Merlin, Christine individual record
Associate Professor

Our research broadly lies in understanding how organisms respond and adapt to changing environments, with an emphasis on circadian biology. Organisms from bacteria to humans use circadian clocks to control a plethora of biochemical, physiological and behavioral rhythms. These clocks are synchronized to daily and seasonal environmental changes to allow organisms to tune specific activities at the appropriate times of day or year.

In our laboratory, we use the eastern North American migratory monarch butterfly (Danaus plexippus) as a model system to study animal clock mechanisms and the role of circadian clocks and clock genes in a fascinating biological output, the animal long-distance migration. Every fall, like clockwork, millions of monarch butterflies start migrating thousands of miles from North America to reach their overwintering sites in central Mexico. During their journey south, migrating monarchs use a time-compensated sun compass orientation mechanism to maintain a constant flight bearing. Circadian clocks located in the antennae provide the critical internal timing device for compensation of the sun movement across the sky over the course of the day. The recent sequencing of the monarch genome and the establishment of genetic tools to knockout clock genes (and others) in vivo using nuclease-mediated gene targeting approaches provides us with a unique opportunity to uncover the molecular and cellular underpinnings of the butterfly clockwork, its migratory behavior and their interplay.

education and training
selected publications
Academic Articles25
  • Rivas, G., Zhou, J., Merlin, C., & Hardin, P. E. (2021). CLOCKWORK ORANGE promotes CLOCK-CYCLE activation via the putative Drosophila ortholog of CLOCK INTERACTING PROTEIN CIRCADIAN. Current Biology. 31(19), 4207-4218.e4.
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  • Wan, G., Hayden, A. N., Iiams, S. E., & Merlin, C. (2021). Cryptochrome 1 mediates light-dependent inclination magnetosensing in monarch butterflies.. Nat Commun. 12(1), 771.
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  • Nguyen, T., Beetz, M. J., Merlin, C., & El Jundi, B. (2021). Sun compass neurons are tuned to migratory orientation in monarch butterflies.. Proc Biol Sci. 288(1945), 20202988-20202988.
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  • Merlin, C., Iiams, S. E., & Lugena, A. B. (2020). Monarch Butterfly Migration Moving into the Genetic Era.. Trends Genet. 36(9), 689-701.
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  • Iiams, S. E., Lugena, A. B., Zhang, Y., Hayden, A. N., & Merlin, C. (2019). Photoperiodic and clock regulation of the vitamin A pathway in the brain mediates seasonal responsiveness in the monarch butterfly.. Proc Natl Acad Sci U S A. 116(50), 25214-25221.
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  • Reppert, S. M., Guerra, P. A., & Merlin, C. (2016). Neurobiology of Monarch Butterfly Migration.. Annual Reviews.
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  • Merlin, C., & Reppert, S. M. (2009). Molecular Biology and Genetics of the Lepidoptera. Goldsmith, M. R., & Marec, F. (Eds.), Molecular Biology and Genetics of the Lepidoptera. 137-152. CRC Press.
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mailing address
Texas A&M University; Biology; 3258 TAMU
College Station, TX 77843-3258