Expression of smoothened in mouse embryonic maxillofacial development

Abstract

Hedgehog (Hh) signaling plays many key roles in the development of Drosophila and vertebrate embryos including regulation of craniofacial development. The seven-transmembrane protein, smoothened (Smo) transduces the Hh signal across the plasma membrane as an essential receptor of PTCHED1/2. There are few studies that evaluate the detailed expression of Smo in mouse embryonic craniofacial development. We investigated the expression patterns of Smo during murine embryonic craniofacial development using in situ hybridization (ISH), studies of whole-mounts and sections, immunohistochemistry, quantitative real time PCR, and Western blot analysis. We found that Smo mRNA was expressed in the face of mouse embryos at 11 and 12.5 days post coitum (dpc). After 13.5 dpc, the expression decreased to a low level and was faintly detected after birth. Smo protein could be detected also in embryos at 11, 12.5, and 14.5 dpc. After 15.5 dpc, the expression was very faint and paralleled the gene expression studies. No expression was detected in whisker follicle during facial development and faint signal was detected in Meckel's cartilage. These findings concerning Smo expression should guide further investigation of sonic Hh signaling pathway gene function during maxillofacial development.

Key words::

• maxillofacial development
• Meckel's cartilage
• Smo
• whisker follicle

Acknowledgments

This study was supported by grants from National Basic Research Program of China (973 program 2007CB947304 and 2010CB944801) and National Natural Science Foundation of China (30700962 and 81070798), Beijing New Star of Science & Technology (2008A081) Funding Project to Science Facility in Institutions of Higher Learning Under the jurisdiction of Beijing Municipality (PXM2011_014226_07_000066).

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.