A third, ultraviolet-sensitive, visual pigment in the Tokay gecko (Gekko gekko).
Vision Res
; 34(11): 1427-31, 1994 Jun.
Article
em En
| MEDLINE
| ID: mdl-8023453
ABSTRACT
Numerous extraction and microspectrophotometric studies have shown that the nocturnal Tokay gecko (Gekko gekko), has two visual pigments a "green" with lambda max at 521 nm and a "blue" at 467 nm. In addition, similar studies on other nocturnal gecko species have found only the same two classes of visual pigment. With the finding that some diurnal species of gecko have a third visual pigment class with lambda max peaking in the UV, doubts were raised concerning the presence of only two visual pigment classes in nocturnal forms. Therefore, a microspectrophotometric re-examination of the Tokay gecko was undertaken to look specifically for a UV visual pigment. A UV-absorbing pigment (364 nm lambda max) was found in approx. 20% of the thin outer segments of type C double rods, thought previously to contain only the 467 nm pigment. That this UV-absorbing pigment was truly a visual pigment was confirmed by its dichroism, behaviour following exposure to UV radiation and "nomogram" fit. It is suggested that this visual pigment had been seen in previous microspectrophotometric studies, but its similarity to known photoproducts peaking in the same spectral region resulted in a case of mistaken identity.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Retina
/
Lagartos
Tipo de estudo:
Diagnostic_studies
Limite:
Animals
Idioma:
En
Revista:
Vision Res
Ano de publicação:
1994
Tipo de documento:
Article