The glypican Dally-like is required for Hedgehog signalling in the embryonic epidermis of Drosophila.
The Drosophila genes dally and dally-like encode glypicans, which are heparan sulphate proteoglycans anchored to the cell membrane by a glycosylphosphatidylinositol link. Genetic studies have implicated Dally and Dally-like in Wingless signalling in embryos and imaginal discs. Here, we test the signalling properties of these molecules in the embryonic epidermis. We demonstrate that RNA interference silencing of dally-like, but not dally, gives a segment polarity phenotype identical to that of null mutations in wingless or hedgehog. Using heterologous expression in embryos, we uncoupled the Hedgehog and Wingless signalling pathways and found that Dally-like and Dally, separately or together, are not necessary for Wingless signalling. Dally-like, however, is strictly necessary for Hedgehog signal transduction. Epistatic experiments show that Dally-like is required for the reception of the Hedgehog signal, upstream or at the level of the Patched receptor.
Desbordes
Sabrina C
SC
Department of Genetics, University of Cambridge, Downing Street, Cambridge, CB2 3EH, UK.
Sanson
Bénédicte
B
D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D029721:Drosophila Proteins / Q000235:genetics*; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics*; D004625:Embryo, Nonmammalian / Q000502:physiology; D004817:Epidermis / Q000502:physiology; D017261:Glycosylphosphatidylinositols / Q000502:physiology; D053823:Hedgehog Proteins; D011509:Proteoglycans / Q000235:genetics*; D034741:RNA, Small Interfering / Q000235:genetics; D015398:Signal Transduction
D017931:DNA Primers; D029721:Drosophila Proteins; D017261:Glycosylphosphatidylinositols; D053823:Hedgehog Proteins; D011509:Proteoglycans; D034741:RNA, Small Interfering; C420997:dlp protein, Drosophila; C077245:hh protein, Drosophila