Department of Plant Sciences, University of California, Mail Stop 1, One Shields Avenue, Davis, CA 95616-8780, USA.
Funct Integr Genomics. 2010 May;10(2):293-306. doi: 10.1007/s10142-009-0146-7. Epub 2009 Oct 23.
The earliness per se gene Eps-A ( m ) 1 from diploid wheat Triticum monococcum affects heading time, spike development, and spikelet number. In this study, the Eps1 orthologous regions from rice, Aegilops tauschii, and Brachypodium distachyon were compared as part of current efforts to clone this gene. A single Brachypodium BAC clone spanned the Eps-A ( m ) 1 region, but a gap was detected in the A. tauschii physical map. Sequencing of the Brachypodium and A. tauschii BAC clones revealed three genes shared by the three species, which showed higher identity between wheat and Brachypodium than between them and rice. However, most of the structural changes were detected in the wheat lineage. These included an inversion encompassing the wg241-VatpC region and the presence of six unique genes. In contrast, only one unique gene (and one pseudogene) was found in Brachypodium and none in rice. Three genes were present in both Brachypodium and wheat but were absent in rice. Two of these genes, Mot1 and FtsH4, were completely linked to the earliness per se phenotype in the T. monococcum high-density genetic map and are candidates for Eps-A ( m ) 1. Both genes were expressed in apices and developing spikes, as expected for Eps-A ( m ) 1 candidates. The predicted MOT1 protein showed amino acid differences between the parental T. monococcum lines, but its effect is difficult to predict. Future steps to clone the Eps-A ( m ) 1 gene include the generation of mot1 and ftsh4 mutants and the completion of the T. monococcum physical map to test for the presence of additional candidate genes.
Eps-A(m)1 早熟基因本身来自二倍体小麦普通小麦，影响抽穗期、穗发育和小穗数。在这项研究中，水稻、节节麦和短柄草的 Eps1 直系同源区被比较，作为目前克隆该基因的努力的一部分。一个单一的短柄草 BAC 克隆跨越了 Eps-A(m)1 区域，但在节节麦物理图谱中检测到一个缺口。对短柄草和节节麦 BAC 克隆的测序揭示了三个在三个物种中共享的基因，它们在小麦和短柄草之间的同一性高于它们与水稻之间的同一性。然而，大多数结构变化是在小麦谱系中检测到的。这些包括一个包含 wg241-VatpC 区域的倒位和六个独特基因的存在。相比之下，在短柄草和水稻中只发现了一个独特的基因（和一个假基因）。在短柄草和小麦中都存在三个基因，但在水稻中不存在。其中两个基因，Mot1 和 FtsH4，完全与 T. monococcum 高密度遗传图谱中的早熟表型相关联，是 Eps-A(m)1 的候选基因。这两个基因都在顶端和发育中的穗中表达，这与 Eps-A(m)1 候选基因的预期一致。预测的 MOT1 蛋白在亲本 T. monococcum 系之间显示出氨基酸差异，但它的影响很难预测。克隆 Eps-A(m)1 基因的未来步骤包括 mot1 和 ftsh4 突变体的生成以及 T. monococcum 物理图谱的完成，以测试是否存在其他候选基因。
