TY - JOUR
T1 - Cone visual pigments are present in gecko rod cells
AU - Kojima, Daisuke
AU - Okano, Toshiyuki
AU - Fukada, Yoshitaka
AU - Shichida, Yoshinori
AU - Yoshizawa, Tôru
AU - Ebrey, Thomas G.
PY - 1992
Y1 - 1992
N2 - The Tokay gecko (Gekko gekko), a nocturnal lizard, has two kinds of visual pigments, P467 and P521. In spite of the pure-rod morphology of the photoreceptor cells, the biochemical properties of P521 and P467 resemble those of iodopsin (the chicken red-sensitive cone visual pigment) and rhodopsin, respectively. We have found that the amino acid sequence of P521 deduced from the cDNA was very similar to that of iodopsin. In addition, P467 has the highest homology with the chicken green-sensitive cone visual pigment, although it also has a relatively high homology with rhodopsins. These results give additional strength to the transmutation theory of Walls [Walls, G. L. (1934) Am. J. Ophthalmol. 17, 892-915], who proposed that the rod-shaped photoreceptor cells of lizards have been derived from ancestral cone-like photoreceptors. Apparently amino acid sequences of visual pigments are less changeable than the morphology of the photoreceptor cells in the course of evolution.
AB - The Tokay gecko (Gekko gekko), a nocturnal lizard, has two kinds of visual pigments, P467 and P521. In spite of the pure-rod morphology of the photoreceptor cells, the biochemical properties of P521 and P467 resemble those of iodopsin (the chicken red-sensitive cone visual pigment) and rhodopsin, respectively. We have found that the amino acid sequence of P521 deduced from the cDNA was very similar to that of iodopsin. In addition, P467 has the highest homology with the chicken green-sensitive cone visual pigment, although it also has a relatively high homology with rhodopsins. These results give additional strength to the transmutation theory of Walls [Walls, G. L. (1934) Am. J. Ophthalmol. 17, 892-915], who proposed that the rod-shaped photoreceptor cells of lizards have been derived from ancestral cone-like photoreceptors. Apparently amino acid sequences of visual pigments are less changeable than the morphology of the photoreceptor cells in the course of evolution.
KW - Rod and cone
KW - Transmutation theory
KW - cDNA cloning
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U2 - 10.1073/pnas.89.15.6841
DO - 10.1073/pnas.89.15.6841
M3 - Article
C2 - 1379723
AN - SCOPUS:0026683469
SN - 0027-8424
VL - 89
SP - 6841
EP - 6845
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 15
ER -