THE PHOTOSENSITIVE RETINAL PIGMENT SYSTEM OF XXXX .

@entity27914 @entity227 @entity11040 @entity969 @entity14786 @entity5995
Retinal extracts of @entity27914 were found to contain two @entity5995 (1) photopigments, one with maximum absorption at about 521 mmicro, the second with a maximum in the region of 478 mmicro. These pigments were assayed by the method of partial bleaching and their spectral characteristics studied by examining their difference spectra. The 478 mmicro pigment was present in the extracts as 8 per cent of the total photopigment concentration. The two pigment systems were shown to be biochemically independent and to have different properties. Unlike the 521 mmicro pigment, for example, the 478 mmicro pigment was found to resist the action of @entity14786 and, within the cells, to be unaffected by @entity969 solutions. These solutions destroyed or altered the 521 system so that extracts of @entity969 -treated retinae were found to contain significantly less 521 photopigment. In @entity11040 solution the 521 pigment was unaffected by @entity969 treatment. Both pigments were extracted from separated, washed outer segments and so are considered to be @entity227 . This dual system accounts for the spectral sensitivity of this gecko as determined by Denton. A search was made, but no evidence was secured for the presence of a photopigment absorbing at longer wavelengths. Electoretinographic data suggest, however, that an elevated sensitivity at longer wavelengths occurs in some geckos so that a continued search is justified for a third photopigment.
