FGF signalling regulates expression of <i>osx</i>.

<p>(A-H) Larvae were treated at 48hpf, fixed at 51hpf and expression of several bone markers was analysed by in situ hybridisation. Arrowheads point to the opercle in the high magnification images to the right of each panel. Expression of <i>runx2a</i> (A-D) and <i>runx2b</i> (E-H) is unchanged after inhibition of FGF signalling using <i>hs</i>:<i>dnfgfr1</i> larvae as well as over activation in <i>hs</i>:<i>fgf3</i> transgenic fish. Expression of <i>runx2b</i> is slightly reduced after SU5402 treatment (F). (I-L) Expression of <i>osx</i> is decreased after inhibition of FGF signalling and increased after over activation of FGF signalling as shown by in situ hybridization. Abbreviations: cl = cleithrum, op = opercle. Scale bar = 200μM. (M) Quantification for presence or absence of <i>osx</i> staining in the opercle from I-L. Expression was normalised to the control. (N) qPCR performed in parallel to I-L confirm effects of FGF signalling on <i>osx</i> expression. Treatments were normalised to <i>gapdh</i>. Treatment with SU5402 showed a significant reduction (p<0.05 Student's t-test).