Dial "R" for RNAi : Silencing Stem Cell Proliferation in the C. elegans Germline

Andy Ho¹, Tim Schedl², Momoyo Matsuyama², Biology Department, Washington University, St. Louis, MO¹, Department of Genetics, Washington University School of Medicine²

RNAi (RNA Interference) is a technique for precisely knocking down or silencing gene activity following exposure of C. elegans worms to the homologous double stranded RNA (dsRNA). The method of RNAi performed in this project was feeding RNAi, where the worms are soaked in a lawn of specifically engineered E.coli in order to synthesize the dsRNA to the desired gene. This method works phenomenally well with C. elegans because they directly absorb the dsRNA through ingestion. Introduction of dsRNA into an adult worm results in the degradation of the targeted mRNA, thus leading to loss of function for both the adult and its progeny.

This project utilizes RNAi to identify genes that are negative regulators of the GLP-1/Notch signaling pathway. The GLP-1/Notch pathway promotes germ cell proliferation in C. elegans. When signaling is reduced, germ cells undergo meiotic development forming gametes. A sensitized background is used, glp-1(oz264), where loss of a negative regulator of GLP-1/Notch results in germline tumor formation. A feeding RNAi screen was performed for a number of genes, searching for a germline tumorous phenotype that results from loss of a negative regulator.