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Mechanosensitive cells are essential for organisms to sense the external and internal environments,and a variety of molecules have been implicated as mechanical sensors.We previously discovered that some olfactory sensory neurons(OSNs)in the mammalian nose responded to mechanical stimulation,a feature that drives the synchronization of olfactory bulb activity with the breathing cycle.Here we report that odorant receptors(ORs)-a large family of G-protein coupled receptors – underlie the responses to both chemical and mechanical stimuli in these neurons.Using patch clamp recordings of OSNs from genetically modified mice,we found that disruption of the olfactory signal transduction cascade completely eliminates mechanical responses in OSNs.Furthermore,OSNs expressing different receptor types display differential responses to mechanical stimuli.For instance,OSNs expressing the receptor I7,M71,or SR1 have much stronger mechanical responses than those expressing MOR23 and mOR-EG.Loss-of-function mutation of the I7 receptor,genetic switch of the M71 receptor,or ablation of the SR1 receptor,abolishes or dramatically reduces mechanical responses in the host OSNs.Finally,heterologous expression of SR1 but not mOR-EG confers mechanosensitivity to its host cells.These results suggest that ORs may serve as polymodal sensors of both chemical and mechanical stimuli,revealing a novel mechanism for mechanotransduction.