Hawryshyn C W, Hárosi F I
Laboratory of Sensory Physiology, Marine Biological Laboratory, Woods Hole, MA 02543.
Vision Res. 1994 Jun;34(11):1385-92. doi: 10.1016/0042-6989(94)90137-6.
We investigated retina preparations of young rainbow trout (Oncorhynchus mykiss) with body wt 5-40 g. Rods, single and double cones were measured in side-on orientation by microspectrophotometry, identifying five spectrally distinct visual pigments (or photoreceptors containing mixtures of visual pigments). The mean wavelength of peak absorbance (lambda max) of the alpha-bands were 365 and 434 nm in single cones, 531 and 576 nm in double cones, and 521 nm in the rods. The half-band width (HBW) of the main absorption bands were broader than expected of retinal- (vitamin A1-) based visual pigments, and thus, they were indicative of a mixed chromophore pool derived from both the vitamin A1 and A2 forms. One consequence of the utilization of mixed chromophores is the broadening of the alpha-band absorption in each pigment type. And yet, we obtained exceptionally narrow HBW for the UV-type pigment, when compared with HBW values expected on the basis of the linear trend seen in visual pigments absorbing in the visible spectrum. We conclude that the UV pigment in rainbow trout has an unusually narrow HBW. Nevertheless, this species is not exceptional in this regard, for the UV-absorbing visual pigments in other vertebrate species also have narrow HBW.
我们研究了体重为5 - 40克的幼年虹鳟（Oncorhynchus mykiss）的视网膜标本。通过显微分光光度法以侧视方向测量视杆细胞、单锥体细胞和双锥体细胞，鉴定出五种光谱上不同的视觉色素（或含有视觉色素混合物的光感受器）。单锥体细胞中α波段的最大吸收波长（λmax）的平均值为365和434纳米，双锥体细胞中为531和576纳米，视杆细胞中为521纳米。主要吸收带的半高宽（HBW）比基于视网膜（维生素A1）的视觉色素预期的要宽，因此，它们表明存在一个源自维生素A1和A2形式的混合发色团池。利用混合发色团的一个结果是每种色素类型中α波段吸收变宽。然而，与基于在可见光谱中吸收的视觉色素所呈现的线性趋势预期的HBW值相比，我们获得了紫外线型色素异常窄的HBW。我们得出结论，虹鳟中的紫外线色素具有异常窄的HBW。然而，在这方面该物种并非例外，因为其他脊椎动物物种中吸收紫外线的视觉色素也具有窄的HBW。
