Nuclear fusions contribute to polyploidization of the gigantic nuclei in the chalazal endosperm of Arabidopsis
Nuclear fusions contribute to polyploidization of the gigantic nuclei in the chalazal endosperm of Arabidopsis
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DOI：
10.1007/s00425-004-1326-2
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发表时间：
2004-11-01
期刊：
影响因子：
4.3
通讯作者：
Grossniklaus, U
中科院分区：
文献类型：
--
作者：
Baroux, C;Fransz, P;Grossniklaus, U
体细胞多倍化被认为是提高高活性代谢细胞中基因表达水平的一种手段。最常见的机制是内复制、内有丝分裂和细胞融合。在动物和植物中，多核细胞的核通常被阻止融合。本文报道了拟南芥合点端胚乳合胞囊的细胞核。嘿是多倍体，具有一些中间倍性水平，不能归因于核内复制，表明核融合。分离的细胞核的分析，连同荧光原位杂交（FISH），发现合点胚乳的细胞核是两个或三个倍大的细胞核从外周胚乳，并有相应的倍性增加。结合对相邻核的一致观察，我们认为核融合至少部分地促进了合点胚乳多倍化的过程。对完整种子的共聚焦分析进一步表明，来自外围胚乳的游离核被并入合点端囊中，并且可能参与核融合。
Somatic polyploidization is recognized as a means to increase gene expression levels in highly active metabolic cells. The most common mechanisms are endoreplication, endomitosis and cell fusion. In animals and plants the nuclei of multinucleate cells are usually prevented from fusing. Here, we report that the nuclei from the syncytial cyst of the chalazal endosperm of Arabidopsis thaliana (L.) Heynh. are polyploid with some intermediate ploidy levels that cannot be attributed to endoreplication, suggesting nuclear fusion. Analysis of isolated nuclei, together with fluorescent in situ hybridization (FISH), revealed that nuclei from the chalazal endosperm are two or three times bigger than the nuclei from the peripheral endosperm and have a corresponding increase in ploidy. Together with the consistent observation of adjoined nuclei, we propose that nuclear fusion contributes, at least in part, to the process of polyploidization in the chalazal endosperm. Confocal analysis of intact seeds further suggested that free nuclei from the peripheral endosperm get incorporated into the chalazal cyst and likely participate in nuclear fusions.