Utility and distribution of conserved noncoding sequences in the grasses
Utility and distribution of conserved noncoding sequences in the grasses
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DOI：
10.1073/pnas.052139599
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发表时间：
2002-04-30
影响因子：
11.1
通讯作者：
Freeling, M
中科院分区：
文献类型：
--
作者：
Kaplinsky, NJ;Braun, DM;Freeling, M
基因表达的控制需要顺式作用的调控DNA序列。从历史上看，这些序列一直很难识别。最近，通过跨物种基因组DNA比较，在哺乳动物基因中发现了保守的非编码序列，其中一些被证明是调节序列。利用序列比对算法，比较了玉米和水稻两种牧草的非编码基因IG1的基因组DNA序列，发现了IG1中的几个CNS。这些CNS存在于多种草本植物中，它们代表着不同的系统发育谱系。对其他6个玉米/水稻基因进行了比较，其中5个基因含有CNSS。根据核苷酸替代率，这些CNS之所以存在，是因为它们具有生物学功能。我们的分析表明，草的CNS比哺乳动物基因中的CNS更小，频率更低，哺乳动物的基因调控可能比草的基因调控更复杂。CNSS是一种优秀的基于泛草基因定位的遗传作图工具。它们应该在系统发育研究中作为特征有用，并作为基因调控复杂性的监测器。
Control of gene expression requires cis-acting regulatory DNA sequences. Historically these sequences have been difficult to identify. Conserved noncoding sequences (CNSs) have recently been identified in mammalian genes through cross-species genomic DNA comparisons, and some have been shown to be regulatory sequences. Using sequence alignment algorithms, we compared genomic noncoding DNA sequences of the liguleless1 (Ig1) genes in two grasses, maize and rice, and found several CNSs in Ig1. These CNSs are present in multiple grass species that represent phylogenetically disparate lineages. Six other maize/rice genes were compared and five contained CNSs. Based on nucleotide substitution rates, these CNSs exist because they have biological functions. Our analysis suggests that grass CNSs are smaller and far less frequent than those identified in mammalian genes and that mammalian gene regulation may be more complex than that of grasses. CNSs make excellent pan-grass PCR-based genetic mapping tools. They should be useful as characters in phylogenetic studies and as monitors of gene regulatory complexity.