[Formation of the photosensing system function in early development].
The function of simple prototypic eyes in two planarian species, the two ocular Girardia tigrina and the multiocular Polycelis tenuis, has been studied. When exposed to light, planarians display the light avoidance reaction known as negative phototaxis. This reaction has been investigated in intact animals and in head and tail fragments after their section in the course of eye regeneration. Specific features of the phototaxis reaction have been described in all groups of animals. The differences in light response recovery were shown between two planarian species and two regenerating fragments. No correlation between phototaxic reactions and the restoration of the eye structure, the number of eyes, the maturation of ganglion, the growth of regenerative blastema, and motor system has been found. The phototaxic response occurred two days after the recovery of the morphology of eyes and their connection with the brain. The participation of conserved and novel genes in early development of the eye function is discussed.
Sheĭman
I M
IM
Kreshchenko
N D
ND
Netreba
M V
MV
D000818:Animals; D005123:Eye / Q000254:growth & development; D017956:Photoreceptor Cells, Invertebrate / Q000502:physiology*; D010932:Planarians / Q000254:growth & development / Q000502:physiology*; D012038:Regeneration