Genetic approaches in the study of heparan sulfate functions in Drosophila

Several classes of heparan sulfate proteoglycan (HSPG) core proteins and all HS biosynthetic/modifying enzymes are evolutionarily conserved from human to Drosophila melanogaster. This genetically tractable model offers highly sophisticated techniques to manipulate gene function in a spatially and temporally controlled manner. Thus, Drosophila has been a powerful system to explore the functions of HSPGs in vivo. In this chapter, we will introduce two genetic techniques available in Drosophila: TARGET (temporal and regional gene expression targeting) and MARCM (mosaic analysis with a repressible cell marker).