Centromeres are essential genetic elements that enable spindle microtubule attachment for chromosome segregation during mitosis and meiosis. While this function is preserved across species, centromeres display an array of dynamic features, including: (1) rapidly evolving DNA; (2) wide evolutionary diversity in size, shape and organization; (3) evidence of mutational processes to generate homogenized repetitive arrays that characterize centromeres in several species; (4) tolerance to changes in position, as in the case of neocentromeres; and (5) intrinsic fragility derived by sequence composition and secondary DNA structures. Centromere drive underlies rapid centromere DNA evolution due to the “selfish” pursuit to bias meiotic transmission and promote the propagation of stronger centromeres. Yet, the origins of other dynamic features of centromeres remain unclear. Here, we review our current understanding of centromere evolution and plasticity. We also detail the mutagenic processes proposed to shape the divergent genetic nature of centromeres. Changes to centromeres are not simply evolutionary relics, but ongoing shifts that on one side promote centromere flexibility, but on the other can undermine centromere integrity and function with potential pathological implications such as genome instability.

中文翻译：

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压力下的着丝粒：与保守功能冲突中的进化创新

着丝粒是重要的遗传元件，可在有丝分裂和减数分裂过程中使纺锤体微管附着以实现染色体分离。虽然这种功能在不同物种中都得到保留，但着丝粒显示出一系列动态特征，包括：(1) 快速进化的 DNA；(2) 大小、形状和组织方面广泛的进化多样性；(3) 产生均质重复阵列的突变过程的证据，这些重复阵列表征了多个物种的着丝粒；(4) 对位置变化的耐受性，如新着丝粒的情况；(5)由序列组成和二级DNA结构衍生的内在脆弱性。着丝粒驱动是着丝粒 DNA 快速进化的基础，因为“自私”的追求会偏向减数分裂传播并促进更强的着丝粒的繁殖。然而，着丝粒其他动态特征的起源仍不清楚。在这里，我们回顾了目前对着丝粒进化和可塑性的理解。我们还详细介绍了旨在塑造着丝粒不同遗传性质的诱变过程。着丝粒的变化不仅仅是进化遗迹，而是持续的变化，一方面促进着丝粒的灵活性，但另一方面可能破坏着丝粒的完整性和功能，并具有潜在的病理影响，例如基因组不稳定。