title: The Dlx genes as clues to vertebrate genomics and craniofacial evolution.
abstract: The group of Dlx genes belongs to the homeobox-containing superfamily, and its members are involved in various morphogenetic processes. In vertebrate genomes, Dlx genes exist as multiple paralogues generated by tandem duplication followed by whole genome duplications. In this review, we provide an overview of the Dlx gene phylogeny with an emphasis on the chordate lineage. Referring to the Dlx gene repertoire, we discuss the establishment and conservation of the nested expression patterns of the Dlx genes in craniofacial development. Despite the accumulating genomic sequence resources in diverse vertebrates, embryological analyses of Dlx gene expression and function remain limited in terms of species diversity. By supplementing our original analysis of shark embryos with previous data from other osteichthyans, such as mice and zebrafish, we support the previous speculation that the nested Dlx expression in the pharyngeal arch is likely a shared feature among all the extant jawed vertebrates. Here, we highlight several hitherto unaddressed issues regarding the evolution and function of Dlx genes, with special reference to the craniofacial development of vertebrates.
authors.affiliation: Laboratory for Evolutionary Morphology, Center for Developmental Biology, RIKEN, 2-2-3 Minatojimaminami-machi, Chuo-ku, Kobe 650-0047, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Takechi
authors.forename: Noritaka
authors.initials: N
authors.lastname: Adachi
authors.forename: Tamami
authors.initials: T
authors.lastname: Hirai
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kuratani
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Kuraku
mesh_terms: D000818:Animals; D005075:Biological Evolution; D018507:Gene Expression Regulation, Developmental; D023281:Genomics; D018398:Homeodomain Proteins / Q000235:genetics*; D008954:Models, Biological; D012886:Skull / Q000033:anatomy & histology / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics*; D014714:Vertebrates / Q000235:genetics*
chemical_list: C088334:Distal-less homeobox proteins; D018398:Homeodomain Proteins; D014157:Transcription Factors