Discovery of an unconventional centromere in budding yeast redefines evolution of point centromeres.
Discovery of an unconventional centromere in budding yeast redefines evolution of point centromeres.
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DOI：
10.1016/j.cub.2015.06.023
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发表时间：
2015-08-03
期刊：
影响因子：
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通讯作者：
Tanaka TU
中科院分区：
文献类型：
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作者：
Kobayashi N;Suzuki Y;Schoenfeld LW;Müller CA;Nieduszynski C;Wolfe KH;Tanaka TU
着丝粒是促进动粒组装以实现染色体分离的染色体区域。在许多真核生物中，着丝粒由多达兆个碱基对的DNA组成。在这样的“区域着丝粒”上，动粒组装主要由表观遗传调节来定义。相比之下，芽殖酵母（芽殖酵母科）的进化枝具有120-200个碱基对的DNA的“点着丝粒”，其上的动粒组装由共有DNA序列定义。在进化过程中，芽殖酵母获得了点着丝粒，取代了祖先的区域着丝粒。所有已知的点着丝粒在不同的酵母物种共享共同的共识DNA元件（CDE），这意味着他们只进化了一次，并在整个进化过程中保持基本不变。在这里，我们确定了一个酵母着丝粒，挑战这一观点：即芽殖酵母Naumovozyma castellii是第一个非常规的点着丝粒独特的CDE。卡氏猪笼草的着丝粒CDE是着丝粒功能所必需的，但与其他点着丝粒中的CDE具有不同的DNA序列。卡氏猪笼草着丝粒周围的基因顺序分析表明它们独特的、独立的进化起源。然而，它们仍然被CBF 3复合物的直系同源物结合，该复合物识别其他点着丝粒中的CDE。这种新型的点着丝粒起源于卡氏猪笼草与其近亲Daimovozyma dairenensis之间的分歧之前，并通过广泛的基因组重排散布到所有的卡氏猪笼草染色体上。因此，与传统观点相反，点着丝粒可以经历快速的进化变化。这些发现为点着丝粒的进化提供了新的见解。在芽殖酵母N. castellii中发现了一种新的点着丝粒它的DNA序列和进化起源与其它点着丝粒不同N. castellii的着丝粒被识别其它点着丝粒的CBF 3结合与传统观点相反，点着丝粒在进化中可以迅速变化所有已知的点着丝粒都具有共同的DNA序列和单一的进化起源。小林等人在芽殖酵母N. castellii中发现了一种新型的点着丝粒。它的DNA序列和进化起源与其它点着丝粒不同。新着丝粒的发现重新定义了点着丝粒的进化。
Centromeres are the chromosomal regions promoting kinetochore assembly for chromosome segregation. In many eukaryotes, the centromere consists of up to mega base pairs of DNA. On such “regional centromeres,” kinetochore assembly is mainly defined by epigenetic regulation. By contrast, a clade of budding yeasts (Saccharomycetaceae) has a “point centromere” of 120–200 base pairs of DNA, on which kinetochore assembly is defined by the consensus DNA sequence. During evolution, budding yeasts acquired point centromeres, which replaced ancestral, regional centromeres. All known point centromeres among different yeast species share common consensus DNA elements (CDEs), implying that they evolved only once and stayed essentially unchanged throughout evolution. Here, we identify a yeast centromere that challenges this view: that of the budding yeast Naumovozyma castellii is the first unconventional point centromere with unique CDEs. The N. castellii centromere CDEs are essential for centromere function but have different DNA sequences from CDEs in other point centromeres. Gene order analyses around N. castellii centromeres indicate their unique, and separate, evolutionary origin. Nevertheless, they are still bound by the ortholog of the CBF3 complex, which recognizes CDEs in other point centromeres. The new type of point centromere originated prior to the divergence between N. castellii and its close relative Naumovozyma dairenensis and disseminated to all N. castellii chromosomes through extensive genome rearrangement. Thus, contrary to the conventional view, point centromeres can undergo rapid evolutionary changes. These findings give new insights into the evolution of point centromeres. A new type of point centromere has been identified in budding yeast N. castellii Its DNA sequence and evolutionary origin are different from other point centromeres N. castellii centromeres are bound by CBF3 that recognizes other point centromeres Contrary to the conventional view, point centromeres can change rapidly in evolution All known point centromeres share common DNA sequences and a single evolutionary origin. Kobayashi et al. have identified a new type of point centromere in budding yeast N. castellii. Its DNA sequence and evolutionary origin are different from other point centromeres. Discovery of the new centromere redefines the evolution of point centromeres.