title: MADS-box genes in Ginkgo biloba and the evolution of the AGAMOUS family.
abstract: MADS-box proteins are a large family of transcription factors. In plants, many genes belonging to this family are involved in the homeosis of the floral system. Up to now, they have mainly been studied in angiosperms, especially in the model species Arabidopsis thaliana and Antirrhinum majus. We undertook a study of MADS-box genes in Ginkgo biloba, the unique extant representative of a whole branch of the phylogenetic tree of the seed plants. A polymerase chain reaction (PCR) survey reveals the diversity of MADS-box genes present in the genome of the Ginkgo. Duplications probably occurred specifically in the ginkgophyte lineage. Phylogenetic analyses revealed that one of these genes, GBM5, is an orthologue of the AGAMOUS gene of A. thaliana. We cloned and sequenced the entire cDNA of the GBM5 gene and studied its intron/exon structure. We showed by reverse transcriptase-PCR that it is expressed in both floral and vegetative tissues. We discuss the molecular evolution of the AGAMOUS family of genes.
authors.affiliation: Service de Biosystématique, Université P et M Curie, Paris, France.
authors.forename: Muriel
authors.initials: M
authors.lastname: Jager
authors.forename: Alexandre
authors.initials: A
authors.lastname: Hassanin
authors.forename: Michael
authors.initials: M
authors.lastname: Manuel
authors.forename: Hervé
authors.initials: H
authors.lastname: Le Guyader
authors.forename: Jean
authors.initials: J
authors.lastname: Deutsch
mesh_terms: D000595:Amino Acid Sequence; D002874:Chromosome Mapping; D017931:DNA Primers; D004587:Electrophoresis, Agar Gel; D019143:Evolution, Molecular; D005091:Exons / Q000235:genetics; D015870:Gene Expression; D020131:Genes, Duplicate / Q000235:genetics; D020441:Ginkgo biloba / Q000235:genetics*; D007438:Introns / Q000235:genetics; D026161:MADS Domain Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D017931:DNA Primers; D026161:MADS Domain Proteins