Figure 5.

Expression of Genes Encoding Regulators of the Tbx1 Gene, Genes Regulated by TBX1 Protein, and Genes Showing Genetic Interaction with the Tbx1 Locus

mRNA levels of genes as indicated assessed by RT-qPCR (A–E) and occupancy of gene loci as indicated by FOXA2 (F) and by the MOZ complex protein ING5 (G). Expression of the genes encoding the forkhead protein FOXA2 (A–C) reported to upregulate Tbx1 gene expression, as well as the Chd7 gene (E), reported to interact genetically with the Tbx1 locus, is unaffected by Moz mutation at E8.5 (A), E9.5 (B and E), and E10.5 (C). Tbx1 locus occupancy assessed by ChIP-qPCR by FOXA2 is increased in E9.5 Moz^−/− mutants (F; p = 0.015), albeit without being able to induce normal Tbx1 expression levels in the absence of MOZ (Figure 2). Expression of Foxc1 is increased at E8.5 (A, p = 0.04), and expression of Foxc1 and Foxc2 is decreased at E9.5 (B, p = 0.008 and p = 0.001, respectively) and E10.5 (C, p = 0.034 and p = 0.011, respectively) in Moz^−/− mutants without changes in occupancy of Foxc1 locus by ING5 (G; p = 0.251) and without occupancy of the Foxc2 locus by ING5 (data not shown). The expression of the Pitx2 gene, a target gene of TBX1, is decreased at E9.5 and E10.5 in Moz^−/− mutants (D, p = 0.023) without changes in ING5 occupancy of the Pitx2 locus (G). For the effects of Moz mutation, p values <0.05 and <0.01 are indicated by one and two asterisks, respectively. Data are presented and were analyzed as described in the Experimental Procedures. Data were derived from 48 embryos, n = 6 Moz^+/+ and 6 Moz^Δ/Δ per developmental stage (A–E) and 3 Moz^+/+ and 3 Moz^−/− (F and G).