I will study opsins, the visual pigments
that mediate vision, to shed light into the evolutionary relationship between male colour and female preferences.
TEHRAN (FNA)- Many genetic mutations in visual pigments
, spread over millions of years, were required for humans to evolve from a primitive mammal with a dim, shadowy view of the world into a greater ape able to see all the colors in a rainbow.
and colour vision in a nocturnal bird, Strix aluco (Tawny Owl).
Most mammals have two spectral cone types containing either of two visual pigments
(opsins), one sensitive to shortwave light (UV/blue opsin), and the other to middle-to-longwave light (green opsin).
Jeremy Nathans determined the genetic code of the human visual pigments
, helping to understand how they function and discovering how mutations in their sequence can lead to some retinal diseases.
The RPE cells perform several functions, including absorption of light, enabling the turnover of photoreceptor outer segments, formation of visual pigments
by storing and releasing vitamin A.
clathratus are known to also be active at night, and their scotopic visual pigments
are well adapted to low-light conditions (Hobson et al.
Sequence analysis of the deduced 362 amino acid protein indicates that it belongs firmly in the SWS2 class of visual pigments
and has high amino acid sequence identity with bullfrog SWS2 pigment.
Whereas we humans have four visual pigments
in our eyes, they have 16.
For their study, Hart and his team used a different technique - microspectrophotometry - to identify cone visual pigments
in shark retinas and measure their spectral absorbance.
An expert in visual pigments
, Szuts believes the rhodopsin from the shrimp offers an important clue that cannot be overlooked.
Cones rely on light-sensing molecules that bind together to make up visual pigments