3D Chromatin Architecture of Large Plant Genomes Determined by Local A/B Compartments  

作　　者：Pengfei Dong Xiaoyu Tu Po-Yu Chu Peitao Lu Ning Zhu Donald Grierson Baijuan Du Pinghua Li Silin Zhong 

机构地区：[1]State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Tai'an, Shandong, China [2]State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China [3]Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Hangzhou, Zhejiang, China [4]These authors contributed equally to this article.

出　　处：《Molecular Plant》2017年第12期1497-1509,共13页分子植物（英文版）

摘　　要：The spatial organization of the genome plays an important role in the regulation of gene expression. How- ever, the core structural features of animal genomes, such as topologically associated domains （TADs） and chromatin loops, are not prominent in the extremely compact Arabidopsis genome. In this study, we examine the chromatin architecture, as well as their DNA methylation, histone modifications, accessible chromatin, and gene expression, of maize, tomato, sorghum, foxtail millet, and rice with genome sizes ranging from 0.4 to 2.4 Gb. We found that these plant genomes can be divided into mammalian-like A/B compartments. At higher resolution, the chromosomes of these plants can be further partitioned to local AJB compartments that reflect their euchromatin, heterochromatin, and polycomb status. Chromatins in all these plants are organized into domains that are not conserved across species. They show similarity to the Drosophila compartment domains, and are clustered into active, polycomb, repressive, and interme- diate types based on their transcriptional activities and epigenetic signatures, with domain border overlaps with the local A/B compartment junctions. In the large maize and tomato genomes, we observed extensive chromatin loops. However, unlike the mammalian chromatin loops that are enriched at the TAD border, plant chromatin loops are often formed between gene islands outside the repressive domains and are closely associated with active compartments. Our study indicates that plants have complex and unique 3D chromatin architectures, which require further study to elucidate their biological functions.The spatial organization of the genome plays an important role in the regulation of gene expression. How- ever, the core structural features of animal genomes, such as topologically associated domains （TADs） and chromatin loops, are not prominent in the extremely compact Arabidopsis genome. In this study, we examine the chromatin architecture, as well as their DNA methylation, histone modifications, accessible chromatin, and gene expression, of maize, tomato, sorghum, foxtail millet, and rice with genome sizes ranging from 0.4 to 2.4 Gb. We found that these plant genomes can be divided into mammalian-like A/B compartments. At higher resolution, the chromosomes of these plants can be further partitioned to local AJB compartments that reflect their euchromatin, heterochromatin, and polycomb status. Chromatins in all these plants are organized into domains that are not conserved across species. They show similarity to the Drosophila compartment domains, and are clustered into active, polycomb, repressive, and interme- diate types based on their transcriptional activities and epigenetic signatures, with domain border overlaps with the local A/B compartment junctions. In the large maize and tomato genomes, we observed extensive chromatin loops. However, unlike the mammalian chromatin loops that are enriched at the TAD border, plant chromatin loops are often formed between gene islands outside the repressive domains and are closely associated with active compartments. Our study indicates that plants have complex and unique 3D chromatin architectures, which require further study to elucidate their biological functions.

关 键 词：Hi-C chromatin loop compartment domain local compartment 

分 类 号：Q0[生物学]