Delimitation of wheat ph1b deletion and development of ph1b-specific DNA markers
Delimitation of wheat ph1b deletion and development of ph1b-specific DNA markers
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DOI：
10.1007/s00122-018-3207-2
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发表时间：
2019-01-01
影响因子：
5.4
通讯作者：
Cai, Xiwen
中科院分区：
文献类型：
--
作者：
Gyawali, Yadav;Zhang, Wei;Cai, Xiwen
我们检测了小麦ph1b突变体的缺失断点和缺失的实际大小。此外，我们开发了ph1b缺失特异性标记，用于ph1b介导的基因渗入和基因组研究。摘要Ph1（配对同源）位点被认为是小麦异源多倍体基因组二倍体减数分裂行为的主要遗传系统。它是多倍体小麦减数分裂同源配对和重组的防御系统。“中国春”六倍体小麦5B染色体长臂上含有Ph1的基因组区域的大量缺失导致ph1b突变体的产生，该突变体已被广泛用于诱导野草基因向小麦基因渗透的减数分裂同源重组。但是，删除的断点和物理大小仍然未确定。在本研究中，我们首先通过高通量小麦90K SNP测定将ph1b缺失锚定在5BL上，然后通过染色体行走将缺失区域划分到60,014,523bp的基因组区域。DNA标记和序列分析检测了ph1b缺失和缺失连接的远端和近端断点（DB和PB）的核苷酸位置。这将有助于了解小麦中含有Ph1位点的基因组区域。此外，我们还开发了针对ph1b缺失的用户友好型DNA标记。这些新的ph1b缺失特异性标记将显著提高ph1b突变体在小麦及其近缘植物减数分裂同源重组基因渗入和基因组研究中的有效性。
Key messageWe detected the deletion breakpoints of wheat ph1b mutant and the actual size of the deletion. Also, we developed ph1b deletion-specific markers useful for ph1b-mediated gene introgression and genome studies.AbstractThe Ph1 (pairing homoeologous) locus has been considered a major genetic system for the diploidized meiotic behavior of the allopolyploid genome in wheat. It functions as a defense system against meiotic homoeologous pairing and recombination in polyploid wheat. A large deletion of the genomic region harboring Ph1 on the long arm of chromosome 5B (5BL) led to the ph1b mutant in hexaploid wheat Chinese Spring,' which has been widely used to induce meiotic homoeologous recombination for gene introgression from wild grasses into wheat. However, the breakpoints and physical size of the deletion remain undetermined. In the present study, we first anchored the ph1b deletion on 5BL by the high-throughput wheat 90K SNP assay and then delimited the deletion to a genomic region of 60,014,523bp by chromosome walking. DNA marker and sequence analyses detected the nucleotide positions of the distal and proximal breakpoints (DB and PB) of the ph1b deletion and the deletion junction as well. This will facilitate understanding of the genomic region harboring the Ph1 locus in wheat. In addition, we developed user-friendly DNA markers specific for the ph1b deletion. These new ph1b deletion-specific markers will dramatically improve the efficacy of the ph1b mutant in the meiotic homoeologous recombination-based gene introgression and genome studies in wheat and its relatives.