rDNA, the genes encoding the RNA components of ribosomes (rRNA), are highly repetitive in all eukaryotic genomes, containing 100s to 1000s of copies, to meet the demand for ribosome biogenesis. rDNA genes are arranged in large stretches of tandem repeats, forming loci that are highly susceptible to copy loss due to their repetitiveness and active transcription throughout the cell cycle. Despite this inherent instability, rDNA copy number is generally maintained within a particular range in each species, pointing to the presence of mechanisms that maintain rDNA copy number in a homeostatic range. In this review, we summarize the current understanding of these maintenance mechanisms and how they sustain rDNA copy number throughout populations.

中文翻译：

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rDNA拷贝数维护机制。

rDNA是编码核糖体（rRNA）RNA成分的基因，在所有真核基因组中都具有高度重复性，包含100s至1000s的拷贝，可以满足对核糖体生物发生的需求。rDNA基因以大段串联重复序列排列，形成基因座，由于它们在整个细胞周期中的重复性和活性转录，它们极易受到复制丢失的影响。尽管存在这种固有的不稳定性，但是通常在每个物种中将rDNA拷贝数保持在特定范围内，这表明存在将rDNA拷贝数保持在体内平衡范围内的机制。在这篇综述中，我们总结了目前对这些维持机制的理解，以及它们如何在整个种群中维持rDNA拷贝数。