壁虎视觉色素的进化。

Evolution of visual pigments in geckos.

作者信息

Taniguchi Y, Hisatomi O, Yoshida M, Tokunaga F

机构信息

Department of Earth and Space Science, Graduate School of Science, Osaka University, Japan.

出版信息

FEBS Lett. 1999 Feb 19;445(1):36-40. doi: 10.1016/s0014-5793(99)00089-7.

DOI:10.1016/s0014-5793(99)00089-7

PMID:10069370

Abstract

Most geckos are nocturnal forms and possess rod retinas, but some diurnal genera have pure-cone retinas. We isolated cDNAs encoding the diurnal gecko opsins, dg1 and dg2, similar to nocturnal gecko P521 and P467, respectively. Despite the large morphological differences between the diurnal and nocturnal gecko photoreceptor types, they express phylogenetically closely related opsins. These results provide molecular evidence for the reverse transmutation, that is, rods of an ancestral nocturnal gecko have backed into cones of diurnal geckos. The amino acid substitution rates of dgl and dg2 are higher than those of P521 and P467, respectively. Changes of behavior regarding photic environment may have contributed to acceleration of amino acid substitutions in the diurnal gecko opsins.

摘要

大多数壁虎是夜行性的，拥有视杆视网膜，但一些日行性属具有纯视锥视网膜。我们分离出了编码日行性壁虎视蛋白dg1和dg2的cDNA，它们分别与夜行性壁虎的P521和P467相似。尽管日行性和夜行性壁虎光感受器类型在形态上有很大差异，但它们表达的视蛋白在系统发育上密切相关。这些结果为逆向演化提供了分子证据，即祖先夜行性壁虎的视杆细胞逆向演化为日行性壁虎的视锥细胞。dgl和dg2的氨基酸替换率分别高于P521和P467。关于光照环境的行为变化可能导致了日行性壁虎视蛋白中氨基酸替换的加速。