title: Ancient asymmetries in the evolution of flowers.
abstract: Dorsoventral asymmetry in flowers is thought to have evolved many times independently as a specialized adaptation to animal pollinators. To understand how such a complex trait could have arisen repeatedly, we have compared the expression of a gene controlling dorsoventral asymmetry in Antirrhinum with its counterpart in Arabidopsis, a distantly related species with radially symmetrical flowers. We found that the Arabidopsis gene is expressed asymmetrically in floral meristems, even though they are destined to form symmetrical flowers. This suggests that, although the flowers of the common ancestor were probably radially symmetrical, they may have had an incipient asymmetry, evident at the level of early gene activity, which could have been recruited many times during evolution to generate asymmetric flowers.
authors.affiliation: Centro Nacional de Biotecnología/Instituto de Investigaciones Agrarias, Departamento de Biología Molecular de Plantas, Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain. pcubas@cnb.uam.es
authors.forename: P
authors.initials: P
authors.lastname: Cubas
authors.forename: E
authors.initials: E
authors.lastname: Coen
authors.forename: J M
authors.initials: JM
authors.lastname: Zapater
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development*; D005075:Biological Evolution; D004268:DNA-Binding Proteins; D018506:Gene Expression Regulation, Plant; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics; D018749:RNA, Plant / Q000096:biosynthesis; D014157:Transcription Factors
chemical_list: D004268:DNA-Binding Proteins; D010940:Plant Proteins; D018749:RNA, Plant; D014157:Transcription Factors; C101995:cycloidea protein, Antirrhinum