| Abstract: | Heparan sulfate proteoglycans(HSPGs) are critically involved in a variety of biological events.The functions of HSPGs are determined by the nature of the core proteins and modifications of heparan sulfate(HS) glycosaminoglycan(GAG) chains.The distinct O-sulfotransferases are important for nonrandom modifications at specific positions.Two HS 3-0 sulfotransferase(Hs3st) genes,Hs3st-A and Hs3st-B,were identified in Drosophila.Previous experiments using RNA interference(RNAi) suggested that Hs3st-B was required for Notch signaling.Here,we generated a null mutant of Hs3st-B via ends-out gene targeting and examined its role(s) in development.We found that homozygous Hs3st-B mutants have no neurogenic defects or alterations in the expression of Notch signaling target gene.Thus,our results strongly argue against an essential role for Hs3st-B in Notch signaling.Moreover,we have generated two independent Hs3st-A RNAi lines which worked to deplete Hs3st-A.Importantly,Hs3st-A RNAi combined with Hs3st-B mutant flies did not alter the expression of Notch signaling components,arguing that both Hs3st-A and Hs3st-B were not essential for Notch signaling.The establishment of Hs3st-B mutant and effective Hs3st-A RNAi lines provides essential tools for further studies of the physiological roles of Hs3st-A and Hs3st-B in development and homeostasis. |
