Department of Crop and Soil Sciences, Washington State University, Pullman, WA, USA.
USDA-ARS Western Wheat Quality Laboratory, Pullman, WA, USA.
Theor Appl Genet. 2017 May;130(5):891-902. doi: 10.1007/s00122-017-2858-8. Epub 2017 Mar 13.
Recombination at the Glu-3 loci was identified, and strong genetic linkage was observed only between the amplicons representing i-type and s-type genes located, respectively, at the Glu-A3 and Glu-B3 loci. The low-molecular weight glutenin subunits (LMW-GSs) are one of the major components of wheat seed storage proteins and play a critical role in the determination of wheat end-use quality. The genes encoding this class of proteins are located at the orthologous Glu-3 loci (Glu-A3, Glu-B3, and Glu-D3). Due to the complexity of these chromosomal regions and the high sequence similarity between different LMW-GS genes, their organization and recombination characteristics are still incompletely understood. This study examined intralocus recombination at the Glu-3 loci in two recombinant inbred line (RIL) and one doubled haploid (DH) population, all segregating for the Glu-A3, Glu-B3, and Glu-D3 loci. The analysis was conducted using a gene marker system that consists of the amplification of the complete set of the LMW-GS genes and their visualization by capillary electrophoresis. Recombinant marker haplotypes were detected in all three populations with different recombination rates depending on the locus and the population. No recombination was observed between the amplicons representing i-type and s-type LMW-GS genes located, respectively, at the Glu-A3 and Glu-B3 loci, indicating tight linkage between these genes. Results of this study contribute to better understanding the genetic linkage and recombination between different LMW-GS genes, the structure of the Glu-3 loci, and the development of more specific molecular markers that better represent the genetic diversity of these loci. In this way, a more precise analysis of the contribution of various LMW-GSs to end-use quality of wheat may be achieved.
鉴定到 Glu-3 基因座的重组，并且仅观察到分别位于 Glu-A3 和 Glu-B3 基因座的 i 型和 s 型基因代表扩增子之间的强遗传连锁。低分子量谷蛋白亚基（LMW-GS）是小麦种子贮藏蛋白的主要成分之一，在决定小麦的最终用途品质方面起着关键作用。编码这类蛋白质的基因位于同源的 Glu-3 基因座（Glu-A3、Glu-B3 和 Glu-D3）上。由于这些染色体区域的复杂性和不同 LMW-GS 基因之间的高度序列相似性，它们的组织和重组特征仍不完全清楚。本研究在两个重组自交系（RIL）和一个加倍单倍体（DH）群体中检查了 Glu-3 基因座的基因内重组，所有这些群体都分离出 Glu-A3、Glu-B3 和 Glu-D3 基因座。该分析使用基因标记系统进行，该系统由扩增完整的 LMW-GS 基因集及其通过毛细管电泳的可视化组成。在所有三个群体中都检测到重组标记单倍型，其重组率取决于基因座和群体。在分别位于 Glu-A3 和 Glu-B3 基因座的 i 型和 s 型 LMW-GS 基因代表的扩增子之间未观察到重组，表明这些基因之间紧密连锁。本研究的结果有助于更好地理解不同 LMW-GS 基因之间的遗传连锁和重组、Glu-3 基因座的结构以及开发更能代表这些基因座遗传多样性的更具体的分子标记。通过这种方式，可以更精确地分析各种 LMW-GS 对小麦最终用途品质的贡献。
