Karyn Esser, Ph.D.

Karyn Esser, PhD
Karyn Esser, PhD


Associate Program Director, Institute of Myology

Phone: (352) 273-5728
Office: M544
Email: kaesser@ufl.edu

Education and Training/Previous Appointments

  • Postdoctoral Training: Children’s Medical Research Institute, Sydney, Australia (Muscle Genetics)
  • Ph.D.: The University of Michigan, Ann Arbor, MI (Kinesiology)
  • M.Ed.: University of Nevada Las Vegas, Las Vegas, NV (Physical Education)
  • B.S.: Wake Forest University,  Winston-Salem, NC (Math-Biology)

Research Interests

Skeletal muscle is the largest organ system in the body and is well known to be important for human health through its contribution to breathing and mobility and through its metabolic role as the primary site of sugar storage and fat metabolism.  Recent studies, however, have provided evidence that maintaining healthy muscle can increase longevity and can improve outcomes in chronic diseases such as cancer.

My lab has pioneered research on the role of circadian rhythms and the molecular clock mechanism in skeletal muscle homeostasis and health.  Using genetic mouse models, we found that mutations of two different molecular clock genes, Clock and Bmal1, dramatically disrupt skeletal muscle structure and function.  Parallel with our work on the molecular clock in skeletal muscle we are also pursuing the role of physical activity/exercise as a time cue for skeletal muscle and other tissues.  We have also shown that time of exercise can significantly alter the clock mechanism in skeletal muscle independent of lighting and the central clock in the brain. Our research goals are to define the transcriptional networks and downstream mechanisms that link the molecular clock with proper skeletal muscle function and phenotype.  Additionally we are working in mouse and human models to determine the potential for time of day lifestyle interventions as a therapeutic approach to enhance molecular clock function and attenuate conditions of muscle weakness and wasting seen with aging and chronic diseases.

Article: “Muscle Clocks Play a Role in Regulating Metabolism” by Diana Kwon (Contains an Interview with Dr. Esser)

Sites Related to Our Research 

Myology Institute Video

Teaching (Including Courses)

  • Human Physiology in Translation (BMS 3521)
  • Physiology Grant Writing (GMS5905)
  • Fundamentals of Physiology and Functional Genomics 3 (GMS 6473)
  • Seminar in Physiology (GMS 6495)

Awards and Honors

  • 2021: Awarded an R01 (R01AR079220) entitled “Circadian Clock and Muscle Health.”
  • 2021: Awarded an R01 (R01HL153042) entitled “Circadian clock regulation of myocardial ion channel expression and function.”
European Muscle Conference- 2018; August 30-September 3, Budapest, Hungary
  • Lance Riley: Young Investigator Award, Talk on “The Muscle Clock Regulates Titin Splicing and Sarcomere Length”.


PubMed Listing

    • Hodge, B. A., Zhang, X., Gutierrez-Monreal, M. A., Cao, Y., Hammers, D. W., Yao, Z., Wolff, C. A., Du, P., Kemler, D., Judge, A. R. … Esser, K. A. (2019). MYOD1 functions as a clock amplifier as well as a critical co-factor for downstream circadian gene expression in muscle. eLife, 8, e43017.  doi: 10.7554/eLife.43017. (PMID: 30789342)
    • Terry, E. E., Zhang, X., Hoffmann, C., Hughes, L. D., Lewis, S. A., Li, J., Wallace, M. J., Riley, L. A., Douglas, C. M., Gutierrez-Monreal, M. A., Lahens, N. F., Gong, M. C., Andrade, F., Esser, K. A., … Hughes, M. E. (2018). Transcriptional profiling reveals extraordinary diversity among skeletal muscle tissues. eLife7, e34613. doi:10.7554/eLife.34613. (PMID: 29809149; PMCID: PMC6008051)
    • Ehlen, J. C., Brager, A. J., Baggs, J., Pinckney, L., Gray, C. L., DeBruyne, J. P., Esser, K. A., Takahashi, J. S., … Paul, K. N. (2017). Bmal1 function in skeletal muscle regulates sleep. eLife6, e26557. doi:10.7554/eLife.26557. (PMID: 28726633; PMCID: PMC5574702)
  • Riley, L. A., & Esser, K. A. (2017). The Role of the Molecular Clock in Skeletal Muscle and What It Is Teaching Us About Muscle-Bone Crosstalk. Current osteoporosis reports15(3), 222-230. (PMID: 28421465; PMCID: PMC5442191)
  • Harfmann, B. D., Schroder, E. A., Kachman, M. T., Hodge, B. A., Zhang, X., & Esser, K. A. (2016). Muscle-specific loss of Bmal1 leads to disrupted tissue glucose metabolism and systemic glucose homeostasis. Skeletal muscle6, 12. doi:10.1186/s13395-016-0082-x. (PMID: 27486508; PMCID: PMC4969979)
  • Schroder, E. A., Harfmann, B. D., Zhang, X., Srikuea, R., England, J. H., Hodge, B. A., Wen, Y., Riley, L. A., Yu, Q., Christie, A., Smith, J. D., Seward, T., Wolf Horrell, E. M., Mula, J., Peterson, C. A., Butterfield, T. A., … Esser, K. A. (2015). Intrinsic muscle clock is necessary for musculoskeletal health. The Journal of physiology593(24), 5387-404. (PMID: 26486627; PMCID: PMC4704520)
  • Hodge, B. A., Wen, Y., Riley, L. A., Zhang, X., England, J. H., Harfmann, B. D., Schroder, E. A., … Esser, K. A. (2015). The endogenous molecular clock orchestrates the temporal separation of substrate metabolism in skeletal muscle. Skeletal muscle5, 17. doi:10.1186/s13395-015-0039-5. (PMID: 26000164; PMCID: PMC4440511)
  • Schroder, E. A., Burgess, D. E., Zhang, X., Lefta, M., Smith, J. L., Patwardhan, A., Bartos, D. C., Elayi, C. S., Esser, K. A., … Delisle, B. P. (2015). The cardiomyocyte molecular clock regulates the circadian expression of Kcnh2 and contributes to ventricular repolarization. Heart rhythm12(6), 1306-14. (PMID: 25701773; PMCID: PMC4541807)
  • Harfmann, B. D., Schroder, E. A., & Esser, K. A. (2014). Circadian rhythms, the molecular clock, and skeletal muscle. Journal of biological rhythms30(2), 84-94. (PMID: 25512305; PMCID: PMC4470613)
  • Schroder, E. A., & Esser, K. A. (2013). Circadian rhythms, skeletal muscle molecular clocks, and exercise. Exercise and sport sciences reviews41(4), 224-9. (PMID: 23917214; PMCID: PMC3866019)