Quantitative Analysis of Chromosome Polytenization in Synthetic Autopolyploids of Arabidopsis thaliana
Quantitative Analysis of Chromosome Polytenization in Synthetic Autopolyploids of Arabidopsis thaliana
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DOI：
10.1508/cytologia.85.189
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发表时间：
2020-09-01
期刊：
影响因子：
1
通讯作者：
Iwamoto, Akitoshi
中科院分区：
文献类型：
--
作者：
Kikuchi, Suzuka;Iwamoto, Akitoshi
对同源多倍体细胞核内染色体多聚化的分析有助于了解多倍体对植物生长的影响。我们进行荧光原位杂交（FISH）分析与着丝粒DNA探针的二倍体和合成同源多倍体系列（四倍体，六倍体，八倍体）的拟南芥观察和定量染色体在多倍体植物的多伸化。FISH分析表明，多倍体菌株基本基因组中着丝粒序列的信号数目小于细胞核中的染色体数目，表明染色体已发生了多延化。此外，随着倍性程度的增加，染色体的多伸化程度也随之增加。这一结果表明，多倍体植物细胞增殖的抑制可能与染色体的多伸化有关。FISH分析证实，所有菌株核内复制细胞的细胞核内均发生了染色体多伸化。我们还表明，根据核内复制水平的多缩程度增加。特别是，核内复制的八倍体细胞的细胞核中的染色体是高度多张力化的，这可能与在这些细胞中观察到的严重生长抑制有关。这是第一份明确表明染色体多伸化不仅发生在核内复制细胞的细胞核中，而且也发生在同源多倍体植物的非核内复制细胞（具有基本基因组的细胞）的细胞核中。
The analysis of chromosome polytenization in the nuclei of autopolyploids may help to determine how polyploidy affects plant growth. We performed fluorescence in situ hybridization (FISH) analysis with a centromeric DNA probe on diploid and synthetic autopolyploid series (tetraploid, hexaploid, and octaploid) of Arabidopsis thaliana to observe and quantify chromosome polytenization in polyploid plants. Our FISH analysis revealed that the number of signals of centromeric sequence was smaller than the number of chromosomes in the nuclei of basic genomes in polyploid strains, which indicates the polytenization of chromosomes. In addition, the degree of chromosome polytenization increased as the degree of ploidy increased. This result suggests that the suppression of cell proliferation in polyploid plants may be related to chromosome polytenization. The FISH analysis confirmed that chromosome polytenization occurred in the nuclei of endoreduplicated cells in all strains. We also demonstrated that the degree of polytenization increased according to the endoreduplication level. In particular, chromosomes in the nuclei of endoreduplicated octaploid cells were highly polytenized, which is likely related to the severe growth suppression observed in these cells. This is the first report to explicitly show that chromosome polytenization occurs not only in the nuclei of endoreduplicated cells but also in those of non-endoreduplicated cells (cells with a basic genome) in autopolyploid plants.