Hancock J M, Dover G A
Department of Genetics, University of Cambridge, UK.
Nucleic Acids Res. 1990 Oct 25;18(20):5949-54. doi: 10.1093/nar/18.20.5949.
The distribution patterns of shared short repetitive motifs in the expansion segments of the large subunit rRNA genes of different species show that these segments are coevolving as a set and that in two examined vertebrate species the RNA secondary structures are conserved as a consequence of runs of motifs in one region being compensated by complementary motifs in another. These unusual processes, involving replication-slippage, have implications for the evolution of ribosomal RNA and for the use of the rDNA multigene family as a 'molecular clock' for assessing relationships between species.
不同物种的大亚基核糖体RNA基因扩增片段中共享短重复基序的分布模式表明,这些片段作为一个整体共同进化,并且在两个被研究的脊椎动物物种中,RNA二级结构得以保守,这是由于一个区域的基序串被另一个区域的互补基序所补偿。这些涉及复制滑移的异常过程,对核糖体RNA的进化以及将rDNA多基因家族用作评估物种间关系的“分子时钟”具有启示意义。