Audra Amasino with Dana Byrd and Judith Kimble

Department of Biochemistry, UW-Madison

We developed a way to look at gene function in a single cell within a live multicellular organism, the nematode C. elegans. We genetically engineered a strain of C. elegans in such a way that allowed us to knock out genes one by one in the Distal Tip Cell of the C. elegans gonad using RNAi. RNAi is a cellular process in which a cell attacks double stranded RNA and then prevents further mRNA of the same sequence from being translated. Scientists can insert double stranded RNA of any sequence into a cell and achieve this result.

We took a strain of C. elegans that lacked rde-1, a necessary gene for RNAi, and rescued rde-1 using Plag2, a promoter specific to the DTC. This created a worm in which the double stranded RNA of a specific gene (which is delivered by feeding to worms) would only prevent gene expression in the DTC. The DTC is a somatic cell that controls germline development and maintains mitotic germline stem cells. We have a list of genes expressed in the DTC obtained from microarray analysis.  The strain we created this summer provides a tool to analyze the effect of these genes on DTC function.