Fulton Theresa M, Van der Hoeven Rutger, Eannetta Nancy T, Tanksley Steven D
Department of Plant Breeding, Cornell University, Ithaca, New York 14853, USA.
Plant Cell. 2002 Jul;14(7):1457-67. doi: 10.1105/tpc.010479.
We have screened a large tomato EST database against the Arabidopsis genomic sequence and report here the identification of a set of 1025 genes (referred to as a conserved ortholog set, or COS markers) that are single or low copy in both genomes (as determined by computational screens and DNA gel blot hybridization) and that have remained relatively stable in sequence since the early radiation of dicotyledonous plants. These genes were annotated, and a large portion could be assigned to putative functional categories associated with basic metabolic processes, such as energy-generating processes and the biosynthesis and degradation of cellular building blocks. We further demonstrate, through computational screens (e.g., against a Medicago truncatula database) and direct hybridization on genomic DNA of diverse plant species, that these COS markers also are conserved in the genomes of other plant families. Finally, we show that this gene set can be used for comparative mapping studies between highly divergent genomes such as those of tomato and Arabidopsis. This set of COS markers, identified computationally and experimentally, may further studies on comparative genomes and phylogenetics and elucidate the nature of genes conserved throughout plant evolution.
我们利用拟南芥基因组序列对一个大型番茄EST数据库进行了筛选，并在此报告鉴定出一组1025个基因（称为保守直系同源基因集或COS标记），这些基因在两个基因组中均为单拷贝或低拷贝（通过计算筛选和DNA凝胶印迹杂交确定），并且自双子叶植物早期分化以来，其序列一直保持相对稳定。这些基因已被注释，并且大部分可归类到与基本代谢过程相关的假定功能类别，如能量产生过程以及细胞组成成分的生物合成与降解。我们通过计算筛选（如与蒺藜苜蓿数据库比对）以及对多种植物物种的基因组DNA进行直接杂交进一步证明，这些COS标记在其他植物科的基因组中也保守。最后，我们表明，该基因集可用于高度分化的基因组（如番茄和拟南芥基因组）之间的比较作图研究。通过计算和实验鉴定出的这组COS标记，可能会推动比较基因组学和系统发育学的进一步研究，并阐明整个植物进化过程中保守基因的性质。
