Lassner M, Dvorak J
Nucleic Acids Res. 1986 Jul 11;14(13):5499-512. doi: 10.1093/nar/14.13.5499.
DNA from the "non-transcribed spacer" (NTS) of two wheat ribosomal RNA gene (rDNA) clones was sequenced. The regions flanking the internal subrepeat arrays are highly conserved between the two clones; the nucleotide sequence differ by less than one-half percent. In contrast, the consensus sequences of the subrepeats in the two arrays differ by three percent. Mutations unique to each array, yet found in more than one subrepeat of the array, are preferentially found in adjacent and alternate subrepeats. The similarity of the DNA sequences of the flanking regions is consistent with a model of homogenization among rDNA gene units by intergenic conversion. We propose that a different mechanism, preferential conversion between neighboring subrepeats, is largely responsible for the homogenization of subrepeats within an array.
对两个小麦核糖体RNA基因（rDNA）克隆的“非转录间隔区”（NTS）的DNA进行了测序。两个克隆中内部亚重复序列阵列两侧的区域高度保守；核苷酸序列差异小于0.5%。相比之下，两个阵列中亚重复序列的共有序列差异为3%。每个阵列特有的突变，且在该阵列的多个亚重复序列中都能找到，优先出现在相邻和交替的亚重复序列中。侧翼区域DNA序列的相似性与通过基因间转换实现rDNA基因单位间同质化的模型一致。我们提出，一种不同的机制，即相邻亚重复序列之间的优先转换，在很大程度上导致了阵列内亚重复序列的同质化。
