title: Developmentally regulated expression of Shh and Ihh in the developing mouse cranial base: comparison with Sox9 expression.
abstract: The cranial base, located between the cranial vault and the facial bones, plays an important role in integrated craniofacial development and growth. Transgenic Shh and Sox9-deficient mice show similar defects in cranial base patterning. Therefore, in order to examine potential interactions of Shh, Ihh, another member of the Hh family, and Sox9 during cranial base development and growth, we investigated their cellular mRNA expression domains in the embryonic (E) and early postnatal (PN) cranial base from E10 to PN5 using sectional radioactive 35-S in situ hybridization. Of the Hhs, Shh was observed in the foregut epithelium and the notochord, while Sox9 showed broad expression in the loose mesenchyme of the cranial base area during E10-E11. Subsequently, from E12 onward, all genes were observed in the developing cranial base, and after birth the genes were prominently colocalized in the prehypertrophic chondrocytes of the synchondroses. Collectively, these data suggest that Hh-Sox9 auto- and paracrine signaling interactions may provide a critical mechanism for regulating the patterning of the cranial base as well as for its development and growth.
authors.affiliation: Section of Anatomy and Cell Biology, Department of Biomedicine, University of Bergen, Bergen, Norway.
authors.forename: Xuguang
authors.initials: X
authors.lastname: Nie
authors.forename: Keijo
authors.initials: K
authors.lastname: Luukko
authors.forename: Inger Hals
authors.initials: IH
authors.lastname: Kvinnsland
authors.forename: Päivi
authors.initials: P
authors.lastname: Kettunen
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001846:Bone Development / Q000235:genetics; D001842:Bone and Bones / Q000196:embryology / Q000378:metabolism; D004622:Embryo, Mammalian; D047108:Embryonic Development; D018507:Gene Expression Regulation, Developmental; D005865:Gestational Age; D053823:Hedgehog Proteins; D006609:High Mobility Group Proteins / Q000235:genetics* / Q000378:metabolism; D017403:In Situ Hybridization; D051379:Mice; D008815:Mice, Inbred Strains; D010012:Osteogenesis / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D055758:SOX9 Transcription Factor; D019291:Skull Base / Q000196:embryology* / Q000254:growth & development* / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D053823:Hedgehog Proteins; D006609:High Mobility Group Proteins; D012333:RNA, Messenger; D055758:SOX9 Transcription Factor; C465570:Shh protein, mouse; C527933:Sox9 protein, mouse; D015534:Trans-Activators; D014157:Transcription Factors