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Action Spectra for Step‐Up Photophobic Response in Blepharisma
Author(s) -
MATSUOKA TATSUOMI,
MATSUOKA SETSUKO,
YAMAOKA YUMIKO,
KURIU TOSHIHIKO,
WATANABE YOSHIYA,
TAKAYANAGI MIYUKI,
KATO YOJI,
TANEDA KOJI
Publication year - 1992
Publication title -
the journal of protozoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 0022-3921
DOI - 10.1111/j.1550-7408.1992.tb04838.x
Subject(s) - pigment , action spectrum , blue light , biophysics , absorption (acoustics) , red light , absorption spectroscopy , chemistry , photochemistry , biology , botany , optics , physics , organic chemistry
The cells of Blepharisma which possess red pigment (blepharismin) show step‐up photophobic response (temporal ciliary reversal induced by a sudden increase in light intensity). Bleaching of the cells by cold shock raised a threshold light intensity for the response, Oxidation of red pigment that produced blue pigment did not raise the threshold for the response. The action spectrum for the step‐up photophobic response of the cells which possess normal red pigment had peaks at about 580, 540 and 490 nm, a value which coincided with peaks of an absorption spectrum of the red pigment. The absorption spectrum of oxidized pigment (blue pigment) shifted 20 nm toward infrared light. The action spectrum for the response of the cells which possess blue pigment also shifted 20 nm toward infrared light. Results suggest that red pigment might be involved in the step‐up photophobic response. Key words. Blepharismin, ciliary reversal, photoreceptors, photoresponse.