K02288 induces dorsalization of zebrafish embryos.

(A) Brightfield photographs of 26 hours old Tg(BRE:mRFP) transgenic embryos treated with DMSO or varying doses of K02288 from the 8- to 16-cell stage. Severity of the dorsalization correlated with the dose of K02288. Very strong dorsalized phenotypes were observed with 8–10 µM K02288. (B) The phenotypes of the embryos shown in A were classified according to Kishimoto et al. [49]. (C) Western blot for mRFP in extracts prepared from Tg(BRE:mRFP) embryos treated in a parallel experiment. Loss of mRFP protein was evident at 8–10 µM K02288. As a control, the effects of dorsomorphin (DM) and LDN-193189 (LDN) on mRFP expression are also shown. Protein loading control is shown with the MCM6 blot.