Next-generation sequencing and syntenic integration of flow-sorted arms of wheat chromosome 4A exposes the chromosome structure and gene content
Next-generation sequencing and syntenic integration of flow-sorted arms of wheat chromosome 4A exposes the chromosome structure and gene content
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DOI：
10.1111/j.1365-313x.2011.04808.x
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发表时间：
2012-02-01
期刊：
影响因子：
7.2
通讯作者：
Mayer, Klaus F. X.
中科院分区：
文献类型：
--
作者：
Hernandez, Pilar;Martis, Mihaela;Mayer, Klaus F. X.
小麦是世界上第三大人类营养作物。高分辨率遗传和物理图谱的可获得性以及最终的完整基因组序列为培育改良品种以应对不断变化的全球气候条件下日益增长的粮食需求带来了巨大的希望。然而，面包小麦(Triticum Aestivum)基因组的大小(约17 GB/1C)以及由于其六倍体状态导致的基因序列的三倍体阻碍了这一重要作物物种的基因组测序。在这里，我们描述了使用有丝分裂染色体流动分选来分别纯化并对一对共同形成4A染色体(856Mb/1C)的小麦的端粒染色体进行鸟枪测序。这种大大减少的模板的分离和由此产生的避免了序列重复的问题，结合基于同步性的与其他牧草基因组的比较，促进了4A染色体基因图谱的构建，包括其总基因含量的85%，并使4A染色体上的各种易位和反转断裂点得以精确定位，这些断裂点将其与A基因组二倍体供体的祖先染色体区分开来。染色体4A的基因图谱，以及新出现的同源小麦染色体组4、5和7的序列，代表着独特的资源，将使我们能够对同源染色体和同源染色体区域之间的进化动力学获得新的见解。
Wheat is the third most important crop for human nutrition in the world. The availability of high-resolution genetic and physical maps and ultimately a complete genome sequence holds great promise for breeding improved varieties to cope with increasing food demand under the conditions of changing global climate. However, the large size of the bread wheat (Triticum aestivum) genome (approximately 17 Gb/1C) and the triplication of genic sequence resulting from its hexaploid status have impeded genome sequencing of this important crop species. Here we describe the use of mitotic chromosome flow sorting to separately purify and then shotgun-sequence a pair of telocentric chromosomes that together form chromosome 4A (856 Mb/1C) of wheat. The isolation of this much reduced template and the consequent avoidance of the problem of sequence duplication, in conjunction with synteny-based comparisons with other grass genomes, have facilitated construction of an ordered gene map of chromosome 4A, embracing >= 85% of its total gene content, and have enabled precise localization of the various translocation and inversion breakpoints on chromosome 4A that differentiate it from its progenitor chromosome in the A genome diploid donor. The gene map of chromosome 4A, together with the emerging sequences of homoeologous wheat chromosome groups 4, 5 and 7, represent unique resources that will allow us to obtain new insights into the evolutionary dynamics between homoeologous chromosomes and syntenic chromosomal regions.