Motion vision is independent of color in Drosophila
- *Department of Genetics and Neurobiology, Biozentrum, University of Würzburg, 97074 Würzburg, Germany; and
- †Center for Developmental Genetics, New York University, New York, NY 10003
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Edited by John G. Hildebrand, University of Arizona, Tucson, AZ, and approved January 15, 2008 (received for review December 6, 2007)
Abstract
Whether motion vision uses color contrast is a controversial issue that has been investigated in several species, from insects to humans. We used Drosophila to answer this question, monitoring the optomotor response to moving color stimuli in WT and genetic variants. In the fly eye, a motion channel (outer photoreceptors R1–R6) and a color channel (inner photoreceptors R7 and R8) have been distinguished. With moving bars of alternating colors and high color contrast, a brightness ratio of the two colors can be found, at which the optomotor response is largely missing (point of equiluminance). Under these conditions, mutant flies lacking functional rhodopsin in R1–R6 cells do not respond at all. Furthermore, genetically eliminating the function of photoreceptors R7 and R8 neither alters the strength of the optomotor response nor shifts the point of equiluminance. We conclude that the color channel (R7/R8) does not contribute to motion detection as monitored by the optomotor response.
Footnotes
- ‡To whom correspondence should be addressed. E-mail: heisenberg{at}biozentrum.uni-wuerzburg.de
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Author contributions: S.Y., R.W., and M.H. designed research; S.Y. performed research; S.Y., R.W., and C.D. contributed new reagents/analytic tools; S.Y. and R.W. analyzed data; and S.Y., R.W., C.D., and M.H. wrote the paper.
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The authors declare no conflict of interest.
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This article is a PNAS Direct Submission.
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This article contains supporting information online at www.pnas.org/cgi/content/full/0711484105/DC1.
- © 2008 by The National Academy of Sciences of the USA
