Joined the Department in 2013
- B.S., 2002, Animal Biology, University Paris 6 Pierre and Marie Curie, France.
- M.S., 2003, Invertebrate Physiology, University Paris 6 Pierre and Marie Curie, France.
- Ph.D., 2006, Insect Physiology, University Paris 6 Pierre and Marie Curie, France.
- Postdoctoral research, Molecular Neuroethology, University of Massachusetts Medical School, USA.
Center for Biological Clocks Research
Faculty of Genetics
Texas A&M Institute for Neuroscience
Circadian clocks in the migration of the monarch butterfly: from genes to behavior
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.
We are using integrative approaches that include molecular, genetic, genome-wide profiling approaches, and behavior to more specifically address: 1) how the circadian clock and clock genes govern the photoperiodic seasonal migratory switch and 2) the molecular and genetic bases underlying the migratory behavior. We also continue to develop innovative gene-targeting approaches (using TALENs) to knock-in reporter tags into clock genes loci to gain insights into the clock circuitry involved in both seasonal responses and navigation.
- Nguyen, TAT, Beetz, MJ, Merlin, C, El Jundi, B. Sun compass neurons are tuned to migratory orientation in monarch butterflies. Proc Biol Sci. 2021;288 (1945):20202988. doi: 10.1098/rspb.2020.2988. PubMed PMID:33622121 PubMed Central PMC7935079.
- Wan, G, Hayden, AN, Iiams, SE, Merlin, C. Cryptochrome 1 mediates light-dependent inclination magnetosensing in monarch butterflies. Nat Commun. 2021;12 (1):771. doi: 10.1038/s41467-021-21002-z. PubMed PMID:33536422 PubMed Central PMC7859408.
- Merlin, C, Iiams, SE, Lugena, AB. Monarch Butterfly Migration Moving into the Genetic Era. Trends Genet. 2020;36 (9):689-701. doi: 10.1016/j.tig.2020.06.011. PubMed PMID:32713598 .
- Iiams, SE, Lugena, AB, Zhang, Y, Hayden, AN, Merlin, C. 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. 2019;116 (50):25214-25221. doi: 10.1073/pnas.1913915116. PubMed PMID:31767753 PubMed Central PMC6911188.
- Lugena, AB, Zhang, Y, Menet, JS, Merlin, C. Genome-wide discovery of the daily transcriptome, DNA regulatory elements and transcription factor occupancy in the monarch butterfly brain. PLoS Genet. 2019;15 (7):e1008265. doi: 10.1371/journal.pgen.1008265. PubMed PMID:31335862 PubMed Central PMC6677324.
- Merlin, C, Liedvogel, M. The genetics and epigenetics of animal migration and orientation: birds, butterflies and beyond. J Exp Biol. 2019;222 (Pt Suppl 1):. doi: 10.1242/jeb.191890. PubMed PMID:30728238 .
- Denlinger, DL, Hahn, DA, Merlin, C, Holzapfel, CM, Bradshaw, WE. Keeping time without a spine: what can the insect clock teach us about seasonal adaptation?. Philos Trans R Soc Lond B Biol Sci. 2017;372 (1734):. doi: 10.1098/rstb.2016.0257. PubMed PMID:28993500 PubMed Central PMC5647283.
- Zhang, Y, Markert, MJ, Groves, SC, Hardin, PE, Merlin, C. Vertebrate-like CRYPTOCHROME 2 from monarch regulates circadian transcription via independent repression of CLOCK and BMAL1 activity. Proc Natl Acad Sci U S A. 2017;114 (36):E7516-E7525. doi: 10.1073/pnas.1702014114. PubMed PMID:28831003 PubMed Central PMC5594645.
- Markert, MJ, Zhang, Y, Enuameh, MS, Reppert, SM, Wolfe, SA, Merlin, C et al.. Genomic Access to Monarch Migration Using TALEN and CRISPR/Cas9-Mediated Targeted Mutagenesis. G3 (Bethesda). 2016;6 (4):905-15. doi: 10.1534/g3.116.027029. PubMed PMID:26837953 PubMed Central PMC4825660.
- Reppert, SM, Guerra, PA, Merlin, C. Neurobiology of Monarch Butterfly Migration. Annu Rev Entomol. 2016;61 :25-42. doi: 10.1146/annurev-ento-010814-020855. PubMed PMID:26473314 .