Nuclear organization in crucifer genomes: nucleolus-associated telomere clustering is not a universal interphase configuration in Brassicaceae.
Nuclear organization in crucifer genomes: nucleolus-associated telomere clustering is not a universal interphase configuration in Brassicaceae.
复制标题
十字花科植物基因组中的核组织：核仁相关端粒聚类不是十字花科中通用的间期配置。
DOI：
10.1111/tpj.15459
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
M. Lysak
中科院分区：
文献类型：
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作者：
Wenbo Shan;Michaela Kubová;T. Mandáková;M. Lysak
拟南芥已经成为间期核组织表现出独特特征的主要植物研究模型，其中包括核仁相关的端粒聚集性。染色中心(CC)环模型，或玫瑰花样构型，描述了拟南芥的核内染色质组织为锚定在外周定位的染色质中心和含有与核仁相关的端粒的兆基长环。为了研究CC环组织是否在十字花科植物中普遍存在，用荧光原位杂交技术分析了7个二倍体物种(2n=10-16)的着丝粒、端粒和核仁的核分布，这些二倍体物种代表了主要的十字花科分支，基因组大小变化高达26倍(160Mb-4260Mb)。核仁相关的端粒聚集在拟南芥(157Mb)中被证实，并被新鉴定为其他具有小基因组(215-381Mb)的物种的主要核表型。在大基因组物种(2-611-4和264Mb)中，着丝粒和端粒要么呈Rabl样构型，要么分散分布在核内部；端粒很少与核仁联系。在拟南星(381 Mb)和侧柏(2~611 Mb)中，花药和茎组织中分别观察到偏离主要核表型的组织特异性模式。来自不同亚门的小基因组物种中的玫瑰花状构型，包括与核仁相关的端粒聚集，表明决定间期核组织的是基因组性质，而不是系统发育位置。我们的数据表明，核基因组大小、平均染色体大小和纵向染色体区划程度影响着十字花科植物基因组中的间期染色体组织。
Arabidopsis thaliana (arabidopsis) has become a major plant research model where interphase nuclear organization exhibits unique features, including nucleolus-associated telomere clustering. The chromocenter (CC)-loop model, or rosette-like configuration, describes intranuclear chromatin organization in arabidopsis as megabase-long loops anchored in, and emanating from, peripherally positioned chromocenters, and those containing telomeres associate with the nucleolus. To investigate whether the CC-loop organization is universal across the mustard family (crucifers), the nuclear distributions of centromeres, telomeres and nucleoli were analyzed by fluorescence in situ hybridization in seven diploid species (2n = 10 - 16) representing major crucifer clades with an up to 26-fold variation in genome size (160 Mb - 4 260 Mb). Nucleolus-associated telomere clustering was confirmed in arabidopsis (157 Mb) and was newly identified as the major nuclear phenotype in other species with a small genome (215 - 381 Mb). In large-genome species (2 611 - 4 264 Mb), centromeres and telomeres adopted either a Rabl-like configuration or dispersed distribution in the nuclear interior; telomeres only rarely associated with the nucleolus. In Arabis cypria (381 Mb) and Bunias orientalis (2 611 Mb), tissue-specific patterns deviating from the major nuclear phenotypes were observed in anther and stem tissues, respectively. The rosette-like configuration, including nucleolus-associated telomere clustering in small-genome species from different infrafamiliar clades, suggests that genomic properties rather than phylogenetic position, determine the interphase nuclear organization. Our data suggest that nuclear genome size, average chromosome size and degree of longitudinal chromosome compartmentalization affect interphase chromosome organization in crucifer genomes.