Mechanosensation -the transformation of mechanical stimuli into electrochemical signals-is ubiquitous in animals; it includes the senses of hearing, balance, touch, proprioception, as well as cellular functions such as volume regulation. The molecular basis of mechanosensitivity has been hard to discern because mechanosensitive organs are small and their constituent proteins are scarce. Recent genetic studies in the nematode Caenorhabditis elegans have revealed a dozen candidate proteins for mediating the sense of touch, in the process defining a new superfamily of ion channel proteins. A report in this issue now describes two interacting genes (
unc-105 and
let-2) expressed by C. elegans muscle that may be involved in the muscle's response to stretch;
unc-105 is a new member of this channel superfamily and
let-2 encodes a collagen.