MADS-box gene diversity in seed plants 300 million years ago
MADS-box gene diversity in seed plants 300 million years ago
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DOI：
10.1093/oxfordjournals.molbev.a026243
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发表时间：
2000-10-01
影响因子：
10.7
通讯作者：
Theissen, G
中科院分区：
文献类型：
--
作者：
Becker, A;Winter, KU;Theissen, G
MADS-box基因编码的转录因子家族控制着开花植物从根发育到花和果实发育的多种发育过程。通过系统发育重建，这些基因中的大多数可以细分为明确的单系基因分支，其成员具有相似的表达模式和功能。因此，基因枝多样性的建立可能是陆地植物进化过程中的一个重要事件。为了确定这些分支起源的时间，我们从裸子植物模式种、被子植物姐妹类群的代表——Gnetum gnemon中分离了19个不同的MADS-box基因。系统发育重建包括所有已发表的MADS-box基因，然后用于鉴定含有来自被子植物和裸子植物谱系的假定同源基因的基因枝。因此，确定了现存裸子植物和被子植物的最后共同祖先中已经存在的MADS-box基因的最小数量。涉及一对假定的同源基因的比较表达研究揭示了自被子植物和裸子植物谱系分离以来在很大程度上保守的模式多样性。综上所述，我们的数据表明至少已经有7种不同的MADS-box基因存在：在现存种子植物的基部大约300万年。这些基因在序列和功能上可能已经相当多样化了。此外，我们的数据表明，现存裸子植物和被子植物的MADS-box基因家族具有相似的复杂性。
MADS-box genes encode a family of transcription factors which control diverse developmental processes in flowering plants ranging from root development to flower and fruit development. Through phylogeny reconstructions, most of these genes can be subdivided into defined monophyletic gene clades whose members share similar expression patterns and functions. Therefore, the establishment of the diversity of gene clades was probably an important event in land plant evolution. In order to determine when these clades originated, we isolated cDNAs of 19 different MADS-box genes from Gnetum gnemon, a gymnosperm model species and thus a representative of the sister group of the angiosperms. Phylogeny reconstructions involving all published MADS-box genes were then used to identify gene clades containing putative orthologs from both angiosperm and gymnosperm lineages. Thus, the minimal number of MADS-box genes that were already present in the last common ancestor of extant gymnosperms and angiosperms was determined. Comparative expression studies involving pairs of putatively orthologous genes revealed a diversity of patterns that has been largely conserved since the time when the angiosperm and gymnosperm lineages separated. Taken together, our data suggest that there were already at least seven different MADS-box genes present: at the base of extant seed plants about 300 MYA. These genes were probably already quite diverse in terms of both sequence and function. In addition, our data demonstrate that the MADS-box gene families of extant gymnosperms and angiosperms are of similar complexities.