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Professor of Molecular Physiology and Biophysics
Office: 6-472 BSB51 Newton RoadIowa City, IA 52242
Lab: 6-473, 6-566 BSB51 Newton RoadIowa City, IA 52242
BS, Pharmacy, University of WyomingPhD, Pharmacology, University of Washington
Fellowship, Molecular and Cellular Biology, University of WashingtonFellowship, Biological Chemistry and Molecular Pharmacology, Harvard Medical School
Registered Pharmacist, Washington State Board of Pharmacy
Biosciences Graduate ProgramDepartment of Molecular Physiology and Biophysics PhDInterdisciplinary Graduate Program in GeneticsInterdisciplinary Graduate Program in Neuroscience
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.
An ROS-mediated developmental shift in sensory modality mediates Drosophila larval food exit.
2012. Johnson W,
Drosophila H2O2-activated sensory neurons mediate larval behavioral response to external environmental changes.
2012. Johnson W,
Drosophila nociceptors mediate larval aversion to dry surface environments utilizing both the Painless TRP channel and the DEG/ENaC subunit, PPK1.
Larval response to UVC irradiation is mediated by activation of larval nociceptors by reactive oxygen species.
2012. Johnson W,
Behavioral Responses to Hypoxia in Drosophila Larvae Are Mediated by Atypical Soluble Guanyl Cyclases.
Developmental timing of a sensory-mediated larval surfacing behavior correlates with cessation of feeding and determination of final adult size.
Sensory mechanisms controlling the timing of larval developmental and behavioral transitions require the Drosophila DEG/ENaC subunit, Pickpocket1.
Contribution of Drosophila DEG/ENaC genes to salt taste.
Drosophila DEG/ENaC/pickpocket genes are expressed in the tracheal system where they may be involved in liquid clearance .
Function of the Drosophila POU-domain transcription factor Drifter as an upstream regulator of Breathless receptor tyrosine kinase expression in developing trachea.
Date Last Modified: 06/04/2015 -
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