State Key Laboratory of Plant Breeding and Genetics, Sichuan Agriculture University, Ya'an, Sichuan 625014, China.
Genome. 2011 Apr;54(4):285-300. doi: 10.1139/g10-118.
We present the first characterization of 360 sequences in six species of the genus Secale of both cultivated and wild accessions. These include four distinct kinds of dispersed repetitive DNA sequences named pSc20H, pSc119.1, pSaO5(411), and pSaD15(940) belonging to the Revolver family. During the evolution of the genus Secale from wild to cultivated accessions, the pSaO5(411)-like sequences became shorter mainly because of the deletion of a trinucleotide tandem repeating unit, the pSc20H-like sequences displayed apparent homogenization in cultivated rye, and the second intron of Revolver became longer. In addition, the pSc20H-, pSc119.1-, and pSaO5(411)-like sequences cloned from wild rye and cultivated rye could be divided into two large clades. No single case of the four kinds of repetitive elements has been inherited by each Secale accession from a lone ancestor. It is reasonable to consider the vertical transmission of the four repetitive elements during the evolution of the genus Secale. The pSc20H- and pSaO5(411)-like sequences showed evolutionary elimination at specific chromosomal locations from wild species to cultivated species. These cases imply that different repetitive DNA sequences have played different roles in the chromosome development and genomic evolution of rye. The present study adds important information to the investigations dealing with characterization of dispersed repetitive elements in wild and cultivated rye.
我们首次对六个黑麦属物种（包括四个栽培种和两个野生种）的 360 个序列进行了特征描述。这六个物种包含了四种不同的分散重复 DNA 序列，分别命名为 pSc20H、pSc119.1、pSaO5(411)和 pSaD15(940)，它们都属于 Revolver 家族。在黑麦属从野生种到栽培种的进化过程中，pSaO5(411)样序列主要由于三核苷酸串联重复单元的缺失而变短，pSc20H 样序列在栽培黑麦中表现出明显的同质化，Revolver 的第二个内含子变长。此外，从野生黑麦和栽培黑麦克隆的 pSc20H、pSc119.1 和 pSaO5(411)样序列可以分为两个大的分支。这四种重复元件没有一个在每个黑麦种系中都是由一个单独的祖先遗传而来。可以合理地认为这四种重复元件在黑麦属的进化过程中是通过垂直传递的。pSc20H 和 pSaO5(411)样序列在从野生种到栽培种的进化过程中，在特定的染色体位置上发生了进化性消除。这些情况表明，不同的重复 DNA 序列在黑麦的染色体发育和基因组进化中发挥了不同的作用。本研究为研究野生和栽培黑麦中分散重复元件的特征提供了重要信息。
