RNA polymerase II phosphorylation at serine 2 and histone H3 tri-methylation at lysine 36 are key steps for thyroid hormone receptor β gene activation by thyroid hormone in Rana catesbeiana tadpole liver

► Thyroid hormone up-regulated its receptor (TR) gene in the tadpole liver. ► Histone H3-K9 acetylation and -K36 trimethylation levels increased on TR gene. ► Phosphorylation level of serine 2 in RNA PolII correlated with these changes.