The origins of Arabidopsis suecica (Brassicaceae) as indicated by nuclear rDNA sequences
The origins of Arabidopsis suecica (Brassicaceae) as indicated by nuclear rDNA sequences
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DOI：
10.2307/2419615
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发表时间：
1996-10-01
影响因子：
1
通讯作者：
AlShehbaz, IA
中科院分区：
文献类型：
--
作者：
OKane, SL;Schaal, BA;AlShehbaz, IA
直接测序的核rDNA内转录间隔区序列（ITS）从拟南芥（Arabidopsis suecica）表明，至少有两种类型的ITS存在于这个allopolypoid物种的个人。克隆PCR扩增的ITS序列并测序证实A. suerica含有两种不同类型的ITS序列，一种来自A. thaliana，另一种来自沙豆蔻（Cardaminopsis arenosa）或C.忽略。根据这些数据和生态学原理，A. thaliana和C. arenosa是A.苏西卡这些结果支持了其他研究采用cpDNA限制性位点，细胞学，和等电聚焦的Rubisco。没有观察到重组或ITS协同进化的证据，这表明通过协同进化的rDNA重复序列的均一化在染色体内比在染色体之间更有效，或者，由于A. suecica，没有足够的时间来使ITS序列均匀化。这两种现象都可能是造成A.苏西卡
Direct sequencing of nuclear rDNA internal transcribed spacer sequences (ITS) from Arabidopsis suecica showed that at least two ITS types were present in individuals of this allopolypoid species. Cloning PCR-amplified ITS sequences and subsequent sequencing confirms that A. suerica contains two distinct types of ITS sequences, one from A. thaliana and the other from either Cardaminopsis arenosa or C. neglecta. Based on these data and on ecology, A. thaliana and C. arenosa are the putative parents of A. suecica. These results support those of other studies employing cpDNA restriction sites, cytology, and isoelectric focusing of Rubisco. No recombination or evidence of concerted evolution of the ITS was observed, suggesting either that homogenization of rDNA repeats through concerted evolution is more efficient within rather than among chromosomes, or that, because of the recent origin of A. suecica, insufficient time has elapsed to allow ITS sequences to be homogenized. Both of these phenomena may be responsible for the observed pattern of ITS variation in A. suecica.