Catacchio C R, Ragone R, Chiatante G, Ventura M
University of Bari Aldo Moro, Department of Biology, Via Orabona 4, Bari, 70125, Italy.
Sci Rep. 2015 Sep 21;5:14189. doi: 10.1038/srep14189.
The centromere/kinetochore interaction is responsible for the pairing and segregation of replicated chromosomes in eukaryotes. Centromere DNA is portrayed as scarcely conserved, repetitive in nature, quickly evolving and protein-binding competent. Among primates, the major class of centromeric DNA is the pancentromeric α-satellite, made of arrays of 171 bp monomers, repeated in a head-to-tail pattern. α-satellite sequences can either form tandem heterogeneous monomeric arrays or assemble in higher-order repeats (HORs). Gorilla centromere DNA has barely been characterized, and data are mainly based on hybridizations of human alphoid sequences. We isolated and finely characterized gorilla α-satellite sequences and revealed relevant structure and chromosomal distribution similarities with other great apes as well as gorilla-specific features, such as the uniquely octameric structure of the suprachromosomal family-2 (SF2). We demonstrated for the first time the orthologous localization of alphoid suprachromosomal families-1 and -2 (SF1 and SF2) between human and gorilla in contrast to chimpanzee centromeres. Finally, the discovery of a new 189 bp monomer type in gorilla centromeres unravels clues to the role of the centromere protein B, paving the way to solve the significance of the centromere DNA's essential repetitive nature in association with its function and the peculiar evolution of the α-satellite sequence.
着丝粒/动粒相互作用负责真核生物中复制染色体的配对和分离。着丝粒DNA被描述为几乎不保守、本质上具有重复性、快速进化且具有蛋白质结合能力。在灵长类动物中,着丝粒DNA的主要类型是泛着丝粒α卫星,由171 bp单体的阵列组成,以头对尾的模式重复。α卫星序列既可以形成串联异质单体阵列,也可以组装成高阶重复序列(HORs)。大猩猩着丝粒DNA几乎没有得到表征,数据主要基于人类α卫星序列的杂交。我们分离并精细表征了大猩猩α卫星序列,揭示了与其他大猩猩以及大猩猩特异性特征(如超染色体家族-2(SF2)独特的八聚体结构)相关的结构和染色体分布相似性。我们首次证明了人类和大猩猩之间着丝粒超染色体家族-1和-2(SF1和SF2)的直系同源定位,这与黑猩猩着丝粒不同。最后,在大猩猩着丝粒中发现一种新的189 bp单体类型,揭示了着丝粒蛋白B作用的线索,为解决着丝粒DNA基本重复性质与其功能以及α卫星序列特殊进化相关的重要性铺平了道路。