Caenorhabditis elegans forages for food by distinguishing between various odorants in a dynamic environment. Their sensory neurons have the ability to adapt to persistent odors when the animal is starved (Bargmann, 2006). Adaptation to specific odors takes place in the AWC, a paired olfactory sensory neuron. In the AWC, a transmembrane guanylyl cyclase,
odr-1, is required for chemotaxis towards all odorants. Prolonged odor exposure results in decreased chemotaxis, which correlates with a decrease in
odr-1 mRNA. Odor adaptation is initiated by the translocation of a protein kinase, EGL-4, into the nucleus of the AWC (L'Etoile et al., 2002; Lee et al., 2010). Nuclear EGL-4 promotes a 22G directed repression of the
odr-1 gene thereby initiating long-term odor adaptation (Juang et al., submitted). ChIP indicated that the heterochromatin state at the
odr-1 locus increases during AWC odor adaptation and this increase requires 22G RNA synthesis. However, qRT-PCR and ChIP analysis does not offer a dynamic or cell-specific readout of
odr-1 22G RNA function. Here we describe our plans to create a fluorescent reporter that is capable of tracking changes in
odr-1 22G RNA function in live worms as they adapt to odor. The sensors that detect
odr-1 22G RNAs are inserted via Mos Single Copy Insertion (MosSCI). These sensors will have the capability to detect specific
odr-1 22G RNA function in the AWC olfactory sensory neuron as well as cells throughout the worm. The creation of a single copy insertion of an
odr-1 small RNA sensor will allow us to test our hypothesis that a small RNA-directed pathway is dynamically activated during olfactory adaptation. In addition, this tool will allow us to understand whether
odr-1 22G RNA represses transcription of our reporter in other cells in the worm.