The eyespot of Chlamydomonas reinhardtii: a comparative microspectrophotometric study.
The eyespot of Chlamydomonas reinhardtii is believed to utilize a rhodopsin-like pigment in its responses to light. This paper examines its eyespot by means of microspectrophotometry with the finding of an absorption spectrum with two bands, an A-band in the blue, and a B-band in the green. This spectrum is identical to that previously recorded from the eyespot of Euglena gracilis. As with Euglena the B-band was found to have dichroic character and its spectrum was similar to the absorption curve of rhodopsin. This A-B-spectrum was always recorded from a single granule in each cell. It is concluded that both E. gracilis and C. reinhardtii may utilize a rhodopsin-like pigment as the photopigment associated with the eyespot response to light. In both these algae a few particles in each cell were found whose spectra consisted of two other bands, C and D, blue- and red-shifted, respectively, relative to the eyespot A-B-bands. There is some reason to believe that the C-D-granules may also be involved in certain light-controlled activities of the cells.
Crescitelli
F
F
Department of Biology, University of California, Los Angeles 90024-1606.
James
T W
TW
Erickson
J M
JM
Loew
E R
ER
McFarland
W N
WN
D000818:Animals; D016825:Chlamydomonas reinhardtii / Q000737:chemistry*; D005056:Euglena gracilis / Q000737:chemistry; D005123:Eye / Q000737:chemistry*; D015591:Microspectrophotometry; D012243:Rhodopsin / Q000032:analysis
D012243:Rhodopsin