Mechanosensory inputs influence Caenorhabditis elegans pharyngeal activity via ivermectin sensitivity genes.
Mechanical stimulation induces opposite behavioral responses in the adult and dauer pharynx. Tail tap of adults inhibits pharyngeal pumping via a pathway involving the innexin gene unc-7 and components of the glutamatergic pathway encoded by the genes avr-14 and avr-15. Tail tap of dauers stimulates pumping through a mechanism involving G alpha o and G alpha q. The nematocidal drug ivermectin is believed to kill worms by opening a glutamate-gated chloride channel (AVR-15) on pharyngeal muscle, causing complete pumping inhibition. However, ivermectin can also inhibit pumping in the absence of this channel. We propose that one of the ways ivermectin could prevent pumping, in the absence of the AVR-15 ivermectin-binding channel on pharynx muscle, is to target AVR-14 and AVR-15, which are expressed in the inhibitory pathway linking mechanosensation and pumping activity.
Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9148, USA. j.keane@sussex.ac.uk
John
J
Keane
Leon
L
Avery
D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism; D005247:Feeding Behavior; D044385:GTP-Binding Protein alpha Subunits; D005786:Gene Expression Regulation; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism; D007559:Ivermectin / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000378:metabolism; D010614:Pharynx / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology
D029742:Caenorhabditis elegans Proteins; D044385:GTP-Binding Protein alpha Subunits; D008565:Membrane Proteins; D018377:Neurotransmitter Agents; C094444:Unc-7 protein, C elegans; C084618:olfactory G protein subunit alpha olf; D007559:Ivermectin; D020962:Heterotrimeric GTP-Binding Proteins