Centromeres are chromosomal regions that are crucial for chromosome segregation during mitosis and meiosis, and failed centromere formation can contribute to chromosomal anomalies. Despite this conserved function, centromeres differ significantly between and even within species. Thus far, systematic studies into the organization and evolution of fungal centromeres remain scarce. In this study, we identified the centromeres in each of the 10 species of the fungal genus Verticillium and characterized their organization and evolution. Chromatin immunoprecipitation of the centromere-specific histone CenH3 (ChIP-seq) and chromatin conformation capture (Hi-C) followed by high-throughput sequencing identified eight conserved, large (∼150-kb), AT-, and repeat-rich regional centromeres that are embedded in heterochromatin in the plant pathogen Verticillium dahliae. Using Hi-C, we similarly identified repeat-rich centromeres in the other Verticillium species. Strikingly, a single degenerated long terminal repeat (LTR) retrotransposon is strongly associated with centromeric regions in some but not all Verticillium species. Extensive chromosomal rearrangements occurred during Verticillium evolution, of which some could be linked to centromeres, suggesting that centromeres contributed to chromosomal evolution. The size and organization of centromeres differ considerably between species, and centromere size was found to correlate with the genome-wide repeat content. Overall, our study highlights the contribution of repetitive elements to the diversity and rapid evolution of centromeres within the fungal genus Verticillium.

中文翻译：

---

重复元件有助于黄萎病真菌属着丝粒的多样性和进化。


着丝粒是对有丝分裂和减数分裂期间染色体分离至关重要的染色体区域，着丝粒形成失败可能导致染色体异常。尽管有这种保守的功能，但着丝粒在物种之间甚至物种内部都存在显着差异。迄今为止，对真菌着丝粒的组织和进化的系统研究仍然很少。在这项研究中，我们鉴定了 10 种轮枝菌属真菌中每一种的着丝粒，并描述了它们的组织和进化特征。着丝粒特异性组蛋白 CenH3 的染色质免疫沉淀 (ChIP-seq) 和染色质构象捕获 (Hi-C)，然后进行高通量测序，鉴定出 8 个保守、大 (∼150-kb)、AT 和重复丰富的区域着丝粒嵌入植物病原体大丽黄萎病菌的异染色质中。使用 Hi-C，我们同样在其他黄萎病菌属物种中鉴定了富含重复的着丝粒。引人注目的是，单个简并长末端重复序列（LTR）反转录转座子与一些但不是所有黄萎病菌属物种的着丝粒区域密切相关。黄萎病进化过程中发生了广泛的染色体重排，其中一些重排可能与着丝粒有关，这表明着丝粒有助于染色体进化。不同物种之间着丝粒的大小和组织差异很大，并且发现着丝粒大小与全基因组重复内容相关。总体而言，我们的研究强调了重复元件对黄萎病属真菌属内着丝粒的多样性和快速进化的贡献。