The thermal sensitivity of TRPAs varies by species. For example, TRPA1 functions as a high-temperature sensor in insects and snakes, but as a cold sensor in mammals.[8] The basal TRPAs have evolved some degree of thermal sensitivity as well: painless and pyrexia function in high-temperature sensing in Drosophila melanogaster, and the honey bee HsTRPA underwent neofunctionalization following its divergence from waterwitch, gaining function as a high-temperature sensor.[9]
TRPA1s promiscuity with respect to sensory modality has been the source of controversy, particularly when considering its ability to detect cold.[10] More recent work has alternatively (or additionally) proposed that reactive oxygen species activate TRPA1, across species.[11][12]
