Fig. 6. Pitx3 specifically interacts with a highly conserved region in proximity of the Ahd2 transcription start site. (A) Genomic positions of a selection (regions 2, 4 and 5) of the conserved putative Pitx3-binding sites that were selected for PCR-based analysis in a ChIP assay. (B) ChIP assay with either Pitx3 antibody or control rabbit immunoglobulins (IgG), with input chromatin as positive control. Genomic region 5 is specifically amplified from the Pitx3 ChIP sample. No amplification was observed for the previously described Pitx3-binding site (region 2) (Chung et al., 2005) or genomic region 4. Also, a randomly chosen genomic region (Control) showed no amplification. (C) Comparison of genomic region 5 between mouse, rat and human, showing high sequence conservation (gray) and a fully conserved non-consensus putative Pitx3-binding site amongst species (black).