Efficient and cell specific knock-down of gene function in targeted C-elegans neurons

The nematode C elegans has become an important model for understanding how genes influence behavior. However, in this organism the available approaches for identifying the neuron(s) where the function of a gene is required for a given behavioral trait are time consuming and restricted to non essential genes for which mutants are available. We describe a simple reverse genetics approach for reducing, in chosen C elegans neurons, the function of genes. The method is based on the expression, under cell specific promoters, of sense and antisense RNA corresponding to a gene of interest. By targeting the genes osm-10, osm-6 and the Green Fluorescent Protein gene, gfp, we show that this approach leads to efficient, heritable and cell autonomous knock-downs of gene function, even in neurons usually refractory to classic RNA interference (RNAi). By targeting the essential and ubiquitously expressed gene, gpb-1, which encodes a G protein subunit, we identify for the first time two distinct sets of neurons in which the function of gpb-1 is required to regulate two distinct behaviors: egg-laying and avoidance of repellents. The cell specific knock-downs obtained with this approach provide information that is complementary to that provided by the cell specific rescue of loss-of- function mutations and represents a useful new tool for dissecting the role that genes play in selected neurons. (c) 2007 Elsevier B.V All rights reserved.