Abstract
Temperature is a critical modulator of animal metabolism and behavior, yet the mechanisms underlying the development and function of thermosensory neurons are poorly understood.
C. elegans senses temperature using the AFD thermosensory neurons. Mutations in the gene
ttx-1 affect AFD neuron function. Here, we show that
ttx-1 regulates all differentiated characteristics of the AFD neurons.
ttx-1 mutants are defective in a thermotactic behavior and exhibit deregulated thermosensory inputs into a neuroendocrine signaling pathway.
ttx-1 encodes a member of the conserved OTD/OTX homeodomain protein family and is expressed in the AFD neurons. Misexpression of
ttx-1 converts other sensory neurons to an AFD-like fate. Our results extend a previously noted conservation of developmental mechanisms between the thermosensory circuit in
C. elegans and the vertebrate photosensory circuit, suggesting an evolutionary link between thermosensation and phototransduction.