State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China.
College of Agronomy, Sichuan Agricultural University, Chengdu, 611130, China.
BMC Genomics. 2023 Aug 11;24(1):455. doi: 10.1186/s12864-023-09525-9.
The 1RS arm of wheat-rye 1BL.1RS translocations contains several subtelomeric tandem repeat families. To study the effect of the difference in the composition of these tandem repeats on the meiotic recombination of 1RS arms can help to enrich the genetic diversity of 1BL.1RS translocation chromosomes.
Five wheat-rye 1BL.1RS translocation cultivars/lines were used to build two cross combinations including group 1 (20T401 × Zhou 8425B, 20T401 × Lovrin 10 and 20T401 × Chuannong 17) and group 2 (20T360-2 × Zhou 8425B, 20T360-2 × Lovrin 10 and 20T360-2 × Chuannong 17). Oligonucleotide (oligo) probes Oligo-s120.3, Oligo-TR72, and Oligo-119.2-2 produced the same signal pattern on the 1RS arms in lines 20T401 and 20T360-2, and another signal pattern in the three cultivars Zhou 8425B, Lovrin 10 and Chuannong 17. The Oligo-pSc200 signal disappeared from the 1RS arms of the line 20T401, and the signal intensity of this probe on the 1RS arms of the line 20T360-2 was weaker than that of the three cultivars. The five cultivars/lines had the same signal pattern of the probe Oligo-pSc250. The recombination rate of 1RS arms in group 1 was significantly lower than that in group 2. In the progenies from group 1, unequal meiotic recombination in the subtelomeric pSc119.2 and pSc250 tandem repeat regions, and a 1BL.1RS with inversion of 1RS segment between the pSc200 and the nucleolar organizer region were found.
This study provides a visual tool to detect the meiotic recombination of 1RS arms. The meiotic recombination rate of 1RS arms was affected by the variation of pSc200 tandem repeat, indicating the similar composition of subtelomeric tandem repeats on these arms could increase their recombination rate. These results indicate that the 1RS subtelomeric structure will affect its recombination, and thus the localization of genes on 1RS by means of meiotic recombination might also be affected.
小麦-黑麦 1BL.1RS 易位的 1RS 臂含有几个端粒串联重复家族。研究这些串联重复组成的差异对 1RS 臂减数分裂重组的影响有助于丰富 1BL.1RS 易位染色体的遗传多样性。
使用五个小麦-黑麦 1BL.1RS 易位品种/系构建了两个杂交组合，包括第 1 组（20T401×Zhou 8425B、20T401×Lovrin 10 和 20T401×Chuan-nong 17）和第 2 组（20T360-2×Zhou 8425B、20T360-2×Lovrin 10 和 20T360-2×Chuan-nong 17）。寡核苷酸（oligo）探针 Oligo-s120.3、Oligo-TR72 和 Oligo-119.2-2 在 20T401 和 20T360-2 系的 1RS 臂上产生相同的信号模式，而在三个品种 Zhou 8425B、Lovrin 10 和 Chuan-nong 17 上则产生另一种信号模式。寡核苷酸探针 Oligo-pSc200 的信号从 20T401 系的 1RS 臂中消失，而该探针在 20T360-2 系的 1RS 臂上的信号强度弱于三个品种。五个品种/系的寡核苷酸探针 Oligo-pSc250 具有相同的信号模式。第 1 组的 1RS 臂重组率明显低于第 2 组。在第 1 组的后代中，发现端粒 pSc119.2 和 pSc250 串联重复区的不等减数分裂重组，以及在 pSc200 和核仁组织者区之间的 1RS 段倒位的 1BL.1RS。
本研究提供了一种检测 1RS 臂减数分裂重组的可视化工具。1RS 臂的减数分裂重组率受 pSc200 串联重复变异的影响，表明这些臂上端粒串联重复的相似组成可以增加它们的重组率。这些结果表明 1RS 端粒结构会影响其重组，从而通过减数分裂重组对 1RS 上基因的定位也可能受到影响。
