LITTLE NUCLEI 1 and 4 Regulate Nuclear Morphology in Arabidopsis thaliana
LITTLE NUCLEI 1 and 4 Regulate Nuclear Morphology in Arabidopsis thaliana
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DOI：
10.1093/pcp/pct031
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发表时间：
2013-04-01
影响因子：
4.9
通讯作者：
Takagi, Shingo
中科院分区：
文献类型：
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作者：
Sakamoto, Yuki;Takagi, Shingo
植物细胞核的形态因物种、器官、组织和细胞类型而异。然而，人们对维持核形态的机制和因素知之甚少。由于即使在体内和体外经过细胞骨架抑制剂处理后，细胞核仍保持其形状，因此我们假设核纤层参与其中，核纤层在动物核形态的调节中发挥着关键作用。通过质谱分析从拟南芥叶中分离出的粗核纤层部分，并鉴定了推定的核纤层蛋白。在它们的T-DNA插入系中，小核1（linc1）和linc4破坏株的核比野生型植物的核更球形。因为拟南芥含有四个LINC基因，所以我们制备了所有单破坏子以及linc1/4和linc2/3双破坏子。在叶表皮细胞中，除linc3外，所有linc破坏株的细胞核圆形指数均显着高于野生型植物。 LINC1 和/或 LINC4 破坏的影响程度显着高于 LINC2 破坏的影响程度。 linc1、linc4 和 linc1/4 破坏株的核面积明显小于野生型植物。无论核形态存在缺陷，所有突变体都表现出正常的倍性水平。在间期细胞中，LINC1和LINC4主要位于核外围，而LINC2位于核质中，LINC3在这两个区域均检测到。在有丝分裂根尖细胞中，从中期到后期，LINC1与染色体共定位，而其他LINC则分散在细胞质中。
The morphology of plant nuclei varies among different species, organs, tissues and cell types. However, mechanisms and factors involved in the maintenance of nuclear morphology are poorly understood. Because nuclei retain their shapes even after cytoskeletal inhibitor treatments both in vivo and in vitro, we assumed involvement of the nuclear lamina, which plays a critical role in the regulation of nuclear morphology in animals. The crude nuclear lamina fraction isolated from Arabidopsis thaliana leaves was analyzed by mass spectrometry, and putative nuclear lamina proteins were identified. Among their T-DNA insertion lines, nuclei of little nuclei1 (linc1) and linc4 disruptants were more spherical than those of wild-type plants. Because A. thaliana harbors four LINC genes, we prepared all single and linc1/4 and linc2/3 double disruptants. In leaf epidermal cells, the circularity index of the nucleus in all linc disruptants except linc3 was significantly higher than that in the wild-type plants. The extent of the effects of LINC1 and/or LINC4 disruption was significantly higher than that of the effects of LINC2 disruption. The nuclear area was significantly smaller in the linc1, linc4 and linc1/4 disruptants than in the wild-type plants. Regardless of the defects in nuclear morphology, all linc disruptants exhibited a normal ploidy level. In interphase cells, LINC1 and LINC4 were mainly localized to the nuclear periphery, whereas LINC2 was in the nucleoplasm and LINC3 was detected in both regions. From prometaphase to anaphase in mitotic root tip cells, LINC1 was co-localized with chromosomes, whereas other LINCs were dispersed in the cytoplasm.