PNAS
Abstract
The organization of microtubules into a bipolar spindle is essential for chromosome segregation. Both centrosome and chromatin-dependent spindle assembly mechanisms are well studied in mouse, Drosophila melanogaster, and Xenopus oocytes; however, the mechanism of bipolar spindle assembly in plant meiosis remains elusive. According to our observations of microtubule assembly in Oryza sativa, Zea mays, Arabidopsis thaliana, and Solanum lycopersicum, we propose that a key step of plant bipolar spindle assembly is the correction of the multipolar spindle into a bipolar spindle at metaphase I. The multipolar spindles failed to transition into bipolar ones in OsmtopVIB with the defect in double-strand break (DSB) formation. However, bipolar spindles were normally assembled in several other mutants lacking DSB formation, such as Osspo11-1, pair2, and crc1, indicating that bipolar spindle assembly is independent of DSB formation. We further revealed that the mono-orientation of sister kinetochores was prevalent in OsmtopVIB, whereas biorientation of sister kinetochores was frequently observed in Osspo11-1, pair2, and crc1. In addition, mutations of the cohesion subunit OsREC8 resulted in biorientation of sister kinetochores as well as bipolar spindles even in the background of OsmtopVIB. Therefore, we propose that biorientation of the kinetochore is required for bipolar spindle assembly in the absence of homologous recombination.
| 论文编号: | DOI:10.1073/pnas.1821315116 |
| 论文题目: | OsMTOPVIB is Required for Meiotic Bipolar Spindle Assembly |
| 英文论文题目: | OsMTOPVIB is Required for Meiotic Bipolar Spindle Assembly |
| 第一作者: | Zhihui Xue, Changzhen Liu, Wenqing Shi, Yongjie Miao, Yi Shen, Ding Tang, Yafei Li, Aiqing You, Yunyuan Xu, Kang Chong, and Zhukuan Cheng |
| 英文第一作者: | Zhihui Xue, Changzhen Liu, Wenqing Shi, Yongjie Miao, Yi Shen, Ding Tang, Yafei Li, Aiqing You, Yunyuan Xu, Kang Chong, and Zhukuan Cheng |
| 联系作者: | |
| 英文联系作者: | |
| 外单位作者单位: | |
| 英文外单位作者单位: | |
| 发表年度: | 2019-07-25 |
| 卷: | |
| 期: | |
| 页码: | |
| 摘要: | The organization of microtubules into a bipolar spindle is essential for chromosome segregation. Both centrosome and chromatin-dependent spindle assembly mechanisms are well studied in mouse, Drosophila melanogaster, and Xenopus oocytes; however, the mechanism of bipolar spindle assembly in plant meiosis remains elusive. According to our observations of microtubule assembly in Oryza sativa, Zea mays, Arabidopsis thaliana, and Solanum lycopersicum, we propose that a key step of plant bipolar spindle assembly is the correction of the multipolar spindle into a bipolar spindle at metaphase I. The multipolar spindles failed to transition into bipolar ones in OsmtopVIB with the defect in double-strand break (DSB) formation. However, bipolar spindles were normally assembled in several other mutants lacking DSB formation, such as Osspo11-1, pair2, and crc1, indicating that bipolar spindle assembly is independent of DSB formation. We further revealed that the mono-orientation of sister kinetochores was prevalent in OsmtopVIB, whereas biorientation of sister kinetochores was frequently observed in Osspo11-1, pair2, and crc1. In addition, mutations of the cohesion subunit OsREC8 resulted in biorientation of sister kinetochores as well as bipolar spindles even in the background of OsmtopVIB. Therefore, we propose that biorientation of the kinetochore is required for bipolar spindle assembly in the absence of homologous recombination. |
| 英文摘要: | The organization of microtubules into a bipolar spindle is essential for chromosome segregation. Both centrosome and chromatin-dependent spindle assembly mechanisms are well studied in mouse, Drosophila melanogaster, and Xenopus oocytes; however, the mechanism of bipolar spindle assembly in plant meiosis remains elusive. According to our observations of microtubule assembly in Oryza sativa, Zea mays, Arabidopsis thaliana, and Solanum lycopersicum, we propose that a key step of plant bipolar spindle assembly is the correction of the multipolar spindle into a bipolar spindle at metaphase I. The multipolar spindles failed to transition into bipolar ones in OsmtopVIB with the defect in double-strand break (DSB) formation. However, bipolar spindles were normally assembled in several other mutants lacking DSB formation, such as Osspo11-1, pair2, and crc1, indicating that bipolar spindle assembly is independent of DSB formation. We further revealed that the mono-orientation of sister kinetochores was prevalent in OsmtopVIB, whereas biorientation of sister kinetochores was frequently observed in Osspo11-1, pair2, and crc1. In addition, mutations of the cohesion subunit OsREC8 resulted in biorientation of sister kinetochores as well as bipolar spindles even in the background of OsmtopVIB. Therefore, we propose that biorientation of the kinetochore is required for bipolar spindle assembly in the absence of homologous recombination. |
| 刊物名称: | PNAS |
| 英文刊物名称: | PNAS |
| 论文全文: | |
| 英文论文全文: | |
| 全文链接: | |
| 其它备注: | Zhihui Xue, Changzhen Liu, Wenqing Shi, Yongjie Miao, Yi Shen, Ding Tang, Yafei Li, Aiqing You, Yunyuan Xu, Kang Chong, and Zhukuan Cheng. OsMTOPVIB is Required for Meiotic Bipolar Spindle Assembly. PNAS. DOI:10.1073/pnas.1821315116 |
| 英文其它备注: | |
| 学科: | |
| 英文学科: | |
| 影响因子: | |
| 第一作者所在部门: | |
| 英文第一作者所在部门: | |
| 论文出处: | |
| 英文论文出处: | |
| 论文类别: | |
| 英文论文类别: | |
| 参与作者: | |
| 英文参与作者: |
