Abstract
Migratory monarch butterflies (Danaus plexippus) use a time-compensated sun compass to navigate to their overwintering grounds in Mexico. Although polarized light is one of the celestial cues used for orientation, the spectral content (color) of that light has not been fully explored. We cloned the cDNAs of three visual pigment-encoding opsins (ultraviolet [UV], blue, and long wavelength) and found that all three are expressed uniformly in main retina. The photoreceptors of the polarization-specialized dorsal rim area, on the other hand, are monochromatic for the UV opsin. Behavioral studies support the importance of polarized UV light for flight orientation. Next, we used clock protein expression patterns to identify the location of a circadian clock in the dorsolateral protocerebrum of butterfly brain. To provide a link between the clock and the sun compass, we identified a CRYPTOCHROME-staining neural pathway that likely connects the circadian clock to polarized light input entering brain.
| Original language | English |
|---|---|
| Pages (from-to) | 457-467 |
| Number of pages | 11 |
| Journal | Neuron |
| Volume | 46 |
| Issue number | 3 |
| DOIs | |
| State | Published - 5 May 2005 |
Bibliographical note
Funding Information:We thank Choogon Lee for producing the monarch anti-CRY antibodies; David R. Weaver for suggestions; Aditi V. Chavda, Lawrence Lee, Kasia Macko, Marilou Sison-Mangus, and Guillermo Zaccardi for assistance; Steve A. Kay for reagents; Makio Takeda and Michael W. Young for antibodies; and Carol Cullar for supplying migratory butterflies. J.S. contributed to the opsin expression parts of the paper. This work was supported in part by NIH grant R01 NS047141 (S.M.R.); GAAVCR grant A5007205 (I.S.); NSF grant IBN-0346765 (A.D.B.); and a German Academy Exchange Service Grant (DAAD) and the Volkswagenstiftung to J.S.