Fig. 3

Multiple 2,6-di-tert-butylphenols with aliphatic groups equal to or larger than an ethyl moiety at C4 potentiate T3-activation of an integrated TH-driven luciferase reporter in 1-week-post-fertilization tadpoles. 25 nM T3 caused significant activation compared to vehicle controls, independent of butylphenol status (shown for the T3-only group for clarity). Statistics were calculated as stated in the methods. ***p < 0.001; ****p < 0.0001. Chemical abbreviations are shown in Table 2.