Schartau J Marcus, Sjögreen Bodil, Gagnon Yakir L, Kröger Ronald H H
Vision Group, Department of Cell and Organism Biology, Lund University, 223 62 Lund, Sweden.
Curr Biol. 2009 Jan 27;19(2):122-6. doi: 10.1016/j.cub.2008.11.062. Epub 2009 Jan 15.
One of the reasons that the crystalline lenses of vertebrate eyes are highly transparent is that most of the cells have broken down all of their organelles, including the nuclei. These cells can neither synthesize new proteins nor generate energy by electron transport in the mitochondria. Only in the peripheral layers--in the cichlid fish Aequidens pulcher, beyond 92% of the lens radius--are there cells with full complements of organelles. We report here that the optical properties of the lens change between the light-adapted and dark-adapted states in A. pulcher. Changes occur even in cell layers free of organelles, and they occur in parallel with changes in retinal function between the light-adapted (all-cone, color vision) and dark-adapted (all-rod, grayscale vision) states. Depleting the eye of dopamine also caused changes in the optical properties similar to those of dark adaptation. Our results indicate that the refractive index of the organelle-free lens fiber cells can be adjusted quickly and accurately.
脊椎动物眼睛的晶状体高度透明的原因之一是，大多数细胞已分解了所有细胞器，包括细胞核。这些细胞既不能合成新蛋白质，也无法通过线粒体中的电子传递产生能量。只有在外围层——在丽鱼科鱼类美丽栉丽鱼中，超过晶状体半径的92%处——才有细胞器完整的细胞。我们在此报告，美丽栉丽鱼晶状体的光学特性在明适应和暗适应状态之间会发生变化。即使在没有细胞器的细胞层中也会发生变化，并且这些变化与视网膜在明适应（全视锥细胞，彩色视觉）和暗适应（全视杆细胞，灰度视觉）状态之间的功能变化同时发生。去除眼睛中的多巴胺也会导致光学特性发生类似于暗适应的变化。我们的结果表明，无细胞器的晶状体纤维细胞的折射率可以快速而准确地调节。
