(A) Volcano plot of dysregulated genes in Pea3 mutant lacrimal gland buds. Red dots highlight Six1, Six2 and other known targets of FGF signaling down regulated in Pea3 mutants. (B) Pea3 binding sites were presented in the Six1 and Six2 loci as shown by analysis of ChIP-seq datasets. (C) Both Six1 and 2 were downregulated in Pea3 and Fgfr2 mutants. Scale bar, 50μm. (D) Quantitative-PCR demonstrated that siRNA reduced the expressions of Six1 and Six2. Student’s t test, *P<0.01, **P<0.0001, n = 3. (E-F) siRNA knockdown of Six1 and Six2 synergistically disrupted lacrimal gland development in explant lacrimal gland cultures (Mean lacrimal gland sizes relative to control + s.e.m. are shown. One-way ANOVA test, *P<0.05, **P<0.02, n = 3 for each condition).