Summary of our results. Diagram showing the distribution of the different enhancers detected in this study within the IrxB cluster. For simplicity, we have numbered these enhancers from 1–22. These numbers reflect their linear position in the genome from Irx3 to Irx6. Enhancers tested in both systems have the same number. The correspondence of these numbers with the enhancer position in human genome can be found in Supplemental Table 2. The color coding represents the different expression domains in which these enhancers are active in zebrafish (top) and Xenopus (middle). These domains are listed in the same color code. Note that this is an oversimplification scheme, as many enhancers are active in subdomains of these territories. At bottom, an illustration shows the expression domains of zebrafish and Xenopus IrxB genes.
