A cytological approach to studying meiotic recombination and chromosome dynamics in Arabidopsis thaliana male meiocytes in three dimensions
A cytological approach to studying meiotic recombination and chromosome dynamics in Arabidopsis thaliana male meiocytes in three dimensions
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DOI：
10.1111/tpj.13942
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发表时间：
2018-07-01
期刊：
影响因子：
7.2
通讯作者：
Christophorou, Nicolas
中科院分区：
文献类型：
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作者：
Hurel, Aurelie;Phillips, Dylan;Christophorou, Nicolas
在减数分裂前期，染色体发生剧烈的构象变化，伴随着染色体凝聚、配对和同源物之间的重组。这些变化包括端粒锚定在核膜上，并聚集成束。在植物中，这些事件已经在具有大基因组的物种的完整减数细胞中进行了研究和说明。拟南芥（Arabidopsis thaliana）是一个很好的遗传模型，其中控制突触和同源物之间重组的主要分子途径已经被发现。然而，染色体动力学的研究受到当前细胞学方法的阻碍，这些方法破坏了细胞核的三维（3D）结构。在这里，我们建立了一个协议，以保存拟南拟南草减数细胞的三维结构。我们发现这种技术与多种标记结构和重组蛋白的抗体兼容，并且能够突出核周围聚集的突触起始中心的存在。利用荧光原位杂交技术，我们还研究了染色体在减数分裂前G(2)期和前期I期的行为，揭示了在假丝楠雄性减数分裂期间存在端粒束。此外，我们发现花束中的端粒数量及其体积变化很大，从而揭示了减数分裂前期端粒行为的复杂性。最后，通过标记单个染色体亚端粒区域的探针，我们揭示了染色体末端的差异定位行为。我们的方案为研究拟南芥减数细胞的染色体动力学开辟了新的研究领域。
During meiotic prophase I chromosomes undergo dramatic conformational changes that accompany chromosome condensation, pairing and recombination between homologs. These changes include the anchoring of telomeres to the nuclear envelope and their clustering to form a bouquet. In plants, these events have been studied and illustrated in intact meiocytes of species with large genomes. Arabidopsis thaliana is an excellent genetic model in which major molecular pathways that control synapsis and recombination between homologs have been uncovered. Yet the study of chromosome dynamics is hampered by current cytological methods that disrupt the three-dimensional (3D) architecture of the nucleus. Here we set up a protocol to preserve the 3D configuration of A. thaliana meiocytes. We showed that this technique is compatible with the use of a variety of antibodies that label structural and recombination proteins and were able to highlight the presence of clustered synapsis initiation centers at the nuclear periphery. By using fluorescence insitu hybridization we also studied the behavior of chromosomes during pre-meiotic G(2) and prophase I, revealing the existence of a telomere bouquet during A. thaliana male meiosis. In addition we showed that the number of telomeres in a bouquet and its volume vary greatly, thus revealing the complexity of telomere behavior during meiotic prophase I. Finally, by using probes that label subtelomeric regions of individual chromosomes, we revealed differential localization behaviors of chromosome ends. Our protocol opens new areas of research for investigating chromosome dynamics in A. thaliana meiocytes.