Evolution of novelty in the cichlid dentition.
The shape of teeth occupies a central position in various biological disciplines, from paleo-ecology to molecular biology to cosmetic and reconstructive dentistry. Despite a long tradition of study in mammals, important questions remain regarding the genetic and developmental basis of differences in tooth shape. Here, we use natural mutants of cichlid fish from East Africa, which exhibit tremendous dental diversity, to help fill the gaps in our understanding of vertebrate odontogenesis. We employ an expanded genetic linkage map to demonstrate that cusp number segregates as a gene of major effect, which explains approximately 40% of the phenotypic variance, on cichlid chromosome 5. Furthermore, we examine patterns of Bmp4 expression in early odontogenesis to address and refine predictions of models linking tooth shape and tooth number. Mutations in the Bmp4 cistron do not control tooth shape in this mapping cross. Our data suggest that the evolution of novelty in the cichlid dentition is galvanized by a small number of genetic changes, echoing similar conclusions from recent studies of other vertebrate adaptive morphologies.
School of Biology, Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332-0230, USA. todd.streelman@biology.gatech.edu
Jeffrey Todd
JT
Streelman
R Craig
RC
Albertson
D000818:Animals; D005075:Biological Evolution; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000096:biosynthesis / Q000502:physiology; D002874:Chromosome Mapping / Q000662:veterinary; D023681:Cichlids / Q000033:anatomy & histology* / Q000235:genetics; D020869:Gene Expression Profiling / Q000662:veterinary; D014644:Genetic Variation; D017403:In Situ Hybridization / Q000662:veterinary; D009154:Mutation / Q000235:genetics* / Q000502:physiology; D009805:Odontogenesis / Q000235:genetics / Q000502:physiology*; D010641:Phenotype; D040641:Quantitative Trait Loci / Q000235:genetics; D014070:Tooth / Q000033:anatomy & histology*
D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins