Upregulation of genes involved in epigenetic modifications during intestinal stem cell development. (A) HDAC activity. Intestinal protein extracts were prepared from Xenopus laevis tadpoles at different stages and assayed for HDAC activity in the presence or absence of 10 nM TSA, an HDAC inhibitor. Means +/- SEMs are given. Statistical significance as compared with the stage 54 animals is expressed as *: P <0.01. Note that the HDAC-specific drug TSA inhibited all activities. See for details. (B)-(D). The relative mRNA levels of N-CoR (B), PRMT1 (C), and Dot1L (D). The mRNA levels were determined by using total RNA from intestine at different stages during Xenopus laevis development. See[76, 87, 98] for details.