title: Morphing the hyomandibular skeleton in development and evolution.
abstract: How might changes in developmental regulatory pathways underlie evolutionary changes in morphology? Here we focus on a particular pathway regulated by a secreted, signaling peptide, Endothelin1 (Edn1). Developmental genetic analyses show the Edn1-pathway to be crucial for hyomandibular patterning, and we discuss our work with zebrafish suggesting how the signal may function in regulating numbers of skeletal elements, their sizes and their shapes. We then review a broader collection of comparative studies that examine morphological evolution of a subset of the same skeletal elements-the opercular-branchiostegal series of bones of the hyoid arch. We find that phenotypic changes in zebrafish mutants copy evolutionary changes that recur along many actinopterygian lineages. Hence the developmental genetic studies are informative for providing candidate pathways for macroevolution of facial morphology, as well as for our understanding of how these pathways work.
authors.affiliation: Institute of Neuroscience, University of Oregon, Eugene, Oregon, USA. kimmel@uoneuro.uoregon.edu
authors.forename: Charles B
authors.initials: CB
authors.lastname: Kimmel
authors.forename: Macie B
authors.initials: MB
authors.lastname: Walker
authors.forename: Craig T
authors.initials: CT
authors.lastname: Miller
mesh_terms: D000818:Animals; D005075:Biological Evolution; D019521:Body Patterning / Q000235:genetics*; D004625:Embryo, Nonmammalian; D047108:Embryonic Development; D019332:Endothelin-1 / Q000502:physiology; D006928:Hyoid Bone / Q000254:growth & development*; D008334:Mandible / Q000254:growth & development*; D015027:Zebrafish / Q000235:genetics / Q000254:growth & development*; D029961:Zebrafish Proteins / Q000502:physiology
chemical_list: D019332:Endothelin-1; D029961:Zebrafish Proteins; C414282:edn1 protein, zebrafish