Poster abstracts
Poster number 133 submitted by Emma Winland
Investigating the Role of ADARs and RNAi in the C. elegans Behavioral Immune Response
Emma Winland (Biochemistry Graduate Program, Indiana University), Alfa Dhakal (Cell, Molecular and Cancer Biology Graduate Program, Indiana University School of Medicine - Bloomington), Heather A. Hundley (Department of Biology, Indiana University)
Abstract:
All organisms continuously encounter environmental threats that require behavioral adaptation to survive. The nematode Caenorhabditis elegans provides a genetically tractable model for investigating these responses, as it naturally encounters many different bacteria as a food source. Once a pathogen is detected by C. elegans, not only are conserved immune signaling pathways activated, but the animal also mounts a behavioral response to avoid the pathogen. This avoidance response is critical for limiting pathogen exposure and promoting survival; however, the molecular mechanisms that regulate behavioral responses to pathogens remain unknown.
Behavioral responses to environmental threats require coordinated changes in gene expression. RNA-binding proteins (RBPs) regulate gene expression through diverse mechanisms, including changes in RNA modification/editing, stability, processing, localization, or translation. Among these RBPs, adenosine deaminases acting on RNA (ADARs) regulate RNA through binding and adenosine-to-inosine (A-to-I) editing, while the RNA interference (RNAi) pathway mediates sequence-specific gene silencing. Recent studies from our lab demonstrate that loss of ADARs in combination with RDE-4, an RNAi factor, increases the avoidance response of C. elegans to the opportunistic human pathogen Pseudomonas aeruginosa, which ultimately leads to increased survival. These findings suggest ADARs and RNAi interact to regulate the behavioral immune response to pathogens. We examined the specific roles of each of these RBPs by assaying the avoidance and survival of animals with mutations disrupting ADAR function and different RNAi factors. Future studies will use RNA sequencing to identify transcripts regulated by these pathways and determine how their targets contribute to pathogen avoidance and survival. This will provide insight into how two distinct RNA regulatory pathways coordinate to contribute to the behavioral immune response, revealing how RNA regulation influences an organism’s ability to adapt to environmental threats and survive pathogen exposure.
Keywords: RNA-binding proteins, RNA regulation, behavioral immunity