In wild type blastula (Control), Notch down-regulates nuclear TCF in mesoderm, indicated by the white bracket (A to C). Without Notch (Notch MASO, D to F) or NLK (NLK MASO, G-I), nuclear TCF persists in the mesoderm. Note. Adapted from “Sequential Signaling Crosstalk Regulates Endomesoderm Segregation in Sea Urchin Embryos,” by A. J. Sethi et al., 2012, Science, 335, p. 590-593. Copyright 2012 by AAAS.