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Full-Text Articles in Neuroscience and Neurobiology
Animal Cryptochromes Mediate Magnetoreception By An Unconventional Photochemical Mechanism, Robert Gegear, Lauren Foley, Amy Casselman, Steven Reppert
Animal Cryptochromes Mediate Magnetoreception By An Unconventional Photochemical Mechanism, Robert Gegear, Lauren Foley, Amy Casselman, Steven Reppert
Robert J. Gegear
Understanding the biophysical basis of animal magnetoreception has been one of the greatest challenges in sensory biology. Recently it was discovered that the light-dependent magnetic sense of Drosophila melanogaster is mediated by the ultraviolet (UV)-A/blue light photoreceptor cryptochrome (Cry). Here we show, using a transgenic approach, that the photoreceptive, Drosophila-like type 1 Cry and the transcriptionally repressive, vertebrate-like type 2 Cry of the monarch butterfly (Danaus plexippus) can both function in the magnetoreception system of Drosophila and require UV-A/blue light (wavelength below 420 nm) to do so. The lack of magnetic responses for both Cry types at wavelengths above 420 …
Antennal Circadian Clocks Coordinate Sun Compass Orientation In Migratory Monarch Butterflies, Christine Merlin, Robert Gegear, Steven Reppert
Antennal Circadian Clocks Coordinate Sun Compass Orientation In Migratory Monarch Butterflies, Christine Merlin, Robert Gegear, Steven Reppert
Robert J. Gegear
During their fall migration, Eastern North American monarch butterflies (Danaus plexippus) use a time-compensated Sun compass to aid navigation to their overwintering grounds in central Mexico. It has been assumed that the circadian clock that provides time compensation resides in the brain, although this assumption has never been examined directly. Here, we show that the antennae are necessary for proper time-compensated Sun compass orientation in migratory monarch butterflies, that antennal clocks exist in monarchs, and that they likely provide the primary timing mechanism for Sun compass orientation. These unexpected findings pose a novel function for the antennae and open a …