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Comparative genome analyses highlight transposon-mediated genome expansion and the evolutionary architecture of 3D genomic folding in cotton

更新时间:2021-05-12 15:30:18点击次数:172次字号:T|T
Maojun Wang, Jianying Li, Pengcheng Wang, Fang Liu, Zhenping Liu, Guannan Zhao, Zhongping Xu, Liuling Pei, Corrinne E Grover, Jonathan F Wendel, Kunbo Wang, Xianlong Zhang

Abstract

Transposable element (TE) amplification has been recognized as a driving force mediating genome size expansion and evolution, but the consequences for shaping 3D genomic architecture remains largely unknown in plants. Here, we report reference-grade genome assemblies for three species of cotton ranging three-fold in genome size, namely Gossypium rotundifolium (K2), G. arboreum (A2), and G. raimondii (D5), using Oxford Nanopore Technologies. Comparative genome analyses document the details of lineage-specific TE amplification contributing to the large genome size differences (K2, 2.44 Gb; A2, 1.62 Gb; D5, 750.19 Mb), and indicate relatively conserved gene content and synteny relationships among genomes. We found that approximately 17% of syntenic genes exhibit chromatin status change between active (“A”) and inactive (“B”) compartments, and TE amplification was associated with the increase of the proportion of A compartment in gene regions (∼ 7,000 genes) in K2 and A2 relative to D5. Only 42% of topologically associating domain (TAD) boundaries were conserved among the three genomes. Our data implicate recent amplification of TEs following formation of lineage-specific TAD boundaries. This study sheds light on the role of transposon-mediated genome expansion in the evolution of higher-order chromatin structure in plants.


原文链接:https://doi.org/10.1093/molbev/msab128