Fig. 1

The gräte mutant phenotype is characterised by hypermineralisation in the skin and axial skeleton. (A) Alizarin Red staining of embryos at 8days post-fertilisation (dpf), demonstrating hypermineralisation along the vertebral column (arrowheads). Scale bar: 1mm. (B) Adult fish are viable, but feature a curved spine and reduced length. Scale bar: 1cm. (C) grt^-/- embryos (ventral view) with enhanced mineralisation in craniofacial elements (arrowheads). (D) Skin mineralisation is infrequently seen in grt^+/- and grt^-/- embryos (D′, ventral view). (E) Representative images showing the area quantified by the mineralisation assay used in this and in subsequent figures. (F) Vertebral mineralisation in grt^-/- embryos proceeds faster than in wild type, leading to (G) vertebral fusion from 6dpf onwards. (H,J) Alizarin Red staining at 6weeks post fertilisation (wpf) reveals a thickened, curved spine in grt^-/- fish; confocal images (I,K) of the boxed regions reveal mineralised nodules on the margins of the intervertebral space (arrowheads). Scale bars: 0.1mm.