Figure 4: Relative expression level of selected genes in 4-t-OP exposed Tg (fil-1: EGFP) zebrafish embryos were determined by real time PCR at 48 and 72 hpf. The expressions of the cardiovascular-related genes Nkx2.5, Nkx2.7, Hand2, Tbx2a, Tbx2b, Tbx5a, FGF1a, GATA-4, -5 and -6 were quantified. The data of the control group at 48 hpf was set as 1. The results represented triplicated experiments, and the different letters were considered significantly at p<0.05.