Fig. 3 Knockdown of sulf1 leads to decrease in muscle pioneer and medial fast fibers along the horizontal myoseptum. (A and B) Whole mounts of control (A) or sulf1 morphant fish (B) immunolabeled against Engrailed (green) and Prox1 (red), and counterstained with DAPI (blue). Controls have 3–4 muscle pioneers co-expressing Engrailed and Prox1 in each somite, surrounded by a halo of medial fast fibers that express only Engrailed and at weaker levels than the muscle pioneers. In sulf1 morphants, there are only 1–2 muscle pioneers and few medial fast fibers. (C and D) Brightfield view of the mediolateral stripe of melanocytes in control (C) or sulf1 morphant (D) zebrafish. Although control fish have a well-defined stripe of pigmentation that runs along the horizontal myoseptum, these pigment cells are absent in sulf1 morphants. Scale bars: A, B: 50 μm; C, D: 200 μm.
Reprinted from Developmental Biology, 378(2), Meyers, J., Planamento, J., Ebrom, P., Krulewitz, N., Wade, E., and Pownall, M.E., Sulf1 modulates BMP signaling and is required for somite morphogenesis and development of the horizontal myoseptum, 107-21, Copyright (2013) with permission from Elsevier. Full text @ Dev. Biol.