title: Effect of pronase treatment on step-down and step-up photophobic responses in Euglena gracilis.
abstract: Pronase-treated cells of Euglena gracilis Z show no discernible ultrastructural effects on the photoreceptor apparatus; however, there are physiological effects on swimming speed and on step-up and step-down photophobic responses, especially the latter. Pronase acts differently on the two photophobic responses: the step-down response is completely inhibited after 2 hr., whereas inhibition of the step-up response occurs in only 50% of the cells even after 24 hr. The effects are fully reversible, with step-up recovery quite rapid and step-down recovery considerably slower.
mesh_terms: D000818:Animals; D005056:Euglena gracilis / Q000502:physiology* / Q000528:radiation effects / Q000648:ultrastructure; D008027:Light; D010786:Photoreceptor Cells / Q000502:physiology; D011402:Pronase
chemical_list: D011402:Pronase