FBS Colloquia No.352Laboratory for Single-cell Neurobiology

Neural circuits of temperature and oxygen that generate temperature response diversity.

Temperature is one of the most important environmental factors for organisms. To elucidate the mechanisms of temperature response in animals, we used natural variation strains of nematode C. elengans isolated from different parts of the world. Australian strains can quickly acclimate to new temperatures, while Hawaiian strains slowly acclimate to new temperatures (Okahata et al., JCPB, 2016). We identified the VH gene as the responsible polymorphism that determine temperature acclimation diversity by performing Next-generation sequencer analysis and SNP analysis. VH gene was expressed in oxygen sensory neuron. Previously reported that environmental oxygen information affects the thermos responsivity of ADL thermos-sensory neuron and modulate temperature acclimation (Okahata et al., Science Advances, 2019). We therefore hypothesized that oxygen information from oxygen sensory neuron might affect the temperature responsivity of ADL thermo-sensory neuron via the VH gene. VH mutants exhibited the decrement of thermo-responsivity of ADL, compared to the wild-type animals. The mutant defective in oxygen receptor also showed abnormal ADL thermos-responsivity. To investigate whether oxygen information generates temperature response diversity, we measured temperature acclimation of natural variation strains cultivated under different oxygen concentration. When animals were cultivated under high oxygen concentrations, Australian strains showed different temperature response to Hawaiian strains. In contrast, they did not show temperature response diversity under low oxygen concentrations. These results suggest that environmental oxygen information generates temperature response diversity.