Jager Muriel, Hassanin Alexandre, Manuel Michael, Le Guyader Hervé, Deutsch Jean
Service de Biosystématique, Université P et M Curie, Paris, France.
Mol Biol Evol. 2003 May;20(5):842-54. doi: 10.1093/molbev/msg089. Epub 2003 Apr 2.
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.
MADS盒蛋白是一大类转录因子。在植物中，该家族的许多基因参与花器官系统的同源异型化。到目前为止，它们主要在被子植物中得到研究，尤其是在模式植物拟南芥和金鱼草中。我们对银杏中的MADS盒基因进行了研究，银杏是种子植物系统发育树中一个完整分支的唯一现存代表。聚合酶链反应（PCR）检测揭示了银杏基因组中存在的MADS盒基因的多样性。重复事件可能专门发生在银杏植物谱系中。系统发育分析表明，这些基因之一GBM5是拟南芥AGAMOUS基因的直系同源基因。我们克隆并测序了GBM5基因的完整cDNA，并研究了其内含子/外显子结构。我们通过逆转录PCR表明它在花组织和营养组织中均有表达。我们讨论了AGAMOUS基因家族的分子进化。
