Effect of colchicine and telocentric chromosome conformation on centromere and telomere dynamics at meiotic prophase I in wheat-rye additions
Effect of colchicine and telocentric chromosome conformation on centromere and telomere dynamics at meiotic prophase I in wheat-rye additions
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DOI：
10.1007/s10577-006-1117-7
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发表时间：
2007-02-01
影响因子：
2.6
通讯作者：
Naranjo, Tomas
中科院分区：
文献类型：
--
作者：
Corredor, Eduardo;Naranjo, Tomas
花束中端粒的联合和着丝粒区域的聚集被认为参与了同源伙伴的搜索和识别。我们分析了这些结构在小麦-黑麦附加系减数分裂染色体配对中的作用，方法是应用秋水仙素干扰突触前端粒运动，并将着丝粒位置从亚中部着丝粒改变为端着丝粒，以研究着丝粒效应。通过荧光原位杂交鉴定了黑麦染色体、小麦和黑麦着丝粒以及端粒。从黑麦着丝粒的行为推断，着丝粒成对或在更复杂的结构中的突触前联系主要涉及非同源染色体。而着丝粒结合不受秋水仙碱的影响，秋水仙碱抑制花束的形成，从而导致同源突触失败。黑麦端粒着丝粒的同源着丝粒早于黑麦亚中部着丝粒染色体的着丝粒，表明在花束形成过程中，端粒着丝粒向端粒极的迁移促进了它们的联系。处于减数分裂前间期的同源染色体可以相互识别，并在合子线处启动联会。然而，端粒聚合是需要的，以使大多数同源对聚集在一起，这些对通常在减数分裂前核中占据不同的区域。
Association of telomeres in a bouquet and clustering of centromere regions have been proposed to be involved in the search and recognition of homologous partners. We have analysed the role of these structures in meiotic chromosome pairing in wheat-rye addition lines by applying colchicine for disturbing presynaptic telomere movements and by modifying the centromere position from submetacentric to telocentric for studying centromere effects. Rye chromosomes, wheat and rye centromeres, and telomeres were identified by fluorescence in-situ hybridization. Presynaptic association of centromeres in pairs or in more complex structures involved mainly non-homologous chromosomes as deduced from the behaviour of rye centromeres. While centromere association was not affected by colchicine, colchicine inhibited bouquet formation, which caused failure of homologous synapsis. Homologous centromeres of rye telocentrics associated earlier than those of rye submetacentric chromosomes, indicating that migration of the telocentrics' centromeres to the telomere pole during bouquet formation facilitated their association. Homologous chromosomes associated in premeiotic interphase can recognize each other and initiate synapsis at zygotene. However, telomere convergence is needed for bringing together the majority of homologous pairs that normally occupy separate territories in premeiotic nuclei.