Transcription level of Ey directly regulates βh0. (A) Representative gel of βh0 expression in e10.5 wild-type and TR2/TR4 transgenic yolk sacs. Genotype of each sample is marked above the gel, and 2 TR2/TR4 transgenic lines are noted as line 1s and 2. All samples were digested with BslI. (B) Quantitation of βh0 expression in e10.5 wild-type and 2 different TR2/TR4 transgenic lines. Error bars represent SD of at least 3 embryos of that genotype.