Mechanosensitive Ion Channels in Caenorhabditis elegans

Caenorhabditis elegans depends critically on mechanosensory perception to negotiate its natural habitat, the soil. The worm displays a rich repertoire of mechanosensitive behaviors, which can be easily examined in the laboratory. This, coupled with the availability of sophisticated genetic and molecular biology tools, renders C. elegans a particularly attractive model organism to study the transduction of mechanical stimuli to biological responses. Systematic genetic analysis has facilitated the dissection of the molecular mechanisms that underlie mechanosensation in the nematode. Studies of various worm mechanosensitive behaviors have converged to identify highly specialized plasma membrane ion channels that are required for the conversion of mechanical energy to cellular signals. Strikingly, similar mechanosensitive ion channels appear to function at the core of the mechanotransduction apparatus in higher organisms, including humans. Thus, the mechanisms responsible for the detection of mechanical stimuli are likely conserved across metazoans. The nematode offers a powerful platform for elucidating the fundamental principles that govern the function of metazoan mechanotransducers. This chapter evaluates the current understanding of mechanotransduction in C. elegans and focuses on the role of mechanosensitive ion channels in specific mechanosensory behavioral responses. The chapter also outlines potential unifying themes, common to mechanosensory transduction in diverse species.