Joined: Feb. 2006
|Quote (Wesley R. Elsberry @ Jan. 21 2009,16:38)|
Light-sensitive neurons and channels mediate phototaxis in C. elegans.
Ward A, Liu J, Feng Z, Xu XZ.
Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, Michigan 48109, USA.
Phototaxis behavior is commonly observed in animals with light-sensing organs. C. elegans, however, is generally believed to lack phototaxis, as this animal lives in darkness (soil) and does not possess eyes. Here, we found that light stimuli elicited negative phototaxis in C. elegans and that this behavior is important for survival. We identified a group of ciliary sensory neurons as candidate photoreceptor cells for mediating phototaxis. Furthermore, we found that light excited photoreceptor cells by evoking a depolarizing conductance carried by cyclic guanosine monophosphate (cGMP)-sensitive cyclic nucleotide-gated (CNG) channels, revealing a conservation in phototransduction between worms and vertebrates. These results identify a new sensory modality in C. elegans and suggest that animals living in dark environments without light-sensing organs may not be presumed to be light insensitive. We propose that urbilaterians, the last common ancestor of bilaterians, might have already evolved a visual system that employs CNG channels and the second messenger cGMP for phototransduction.
Light sensitivity without eyes... how about that.
Wes, I have no problem with that. Even a no-see-em has an
optic nerve between the eye and brain. I read somewhere that
some butterflies have tastebuds in their feet.
Even earthworms and blind people know when they are in
Psa 22:6 But I [am] a worm, and no man; a reproach of men,
and despised of the people.
Lou, I agree. IMO, always give credit where credit is due.
Higgins was the only point I was making however.
And thanks to both of you for talking to me.
360 miracles and more at:
Great news. God’s wife is pregnant! (Rev. 12:5)
It's not over till the fat lady sings! (Isa. 54:1 & Zec 9:9)