Dual-fluorescence transgenic analysis of IRF6 enhancer MCS-9.7 where a SNP (rs642961, G>A) in a TFAP2A (AP2α) binding site has been associated with cleft lip.

<p><b>(A)</b> Regulatory landscape of IRF6, depicting the location of MCS-9.7 enhancer. The conservation plot on the right shows the absence of sequence conservation for MCS-9.7 in the zebrafish genome. <b>(B)</b> IRF6-MCS-9.7 enhancer-driven F1 reporter transgenics. The Wt(G) allele drives expression in the first pharyngeal arch (PA1) (arrow) and in the developing ethmoid plate (EP) (curved arrow). Mut(A) has lost EP expression but maintains PA1 expression. <b>(C)</b> RNA <i>in situ</i> hybridisation analysis of zebrafish <i>irf6</i> at 72hpf showing overlap of the reporter gene expression domain driven by Wt(G) allele with the endogenous <i>irf6</i> expression pattern in the developing jaw. Wt: wild-type; Mut: mutant; hpf: hours post fertilization.