Biosciences Graduate Program

Wayne A. Johnson, PhD


Professor of Molecular Physiology and Biophysics

Contact Information

Primary Office:  
Phone: 319-335-7876

Office: 6-472  BSB
51 Newton Road
Iowa City, IA 52242

Lab: 6-473, 6-566  BSB
51 Newton Road
Iowa City, IA 52242



BS, Pharmacy, University of Wyoming
PhD, Pharmacology, University of Washington

Fellowship, Molecular and Cellular Biology, University of Washington
Fellowship, Biological Chemistry and Molecular Pharmacology, Harvard Medical School

Licensure and Certifications

Registered Pharmacist, Washington State Board of Pharmacy

Education/Training Program Affiliations

Department of Molecular Physiology and Biophysics PhD
Interdisciplinary Graduate Program in Genetics
Interdisciplinary Graduate Program in Neuroscience

Research Summary

Genetic analysis of locomotion behavior: molecular mechanisms of sensory signal transduction. Coordination of rhythmic locomotion such as crawling, swimming or walking depends upon a precisely balanced interplay between central and peripheral control mechanisms. Disruptions of this relationship caused by stroke, athletic injuries, peripheral neuropathy or osteoarthiritis can result in severe defects in motor control. Although significant advances have been made recently, we still have a relatively poor molecular understanding of how peripheral proprioceptive mechanosensory input is able to provide information about body position for moment to moment modifications of central mechanisms mediating rhythmic motor output. Does mechanosensory signaling in proprioceptive neurons designed to detect stretch or tension require a different signaling complex than neurons functioning in external touch sensation? We have developed a genetic model system in Drosophila to examine the molecular components of proprioceptive mechanosensation in type II multiple dendritic(md) sensory neurons. We have isolated a series of locomotion mutants displaying an unusual enhanced locomotion phenotype indicative of altered motor control. These mutant larvae crawl faster and farther with fewer stops and turns than wild-type larvae. One mutant gene encodes a Drosophila epithelial sodium channel subunit, Pickpocket1, making it a candidate mechanotransduction channel. We are currently utilizing the genomic and genetic resources available in the Drosophila system to clone other enhanced locomotion genes in our collection. Combined with an electrophysiological analysis of multiple dendritic neuron function, this molecular information should allow a more detailed characterization of their physiological functions and their relationships to each other.

Selected Publications

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Kim M, Johnson W.  Larval response to UVC irradiation is mediated by activation of larval nociceptors by reactive oxygen species .  BMC Neuroscience.  2014 January 16. 15(14).

Kim M, Ainsley J, Carder J, Johnson W.  Hyperoxia-triggered aversion behavior in Drosophila foraging larvae is mediated by sensory detection of hydrogen peroxide .  J. Neurogenetics.  2013 December. 27(4):151-62.

Johnson W, Carder J.  An ROS-mediated developmental shift in sensory modality mediates Drosophila larval food exit.  2012. 

Johnson W, Kim M, Ainsley J, Carder J.  Drosophila H2O2-activated sensory neurons mediate larval behavioral response to external environmental changes.  2012. 

Johnson W, Carder J.  Drosophila nociceptors mediate larval aversion to dry surface environments utilizing both the Painless TRP channel and the DEG/ENaC subunit, PPK1.  2012. 7:e32878.

Johnson W, Kim M.  Larval response to UVC irradiation is mediated by activation of larval nociceptors by reactive oxygen species.  2012. 

Johnson W, Vermehren-Schmaedick A, Ainsley J, Davies S, Morton D.  Behavioral Responses to Hypoxia in Drosophila Larvae Are Mediated by Atypical Soluble Guanyl Cyclases.  2010. 186:183-196.

Johnson W, Wegman L, Ainsley J.  Developmental timing of a sensory-mediated larval surfacing behavior correlates with cessation of feeding and determination of final adult size.  2010. 345:170-179.

Johnson W, Ainsley J, Kim M, Wegman L, Pettus J.  Sensory mechanisms controlling the timing of larval developmental and behavioral transitions require the Drosophila DEG/ENaC subunit, Pickpocket1.  2008. 322:46-55.

Johnson W, Liu L, Leonard A, Motto D, Feller M, Price M, Welsh M.  Contribution of Drosophila DEG/ENaC genes to salt taste.  2003. 39:133-146.

Date Last Modified: 06/06/2016 - 13:17:48