Loss of HDAC1 causes precocious differentiation into mesodermal and ectodermal lineages in EBs. Quantitative RT-PCR data for genes characteristic of undifferentiated stem cells (Oct-4, Nanog), endoderm (Gata4, Gata6), primitive ectoderm (Fgf5), mesoderm (Brachyury, Nkx2-5, Mef2c, and MyoD) and ectoderm (Nestin, βIII-tubulin) was performed as indicated on mRNA collected at days 0, 2, 4, 7, and 12 during EB differentiation. Mean values (n = 3) ± SEM are plotted. Values indicate expression of the specific gene relative to GAPDH measured using Universal ProbeLibrary hydrolysis probes. Data are representative of two independently tested clones for each genotype.