The Star-Nosed Mole Reveals Clues to the Molecular Basis of Mammalian Touch

Kristin A. Gerhold, Maurizio Pellegrino, Makoto Tsunozaki, Takeshi Morita, Duncan B. Leitch, Pamela R. Tsuruda, Rachel B. Brem, Kenneth C. Catania, Diana M. Bautista

Little is known about the molecular mechanisms underlying mammalian touch transduction. To identify novel candidate transducers, we examined the molecular and cellular basis of touch in one of the most sensitive tactile organs in the animal kingdom, the star of the star-nosed mole. Our findings demonstrate that the trigeminal ganglia innervating the star are enriched in tactile-sensitive neurons, resulting in a higher proportion of light touch fibers and lower proportion of nociceptors compared to the dorsal root ganglia innervating the rest of the body. We exploit this difference using transcriptome analysis of the star-nosed mole sensory ganglia to identify novel candidate mammalian touch and pain transducers. The most enriched candidates are also expressed in mouse somatosesensory ganglia, suggesting they may mediate transduction in diverse species and are not unique to moles. These findings highlight the utility of examining diverse and specialized species to address fundamental questions in mammalian biology.