|
Fig. S2 Osteoblast dedifferentiation does not depend on FGF signaling.
(A) FGF signaling is not required for ultrastructural changes in distal stump osteoblasts. Transmission electron micrographs of DMSO and SU5402 treated fins at 1 dpa. In DMSO treated fins, osteoblast nuclei (Nuc) have a rounded shape and are surrounded by extracellular matrix (ECM). In SU5402 treated fins osteoblast nuclei are equally rounded and cells are also surrounded by ECM. Epid = epidermis. Scalebar 2 μm.
(B) Gene expression levels in distal stump tissue in DMSO versus SU5402 treated fish at 1 dpa. FGF signaling is not required for endogenous runx2a, runx2b and osterix expression. Endogenous osteocalcin levels are not increased but reduced upon FGFR1 inhibition indicating that osteocalcin maintenance but not osteocalcin downregulation depends on FGF signaling. qRT-PCR on distal most stump segment tissue is shown. For each gene, the expression level is shown relative to the expression in the respective DMSO control. Error bars represent standard deviation of triplicates. nDMSO/SU5402 = 12 fish each.
(C) Induction of Tenascin in osteoblasts and fibroblast-like cells in the distal stump in response to amputation does not depend on FGF signaling. Anti-Tenascin antibody staining on sections of distal stump tissue of DMSO versus SU5402 treated fins at 1 dpa is shown. Osteoblasts are co-stained with anti-Zns 5 antibody. Tenascin protein is still expressed in the presence of SU5402. Scalebar is 20 μm. nDMSO = 5 fish with 33 sections. nSU5402 = 5 fish with 29 sections.
Reprinted from Developmental Cell, 20(5), Knopf, F., Hammond, C., Chekuru, A., Kurth, T., Hans, S., Weber, C.W., Mahatma, G., Fisher, S., Brand, M., Schulte-Merker, S., and Weidinger, G., Bone Regenerates via Dedifferentiation of Osteoblasts in the Zebrafish Fin, 713-724, Copyright (2011) with permission from Elsevier. Full text @ Dev. Cell