State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, Zhejiang, China.
Collaborative Innovation Center for Efficient and Green Production of Agriculture in Mountainous Areas of Zhejiang Province, College of Horticulture Science, Zhejiang A&F University, Hangzhou 311300, Zhejiang, China.
Nucleic Acids Res. 2024 May 22;52(9):4906-4921. doi: 10.1093/nar/gkae131.
Eukaryotic genomes are spatially organized within the nucleus in a nonrandom manner. However, fungal genome arrangement and its function in development and adaptation remain largely unexplored. Here, we show that the high-order chromosome structure of Fusarium graminearum is sculpted by both H3K27me3 modification and ancient genome rearrangements. Active secondary metabolic gene clusters form a structure resembling chromatin jets. We demonstrate that these jet-like domains, which can propagate symmetrically for 54 kb, are prevalent in the genome and correlate with active gene transcription and histone acetylation. Deletion of GCN5, which encodes a core and functionally conserved histone acetyltransferase, blocks the formation of the domains. Insertion of an exogenous gene within the jet-like domain significantly augments its transcription. These findings uncover an interesting link between alterations in chromatin structure and the activation of fungal secondary metabolism, which could be a general mechanism for fungi to rapidly respond to environmental cues, and highlight the utility of leveraging three-dimensional genome organization in improving gene transcription in eukaryotes.
真核生物基因组在细胞核内以非随机的方式进行空间组织。然而，真菌基因组的排列及其在发育和适应中的功能在很大程度上仍未得到探索。在这里，我们表明，禾谷镰刀菌的高级染色体结构是由 H3K27me3 修饰和古老的基因组重排共同塑造的。活跃的次级代谢基因簇形成类似于染色质射流的结构。我们证明，这些类似于射流的结构域可以对称地传播 54kb，它们在基因组中普遍存在，并与活跃的基因转录和组蛋白乙酰化相关。编码核心和功能保守的组蛋白乙酰转移酶的 GCN5 的缺失会阻止结构域的形成。在外源基因插入射流样结构域内会显著增加其转录。这些发现揭示了染色质结构改变与真菌次级代谢激活之间的有趣联系，这可能是真菌快速响应环境信号的一般机制，并强调了利用三维基因组组织来提高真核生物基因转录的效用。
