VMZ explants were dissected from embryos at onset of gastrulation (stage 10) and analyzed for ventroposterior (left panels) or dorsoanterior (right panels) marker expression by quantitative real-time RT-PCR (Methods). Ventroposterior and dorsoanterior marker gene expression levels were normalized to uninjected VMZ or DMZ tissues, respectively. Experiments are the cumulative results of 3 independent experiments, each with at least 3 biological replicates. Error bars indicate SD and p-values were calculated by Student’s T-test. Note that N1 alone reduces expression of Xpo, Vent1 and Vent2 indicating a dorsoanteriorizing effect but that induction of dorsoanterior markers Gsc, Chd, and ADMP occurs only in presence of tBR. Xnr3 is not induced by N1 either alone or with tBR.