Abstract：
In eukaryotic genomes, rDNA generally resides as a highly repetitive and dynamic structure, making it difficult to study. Here, a synthetic rDNA array on chromosome III in budding yeast was constructed to serve as the sole source of rRNA. Utilizing the loxPsym site within each rDNA repeat and the Cre recombinase, we were able to reduce the copy number to as few as eight copies. Additionally, we constructed strains with two or three rDNA arrays and found that the presence of multiple arrays did not affect the formation of a single nucleolus. Although alteration of the position and number of rDNA arrays did impact the three-dimensional genome structure, the additional rDNA arrays had no deleterious influence on cell growth or transcriptomes. Overall, this study sheds light on the high plasticity of rDNA organization and opens up opportunities for future rDNA engineering.
摘要：
在真核基因组中，rDNA通常作为高度重复和动态的结构存在，使其难以学习。这里,构建出芽酵母中III号染色体上的合成rDNA阵列，以作为rRNA的唯一来源。利用每个rDNA重复和Cre重组酶中的loxPsym位点，我们能够将拷贝数减少到8份。此外,我们用两个或三个rDNA阵列构建了菌株，发现多个阵列的存在并不影响单个核仁的形成。尽管rDNA阵列的位置和数量的改变确实会影响三维基因组结构，额外的rDNA阵列对细胞生长或转录组没有有害影响。总的来说,这项研究揭示了rDNA组织的高可塑性，并为将来的rDNA工程开辟了机会。
