Fig. 1. CTGF and its expression pattern. (A) Schematic representation of the domain structure of CTGF. Shown below is an alignment of the CT domains of xCTGF, XCyr61, XSlit and XWiseA. The eight conserved cysteines are indicated by a dot and amino acids conserved in at least three out of the four proteins are shaded grey. The CT domain of xCTGF shows 52% amino acid identity with XCyr61, 27% with Xslit, and 19% with XWiseA. (B) Temporal expression pattern of Ctgf studied by reverse transcription-polymerase chain reaction. Stages are according to Nieuwkoop and Faber (Nieuwkoop and Faber, 1975). Ornithine decarboxylase (ODC) acts as a loading control. Note the absence of maternal expression of CTGF. (C-H) In situ hybridisation analysis of CTGF expression. (C) Stage 20. Expression is detectable in the somites and axial midline. (D) Stage 25. Expression persists in somites and axial midline. (E) Stage 28. Expression is detectable in brain and branchial arches. (F) Stage 32. CTGF is expressed in the heart, in distinct domains in the brain, in the floorplate and in the hypochord. (G,H) Sections through a stage 32 embryo confirm expression of Ctgf in floorplate, heart and somites. CT, C-terminal cystine knot; IGFB, Insulin growth factor binding domain; Signal, signal peptide; TSP-1, thromospondin type 1 repeat; CR, Von Willebrand type C repeat.