...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Protoplasma: An International Journal of Cell Biology >Analysis of chromatin and DNA during chromosome endoreduplication in the endosperm of Triticum durum Desf.
【24h】

Analysis of chromatin and DNA during chromosome endoreduplication in the endosperm of Triticum durum Desf.

机译：硬粒小麦胚乳染色体内复制过程中染色质和DNA的分析。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Chromatin structure was studied in nuclei of the endosperm of durum wheat (Triticum durum Desf., cv. Creso), where a large number of cells undergo chromosome endoreduplication during caryopsis development. Optical density profiles of interphase nuclei at different ploidy levels after Feulgen staining were determined cytophotometrically. It was observed that, within each development stage, polyploid nuclei (6-12C and 12-24C) show more condensed chromatin than euploid nuclei (3-6C): this should indicate that endoreduplication is accompanied by some reduction of nuclear activity. Within the same ploidy level, 3-6C and 6-12C nuclei become increasingly condensed with development (except for the last stage), while 12-24C nuclei are identical at all stages. DNA methylation at different stages of caryopsis development was then analyzed in genomic DNA, highly repeated sequences and ribosomal DNA, by digestion with cytosine-methylation-sensitive restriction enzymes. We observed that (i), depending on the enzyme, DNA from caryopses may show higher mean length than DNA from shoot apices and variations occur during endosperm development; (ii) highly repeated DNA sequences also show some variation in base methylation between apices and endosperms and among endosperm development stages, even though to a lesser extent than genomic DNA; (iii) rDNA shows variations only between endosperm and apices while no variation was observed among endosperm development stages in relation to chromosome endoreduplication. Our data may be explained by assuming the occurrence, during endosperm development, of processes of chromatin condensation possibly involved in silencing the activity of extra copies of DNA resulting from chromosome endoreduplication. At least in part, DNA methylation is involved in the process of chromatin condensation. rDNA shows no variation during endosperm development: this suggests that rDNA copies are actively transcribed in both triploid and endoreduplicated nuclei. [References: 37]
机译：在硬质小麦（Triticum durum Desf。，cv。Creso）的硬质小麦胚乳核中研究了染色质结构，其中大量细胞在颖果发育过程中进行染色体核内复制。用Feulgen染色后，用光度法确定了不同倍性水平下的相间核的光密度分布。观察到，在每个发育阶段，多倍体核（6-12C和12-24C）比整倍体核（3-6C）显示更多的染色质浓缩：这应该表明核内复制伴随着核活性的降低。在相同的倍数水平上，3-6C和6-12C原子核与发育的关系越来越紧密（最后阶段除外），而12-24C原子核在所有阶段都是相同的。然后，通过用胞嘧啶甲基化敏感的限制性内切酶消化，分析了颖果发育不同阶段的DNA甲基化，包括基因组DNA，高度重复的序列和核糖体DNA。我们观察到（i）依赖于酶的种类，来自颈果的DNA的平均长度可能比来自茎尖的DNA的平均长度长，并且胚乳发育期间会发生变异; （ii）高度重复的DNA序列在顶点和胚乳之间以及胚乳发育阶段之间也显示出碱基甲基化的某些变化，尽管程度不及基因组DNA。 （iii）rDNA仅在胚乳和顶点之间显示变异，而在胚乳发育阶段之间未观察到与染色体内复制有关的变异。我们的数据可以通过假设在胚乳发育过程中发生的染色质浓缩过程的发生来解释，该过程可能涉及沉默由染色体核内复制产生的额外DNA拷贝的活性。至少部分地，DNA甲基化与染色质浓缩过程有关。 rDNA在胚乳发育过程中没有变化：这表明rDNA拷贝在三倍体和核内复制的核中都被活跃转录。 [参考：37]

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号