Screening for mRNA expression of mesodermal growth factors and their receptor. (A) Processing of endogenous Ihh in mammalian cells. Palmitoyl modification of the N-terminal fragment was essential for potentiating hedgehog activity. This occurs after autocatalytic processing of the signal peptide in cells. The C-terminal fragment of the Indian hedgehog protein displays an autoproteolytic activity and a cholesterol transferase activity, whereas the C-terminal product has no signaling activity. The cholesterol moiety of Ihh contributes to restriction of the spatial distribution of Ihh protein to the cell surface. (B) The mRNA expression of Ihh and receptor molecules. For detection of Ihh, a primer pair specific for endogenous Ihh was used. Lane 1, human umbilical vein endothelial cells (HUVECs); lane 2, primary stromal cells; lane 3, hTERT stromal cells; lane 4, cord blood; lane 5, H₂O. (C) The mRNA expression of hedgehog receptor molecules in CB: lane 1, total cord blood RT⁺; lane 2 CD34⁺RT⁺, lane 3 CD34⁺RT^–.