Different expression patterns of Gli1-3 in mouse embryonic maxillofacial development

The Sonic hedgehog (. SHH) signaling pathway plays many key roles in the development of . Drosophila and vertebrate embryos, including regulating craniofacial development. The . GLI family of transcription factors (. GLI1, . 2, and . 3) mediates the . SHH morphogenetic signal by regulating the expression of downstream target genes. Signaling aberrations seriously affect vertebrate development. To better understand the regulation of . GLI transcription factors, we investigated the expression patterns of . Gli1-3 during murine embryonic craniofacial development using . in situ hybridization with whole-mounts and sections and quantitative real-time PCR. We found that . Gli1 expression was mostly detected in the mesenchyme in embryonic dermis, and strongly detected in embryonic oral mucosa at late stages of face development. . Gli2 was strong in mesenchyme, both in dermis and oral mucosa. . Gli3 expression was detected fainter in the epithelium than the mesenchyme at 11 days post-coitum (dpc), but at 14.5. dpc, expression was stronger in the epithelium. Of the three genes, . Gli1 expression was highest in early stages of face development, . Gli3 expression was highest in the second half of facial development (and remained stable thereafter), whereas . Gli2 expression remained low throughout facial development. The present findings suggest that . Gli1-3 may play different roles during facial development.