimensions of Chx10-Cre;Ai9 mice were not significantly different at the follow-up timepoints. M opsin levels were higher in Chx10-Cre;Ai9 mice at 10 weeks while S opsin levels were not different. Red light induced a hyperopic shift in mouse refractive development. Emmetropization was not impacted in mice with perturbed color vision caused by intrinsic red-fluorescent protein, suggesting that color vision may not be necessary in mouse emmetropization when other mechanisms are present.

Highlights

Myopia is the most common refractive abnormality in the world
Whether or not the color vision of the animal is involved in this process has not been addressed because in previous experimental setups, wavelength information was always mixed with the detection and decoding of chromatic signals by the sensory retina
We found that quasi-chromatic red light induced a hyperopic shift in emmetropization

Summary

Introduction

Myopia is the most common refractive abnormality in the world. The prevalence has increased significantly in recent decades as reported by numerous s tudies[1]. The second possibility is that emmetropization could use the relativity of the chromatic arrangement of lights as a cue In this case, if the long wavelengths are in better focus than the short wavelengths, the host animal could somehow identify the eye as myopic[23,30] and decrease the growth rate of axial development to achieve emmetropia. If the long wavelengths are in better focus than the short wavelengths, the host animal could somehow identify the eye as myopic[23,30] and decrease the growth rate of axial development to achieve emmetropia Until now, it has not been clear if and how color vision is involved in emmetropization, i.e., if it is the focus or color of the ambient environmental light that controls the refractive development and eye growth

Methods

Results

Conclusion