The Impact of the Co-Expression of Wnt1 and WLS on Filopodia Formation in 3T3 Cells
By: Megan Voss
Department: Biology
Faculty Advisors: Dr. Kai (Laura) Burrus, Dr. Lisa Galli
Humans function effectively with each other through communication, whether verbal or through pheromones to communicate implicit behaviors. Likewise, cells communicate by sending chemical signals from the “talking” cell to the “listening” cell. Cell communication is regulated by signaling molecules like Wnt (Wingless-related integration site) and WLS (Wntless), critical proteins in the Wnt signaling pathway. Wnt proteins are crucial in embryonic development and tissue homeostasis. Dysregulation of the Wnt pathway has been shown to cause embryonic defects, cancer, and neurological diseases. WLS is an essential integral membrane protein that binds to Wnt allowing for intracellular transport of Wnt to the cell membrane and filopodium. Inducing the Wnt signaling pathway in target cells requires Wnt transportation from Wnt producing to Wnt receiving cells. Filopodia are critical for this intercellular transport. We have previously determined that overexpression of WNT1 and WLS in chick neural crest cells and HEK293T cells induces filopodia. However, neither of those cell types is a good model system for studying filopodia induction. I hypothesize that the co-expression of WNT1 and WLS will induce new filopodia in 3T3 cells, which would be an excellent model system for further studies. To test my hypothesis, I have successfully co-expressed WNT1-GFP and WLS-mCherry in 3T3 cells, which have been confirmed through immunofluorescence assay. Using confocal microscopy, I will perform image analysis on transfected cells to quantify the length and number of filopodia. I expect the WNT1-GFP and WLS-mCherry expressing 3T3 cells will induce filopodia; compared to the WNT1 and WLS non-expressing control 3T3 cells. If successful, I will have established a new model system for studying the induction of filopodia by WNT1 and WLS.