Every fall, millions of monarch butterflies embark on a remarkable journey, traveling thousands of miles from North America to central Mexico. But how do these delicate creatures navigate such vast distances with such precision? Dr. Christine Merlin, Professor in the Department of Biology and Presidential Impact Fellow, is unraveling the mysteries behind this fascinating migration.
At the Merlin Lab, housed within the Center for Biological Clocks Research, Merlin and their team use the monarch butterfly (Danaus plexippus) as a model system to study the biological clock mechanisms in living organisms. These mechanisms, or circadian clocks, coordinate a plethora of behaviors and physiological processes. In monarchs, they are essential for migration.
During their journey south, migrating monarchs use their circadian clocks and magnetic neural pathways located in their antennae to detect Earth’s magnetic field and help them navigate a consistent flight path. As days shorten in the fall, the monarchs enter a state of reproductive dormancy, known as diapause, which helps them conserve energy during migration and overwintering. In the spring, increasing daylight and warmer temperatures reverse this dormancy, prompting mating and a return journey northward to lay eggs on milkweed plants in southern Texas.
Yet the underlying mechanisms which drive the monarchs’ behavior remain unknown. Merlin and their team are currently pursuing this exciting research using integrative and cutting-edge molecular, genetic, and behavioral approaches. Recent advancements in genome sequencing and the Merlin Lab’s development of in vivo nuclease-mediated gene targeting are paving the way for new discoveries in circadian and monarch biology.
This research was funded in part by the National Institute of General Medical Sciences (5R01GM124617).