Transcriptional repression mechanisms of nucleolus organizer regions (NORs) in humans and chimpanzees
Transcriptional repression mechanisms of nucleolus organizer regions (NORs) in humans and chimpanzees
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DOI：
10.1023/b:chro.0000021911.43225.eb
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发表时间：
2004-01-01
影响因子：
2.6
通讯作者：
Hirai, H
中科院分区：
文献类型：
--
作者：
Guillén, AKZ;Hirai, Y;Hirai, H
与核仁组成区（NORs）转录失活相关的多态性在许多动物，特别是人类中已有报道。然而，这种变化的确切病因并不总是清楚的。我们进行了分析，以调查在人类和黑猩猩的阻遏机制，使用FISH（荧光原位杂交）与18 S rDNA，Ag-NOR（银硝酸盐）染色，C-显带，和原位缺口翻译技术与HpaII限制性内切酶。对48名人类和46名黑猩猩的研究表明，至少有三种不同的机制导致NORs失活。其中包括：（1）rDNA的消除;（2）DNA甲基化;（3）由于异染色质（C带）和/或端粒诱导的位置效应导致的基因沉默。
Polymorphisms related to transcriptional inactivation of nucleolus organizer regions (NORs) have long been described in many animals, particularly humans. However, the precise aetiology of such variations is not always clear. We conducted analyses to investigate the repression mechanisms in humans and chimpanzees using FISH (fluorescence in situ hybridisation) with 18S rDNA, Ag-NOR (silver nitrate) staining, C-banding, and the in situ nick translation technique with the HpaII restriction enzyme. Examination of 48 humans and 46 chimpanzees suggested that there are at least three different mechanisms that produce inactivation of NORs. These include: (1) elimination of rDNA; (2) DNA methylation; (3) gene silencing due to position effects induced by heterochromatin (C-bands) and/or telomeres.