title: Gene expression analysis of canonical Wnt pathway transcriptional regulators during early morphogenesis of the facial region in the mouse embryo.
abstract: Structures and features of the face, throat and neck are formed from a series of branchial arches that grow out along the ventrolateral aspect of the embryonic head. Multiple signalling pathways have been implicated in patterning interactions that lead to species-specific growth and differentiation within the branchial region that sculpt these features. A direct role for Wnt signalling in particular has been shown. The spatial and temporal distribution of Wnt pathway components contributes to the operation of the signalling system. We present the precise distribution of gene expression of canonical Wnt pathway transcriptional regulators, Tcf1, Lef1, Tcf3, Tcf4 and beta-catenin between embryonic day (E) 9.5 and 11.5. In situ hybridization combined with Optical Projection Tomography was used to record and compare distribution of transcripts in 3D within the developing branchial arches. This shows widespread yet very specific expression of the gene set indicating that all genes contribute to proper patterning of the region. Tcf1 and Lef1 are more prominent in rostral arches, particularly at later ages, and Tcf3 and Tcf4 are in general expressed more deeply (medial/endodermal aspect) in the arches than Tcf1 and Lef1. Comparison with Wnt canonical pathway readout patterns shows that the relationship between the expression of individual transcription factors and activation of the pathway is not simple, indicating complexity and flexibility in the signalling system.
authors.affiliation: Department of Zoology, School of Natural Sciences, Trinity College Dublin, Ireland.
authors.forename: Victor
authors.initials: V
authors.lastname: Vendrell
authors.forename: Kristen
authors.initials: K
authors.lastname: Summerhurst
authors.forename: James
authors.initials: J
authors.lastname: Sharpe
authors.forename: Duncan
authors.initials: D
authors.lastname: Davidson
authors.forename: Paula
authors.initials: P
authors.lastname: Murphy
mesh_terms: D000818:Animals; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D019521:Body Patterning / Q000235:genetics; D004622:Embryo, Mammalian / Q000196:embryology / Q000378:metabolism*; D005145:Face / Q000196:embryology; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D051538:Hepatocyte Nuclear Factor 1-alpha / Q000235:genetics; D017403:In Situ Hybridization / Q000379:methods; D051821:Lymphoid Enhancer-Binding Factor 1 / Q000235:genetics; D008297:Male; D051379:Mice; D009024:Morphogenesis; D009419:Nerve Tissue Proteins / Q000235:genetics; D011247:Pregnancy; D015398:Signal Transduction / Q000235:genetics*; D051820:TCF Transcription Factors / Q000235:genetics; D013997:Time Factors; D014054:Tomography / Q000379:methods; D015534:Trans-Activators / Q000235:genetics*; D000073940:Transcription Factor 4; D058125:Transcription Factor 7-Like 1 Protein; D051153:Wnt Proteins / Q000502:physiology*; D051176:beta Catenin / Q000235:genetics
chemical_list: D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D051538:Hepatocyte Nuclear Factor 1-alpha; C496488:Hnf1a protein, mouse; C497574:Lef1 protein, mouse; D051821:Lymphoid Enhancer-Binding Factor 1; D009419:Nerve Tissue Proteins; D051820:TCF Transcription Factors; C090743:Tcf4 protein, mouse; C544913:Tcf7l1 protein, mouse; D015534:Trans-Activators; D000073940:Transcription Factor 4; D058125:Transcription Factor 7-Like 1 Protein; D051153:Wnt Proteins; D051176:beta Catenin