PDF(Pubmed)
Abstract：
Meiotic rapid prophase chromosome movements (RPMs) require connections between the chromosomes and the cytoskeleton, involving SUN (Sad1/UNC-84)-domain-containing proteins at the inner nuclear envelope (NE). RPMs remain significantly understudied in plants, with respect to their importance in the regulation of meiosis. Here, we demonstrate that Arabidopsis thaliana meiotic centromeres undergo rapid (up to 500 nm/s) and uncoordinated movements during the zygotene and pachytene stages. These centromere movements are not affected by altered chromosome organization and recombination but are abolished in the double mutant sun1 sun2. We also document the changes in chromosome dynamics and nucleus organization during the transition from leptotene to zygotene, including telomere attachment to SUN-enriched NE domains, bouquet formation, and nucleolus displacement, all of which were defective in sun1 sun2. These results establish A. thaliana as a model species for studying the functional implications of meiotic RPMs and demonstrate the mechanistic conservation of telomere-led RPMs in plants.
摘要：
减数分裂的快速前期染色体运动（RPM）需要染色体和细胞骨架之间的连接，涉及内核被膜（NE）的含SUN（Sad1/UNC-84）域的蛋白质。RPM在植物中仍未得到充分研究，关于它们在调节减数分裂中的重要性。这里,我们证明，拟南芥减数分裂着丝粒在合子和粗线质阶段经历快速（高达500nm/s）和不协调的运动。这些着丝粒运动不受染色体组织和重组改变的影响，但在双突变体sun1sun2中被废除。我们还记录了从瘦素到受精卵过渡期间染色体动力学和细胞核组织的变化，包括端粒附着到富含太阳的NE域，花束形成，和核仁位移，所有这些在sun1sun2中都有缺陷。这些结果将拟南芥确立为研究减数分裂RPM的功能意义的模型物种，并证明了端粒主导的RPM在植物中的机制保守性。
