School of Science and Technology, Nottingham Trent University, Nottingham, UK.
Department of Physiology and Biophysics, University of California Irvine, Irvine, CA, USA.
FASEB J. 2020 Apr;34(4):5552-5562. doi: 10.1096/fj.201902607R. Epub 2020 Feb 26.
The optics of the eye is the key to a functioning visual system. The exact nature of the correlation between ocular optics and eye development is not known because of the paucity of knowledge about the growth of a key optical element, the eye lens. The sophisticated optics of the lens and its gradient of refractive index provide the superior optical quality that the eye needs and which, it is thought, has a major influence on the development of proper visual function. The nature of a gradient refractive index lens, however, renders accurate measurements of its development difficult to make and has been the reason why the influence of lens growth on visual function remains largely unknown. Novel imaging techniques have made it possible to investigate growth of the eye lens in the zebrafish. This study shows measurements using X-ray Talbot interferometry of three-dimensional gradient index profiles in eye lenses of zebrafish from late larval to adult stages. The zebrafish lens shows evidence of a gradient of refractive index from the earliest stages measured and its growth suggests an apparent coincidence between periods of rapid increase in refractive index in the lens nucleus and increased expression of a particular crystallin protein group.
眼睛的光学特性是视觉系统正常运作的关键。由于对关键光学元件——晶状体——生长的了解甚少，因此尚不清楚眼球光学特性和眼睛发育之间的确切相关性。晶状体复杂的光学特性及其折射率梯度为眼睛提供了卓越的光学质量，人们认为这对正常视觉功能的发展有重大影响。然而，梯度折射率透镜的性质使得对其发育进行准确测量变得困难，这也是为什么透镜生长对视觉功能的影响在很大程度上仍然未知的原因。新型成像技术使得研究斑马鱼眼睛晶状体的生长成为可能。这项研究使用 X 射线泰伯干涉术测量了从晚期幼虫到成年阶段的斑马鱼眼睛晶状体的三维梯度折射率分布。研究表明，从最早测量的阶段开始，斑马鱼晶状体就表现出折射率梯度的迹象，其生长表明晶状体核中折射率快速增加的时期与特定晶体蛋白组表达增加之间存在明显的巧合。
