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Full-Text Articles in Neuroscience and Neurobiology
Discordant Timing Between Antennae Disrupts Sun Compass Orientation In Migratory Monarch Butterflies, Patrick Guerra, Christine Merlin, Robert Gegear, Steven Reppert
Discordant Timing Between Antennae Disrupts Sun Compass Orientation In Migratory Monarch Butterflies, Patrick Guerra, Christine Merlin, Robert Gegear, Steven Reppert
Robert J. Gegear
To navigate during their long-distance migration, monarch butterflies (Danaus plexippus) use a time-compensated sun compass. The sun compass timing elements reside in light-entrained circadian clocks in the antennae. Here we show that either antenna is sufficient for proper time compensation. However, migrants with either antenna painted black (to block light entrainment) and the other painted clear (to permit light entrainment) display disoriented group flight. Remarkably, when the black-painted antenna is removed, re-flown migrants with a single, clear-painted antenna exhibit proper orientation behaviour. Molecular correlates of clock function reveal that period and timeless expression is highly rhythmic in brains and clear-painted …
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 …