Apparent homology of expressed genes from wood-forming tissues of loblolly pine (Pinus taeda L.) with Arabidopsis thaliana
Apparent homology of expressed genes from wood-forming tissues of loblolly pine (Pinus taeda L.) with Arabidopsis thaliana
复制标题
DOI：
10.1073/pnas.1132171100
复制
发表时间：
2003-06-10
影响因子：
11.1
通讯作者：
Sederoff, R
中科院分区：
文献类型：
--
作者：
Kirst, M;Johnson, AF;Sederoff, R
火炬松（Pinus taeda L.）和拟南芥（Arabidopsis thaliana cliff）在形态、生态位、进化史和基因组大小方面差异很大。拟南芥是一种小型、草本、一年生双子叶植物，而松树是大型、长寿的针叶林树木。如此多样的植物可能在大量的功能基因上存在差异。从火炬松的成木组织中获得59,797个表达序列标签（est），并与拟南芥基因组全序列推断的基因序列进行比较。在公共数据库中，大约50%的松树ESTs在拟南芥或任何其他被子植物中没有明显的同源物。当使用含有长，高质量序列的contigs进行评估时，我们发现这两个物种的推断基因之间具有更高水平的表观同源性。在1100 bp或更长的序列中，大约90%的序列具有明显的拟南芥同源性（E值< 10(-10)）。松树和拟南芥最后一次拥有共同的祖先是在大约3亿年前。如果没有基本功能，很少有基因会在这段时间内保持高度的序列相似性。这些观察结果表明种子植物中存在大量的基因序列保存。
Pinus taeda L. (loblolly pine) and Arabidopsis thaliana cliff er greatly in form, ecological niche, evolutionary history, and genome size. Arabidopsis is a small, herbaceous, annual dicotyledon, whereas pines are large, long-lived, coniferous forest trees. Such diverse plants might be expected to differ in a large number of functional genes. We have obtained and analyzed 59,797 expressed sequence tags (ESTs) from wood-forming tissues of loblolly pine and compared them to the gene sequences inferred from the complete sequence of the Arabidopsis genome. Approximately 50% of pine ESTs have no apparent homologs in Arabidopsis or any other angiosperm in public databases. When evaluated by using contigs containing long, high-quality sequences, we find a higher level of apparent homology between the inferred genes of these two species. For those contigs 1,100 bp or longer, approximate to90% have an apparent Arabidopsis homolog (E value < 10(-10)). Pines and Arabidopsis last shared a common ancestor approximate to300 million years ago. Few genes would be expected to retain high sequence similarity for this time if they did not have essential functions. These observations suggest substantial conservation of gene sequence in seed plants.