An explosion of information has occurred over the past few years in the field of signal transduction. As information form prokaryotes and eukaryotes has accumulated, it has become evident that diverse sensory systems share common mechanistic themes. This volume reviews our the current knowledge of molecular mechanisms for sensory transduction in a variety of microbial systems, as well as elegant work done in nematodes and Drosophila. Signal Transduction is intended for both researchers studying microbial systems and investigators and students of signal transduction in more complex organisms, who can learn from the paradigms and mechanisms conserved between prokaryotes and eukaryotes.