Dual roles of Drosophila glypican Dally-like in Wingless/Wnt signaling and distribution. 
Heparan sulfate proteoglycans (HSPGs) are cell-surface and extracellular matrix (ECM) macromolecules that comprise a core protein to which heparan sulfate (HS) glycosaminoglycan (GAG) chains are attached.  Glypican is a major family of HSPGs that is linked to the plasma membrane by a glycosylphosphatidylinositol (GPI) anchor.  Over the past decade, fruit fly Drosophila has been used as a powerful model system to examine the functions of HSPGs in cell signaling and development.  There are two members of Drosophila glypicans named division abnormally delayed (Dally) and Dally-like (Dlp).  To study the functions of these two glypicans in development, we have generated the null mutants of dally and dlp.  Here, we describe the methods employed to analyze their functions in development with a focus on Dlp in the context of Wingless signaling.  Our data suggest that Dlp shows biphasic activity in Wingless/Wnt signaling and distribution.