Fig. 3.

Histone modifications associated with gene activation are increased at TR-target genes during T₃-induced metamorphosis. Premetamorphic tadpoles at stage 54 were treated with T₃ for 2 d. The intestine was isolated and subjected to a ChIP assay with anti-H3K4me3 (A), anti-H3K79me3 (B), or anti-H3R17me2a (C), anti-AcH3 (D), or anti-AcH4 antibody (E). ChIP signals were normalized with the ChIP signals of histone H3 in Fig. 2 for the corresponding promoter/exon regions. Error bars indicate sem (n = 3). A Student's t test was carried out between pairs of control and T₃-treated groups. The one and two stars indicate pairs of samples with significant differences (P < 0.05 and P < 0.01, respectively).