Wang Feng Yu, Tang Meng Yun, Yan Hong Young
Sensory Biology Laboratory, Marine Research Station, Institute of Cellular and Organismic Biology, Academia Sinica, Jiaoshi, I-Lan County 26242, Taiwan.
Vision Res. 2011 May 11;51(9):1099-108. doi: 10.1016/j.visres.2011.02.025. Epub 2011 Mar 6.
The goal of this study was to investigate how the eyes of different species of moray eel evolved to cope with limitations to vision imposed on them by the photic environments in which they reside. The comparative retinal histological structures and visual pigment characteristics including opsin gene sequences, of four species of moray eel inhabiting diverse habitats (i.e., shallow-water species, Rhinomuraena quaesita and Gymnothorax favagineus, and deep-sea species, Gymnothorax reticularis and Strophidon sathete) were examined. The histological sections showed that retinal layer structures of R. quaestia are significantly different from those of the other three species which likely reflects the effects of distribution depth on the structures. The maximal absorbance wavelength (λ(max)) of photoreceptor cells, as measured by microspectrophotometry (MSP), showed a close correlation between the λ(max) and the intensity/spectral quality of the light environment where each species lives. The spectra-shift, between shallow and deep-sea species, observed in the rods cells results from amino acid substitution in Rh1 gene, while that in cones most likely results from differential expression of multiple Rh2 genes.
本研究的目的是调查不同种类海鳝的眼睛如何进化，以应对其所处光环境对视觉造成的限制。研究人员检查了四种栖息于不同栖息地的海鳝（即浅水种类线纹裸胸鳝和黄边裸胸鳝，以及深海种类网纹裸胸鳝和锯尾蛇鳝）的视网膜组织学结构和视觉色素特征，包括视蛋白基因序列。组织学切片显示，线纹裸胸鳝的视网膜层结构与其他三种海鳝显著不同，这可能反映了分布深度对结构的影响。通过显微分光光度法（MSP）测量的光感受器细胞的最大吸收波长（λ(max)）表明，λ(max)与每种海鳝所处光环境的强度/光谱质量密切相关。在杆状细胞中观察到的浅海和深海种类之间的光谱位移是由Rh1基因中的氨基酸取代引起的，而锥状细胞中的光谱位移很可能是由多个Rh2基因的差异表达导致的。
