Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Martonvásár, Hungary.
PLoS One. 2013 Aug 5;8(8):e70844. doi: 10.1371/journal.pone.0070844. Print 2013.
Diploid Aegilops umbellulata and Ae. comosa and their natural allotetraploid hybrids Ae. biuncialis and Ae. geniculata are important wild gene sources for wheat. With the aim of assisting in alien gene transfer, this study provides gene-based conserved orthologous set (COS) markers for the U and M genome chromosomes. Out of the 140 markers tested on a series of wheat-Aegilops chromosome introgression lines and flow-sorted subgenomic chromosome fractions, 100 were assigned to Aegilops chromosomes and six and seven duplications were identified in the U and M genomes, respectively. The marker-specific EST sequences were BLAST-ed to Brachypodium and rice genomic sequences to investigate macrosyntenic relationships between the U and M genomes of Aegilops, wheat and the model species. Five syntenic regions of Brachypodium identified genome rearrangements differentiating the U genome from the M genome and from the D genome of wheat. All of them seem to have evolved at the diploid level and to have been modified differentially in the polyploid species Ae. biuncialis and Ae. geniculata. A certain level of wheat-Aegilops homology was detected for group 1, 2, 3 and 5 chromosomes, while a clearly rearranged structure was showed for the group 4, 6 and 7 Aegilops chromosomes relative to wheat. The conserved orthologous set markers assigned to Aegilops chromosomes promise to accelerate gene introgression by facilitating the identification of alien chromatin. The syntenic relationships between the Aegilops species, wheat and model species will facilitate the targeted development of new markers specific for U and M genomic regions and will contribute to the understanding of molecular processes related to allopolyploidization.
二倍体节节麦和长穗偃麦草及其天然异源四倍体杂种冰草和粗山羊草是小麦重要的野生基因源。本研究旨在辅助外源基因转移，为 U 和 M 基因组染色体提供基于基因的保守直系同源物集合（COS）标记。在一系列小麦-节节麦染色体渗入系和流式分选亚基因组染色体片段上测试了 140 个标记，其中 100 个标记被分配到节节麦染色体上，在 U 和 M 基因组中分别鉴定到 6 个和 7 个加倍。标记特异性 EST 序列与拟南芥和水稻基因组序列进行 BLAST 分析，以研究节节麦、小麦和模式物种 U 和 M 基因组之间的宏基因组关系。在拟南芥基因组中鉴定到 5 个与 U 基因组和 M 基因组以及小麦 D 基因组区分开的共线性区域的基因组重排。所有这些似乎都是在二倍体水平进化的，并且在异源四倍体冰草和粗山羊草中发生了不同的修饰。在第 1、2、3 和 5 染色体上检测到了一定程度的小麦-节节麦同源性，而在第 4、6 和 7 条节节麦染色体上相对于小麦显示出明显的重排结构。分配到节节麦染色体的保守直系同源物集合标记有望通过促进鉴定外源染色质来加速基因渗入。节节麦种、小麦和模式种之间的共线性关系将有助于针对 U 和 M 基因组区域开发新的特异性标记，并有助于理解与异源多倍化相关的分子过程。
