JAPANESE TOP Message from the Director Information Faculty list Research Cooperative Research Projects Entrance Exam Publication Job Vacancy INTERNSHIP PROGRAM Links Access HANDBOOK FOR INTERNATIONAL RESEARCHERS Map of Inuyama
BONOBO Chimpanzee "Ai" Crania photos Itani Jun'ichiro archives Open datasets for behavioral analysis Guidelines for Care and Use of Nonhuman Primates(pdf) Study material catalogue/database Guideline for field research of non-human primates 2019(pdf) Primate Genome DB

Primate Research Institute, Kyoto University
Inuyama, Aichi 484-8506, JAPAN
TEL. +81-568-63-0567
(Administrative Office)
FAX. +81-568-63-0085

Copyright (c)
Primate Research Institute,
Kyoto University All rights reserved.



Vertebrate Rhodopsin Adaptation to Dim Light via Rapid Meta-II Intermediate Formation

Tohru Sugawara, Hiroo Imai, Masato Nikaido, Yasushi Imamoto, and Norihiro Okada

Rhodopsin is a photoreceptive protein present in vertebrate rod photoreceptor cells, which are responsible for scotopic vision. Recent molecular studies have shown that several aquatic vertebrate species have independently acquired rhodopsin containing Asp83Asn, Glu122Gln and Ala292Ser substitutions, causing a blue-shift in the rhodopsin absorption spectra for adaptation to the blue-green photic environment in deep water. Here, we provide new evidence for the evolutionary and functional relevance of the Asp83Asn substitution. Spectroscopic and kinetic analyses of rhodopsins in six cichlid fishes from the East African Great Lakes using charge-coupled device spectrophotometer revealed that the Asp83Asn substitution accelerated formation of meta-II, a rhodopsin intermediate crucial for activation of the G-protein transducin. Because rapid formation of meta-II likely results in effective transduction of photic signals, it is reasonable to assume that deep-water cichlid species have acquired rhodopsin containing Asn83 to adapt to dim lighting. Remarkably, rhodopsin containing Asn83 has been identified in terrestrial vertebrates such as bats, and these rhodopsin variants also exhibit accelerated meta-II formation. Our results indicated that the Asp83Asn substitution observed in a variety of animal species was acquired independently in many different lineages during vertebrate evolution for adaptation to dimly lit environments.

Molecular Biology and Evolution


Copyright(C) 2009 PRI (). All rights reserved.