Jabbari Kamel, Bernardi Giorgio
Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Straße 9B, Köln, Germany.
Science Department, Roma Tre University, Viale Marconi, Rome, Italy, and Stazione Zoologica Anton Dohrn, Villa Comunale, Naples, Italy.
PLoS One. 2017 Jan 6;12(1):e0168023. doi: 10.1371/journal.pone.0168023. eCollection 2017.
A recent investigation showed the existence of correlations between the architectural features of mammalian interphase chromosomes and the compositional properties of isochores. This result prompted us to compare maps of the Topologically Associating Domains (TADs) and of the Lamina Associated Domains (LADs) with the corresponding isochore maps of mouse and human chromosomes. This approach revealed that: 1) TADs and LADs correspond to isochores, i.e., isochores are the genomic units that underlie chromatin domains; 2) the conservation of TADs and LADs in mammalian genomes is explained by the evolutionary conservation of isochores; 3) chromatin domains corresponding to GC-poor isochores (e.g., LADs) show not only self-interactions but also intrachromosomal interactions with other domains also corresponding to GC-poor isochores even if located far away; in contrast, chromatin domains corresponding to GC-rich isochores (e.g., TADs) show more localized chromosomal interactions, many of which are inter-chromosomal. In conclusion, this investigation establishes a link between DNA sequences and chromatin architecture, explains the evolutionary conservation of TADs and LADs and provides new information on the spatial distribution of GC-poor/gene-poor and GC-rich/gene-rich chromosomal regions in the interphase nucleus.
最近的一项研究表明，哺乳动物间期染色体的结构特征与等密度区的组成特性之间存在相关性。这一结果促使我们将拓扑相关结构域（TADs）和核纤层相关结构域（LADs）的图谱与小鼠和人类染色体的相应等密度区图谱进行比较。这种方法揭示了：1）TADs和LADs对应于等密度区，即等密度区是构成染色质结构域的基因组单位；2）哺乳动物基因组中TADs和LADs的保守性可以通过等密度区的进化保守性来解释；3）对应于GC含量低的等密度区的染色质结构域（如LADs）不仅显示自身相互作用，还显示与其他同样对应于GC含量低的等密度区的染色质结构域的染色体内相互作用，即使它们相距很远；相反，对应于GC含量高的等密度区的染色质结构域（如TADs）显示出更局部化的染色体相互作用，其中许多是染色体间的相互作用。总之，这项研究建立了DNA序列与染色质结构之间的联系，解释了TADs和LADs的进化保守性，并提供了关于间期细胞核中GC含量低/基因含量低和GC含量高/基因含量高的染色体区域空间分布的新信息。
