title: Dlx2 over-expression: a possible mechanism for first branchial arch malformation.
abstract: The first branchial arch malformation (FBAM) is a rare congenital defect associated with anomalous development of the first and second branchial arches. Cause of FBAM still remains unknown, and is thought in most cases to be multifactorial, involving both genetic and enviromental factors. Dlx2 as a member of the Dlx homeobox gene family, plays a crucial role in the development of the first branchial arch. The tissues regulated mainly by Dlx2 are coincident with the tissues mainly involved in FBAM. Dlx2 over-expression generated by electroporation transfection can disturb the migration and differentiation of cranial neural crest cells (CNCCs), which migrate to the branchial arches and in turn give rise to much of the facial skeleton and connective tissues. Furthermore, Dlx2 over-expression can be found in the first branchial arch spontaneous mutant mice. So we hypothesize that Dlx2 over-expression mutation causes FBAM due to an increase in cell-cell adhesion and inhibiting the migration of CNCC to the first branchial arch in the early stage, or migrating to an incorrect position and can't differentiate into normal tissues. What an exact role of Dlx2 over-expression in FBAM remains to be investigated and Dlx2 over-expression transgenic mouse will be a nice model for further research in FBAM.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology. Shanghai 200011, China. daijiewen@163.com
authors.forename: Jie-wen
authors.initials: JW
authors.lastname: Dai
authors.forename: Xu-dong
authors.initials: XD
authors.lastname: Wang
authors.forename: Hao
authors.initials: H
authors.lastname: Sun
authors.forename: Wen-hui
authors.initials: WH
authors.lastname: Jiang
authors.forename: Jing-ting
authors.initials: JT
authors.lastname: Lu
authors.forename: Guo-fang
authors.initials: GF
authors.lastname: Shen
mesh_terms: D000818:Animals; D001934:Branchial Region / Q000002:abnormalities*; D002454:Cell Differentiation; D018507:Gene Expression Regulation, Developmental; D051379:Mice; D009432:Neural Crest