De novo centromere formation on a chromosome fragment in maize
De novo centromere formation on a chromosome fragment in maize
复制标题
玉米染色体片段上着丝粒的从头形成
DOI：
10.1073/pnas.1303944110
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发表时间：
2013-04-09
影响因子：
11.1
通讯作者：
Han, Fangpu
中科院分区：
文献类型：
--
作者：
Fu, Shulan;Lv, Zhenling;Han, Fangpu
着丝粒是染色体上组织动粒的部分，在有丝分裂和减数分裂期间，动粒介导染色体运动。Stadler和Roman在20世纪40年代从UV照射的材料中描述了来自染色体3的小片段，称为重复3a（Dp 3a）[Stadler LJ，Roman H（1948）Genetics 33（3）：273-303]。Dp 3a的遗传行为让人联想到环状染色体，但荧光原位杂交检测到两端的端粒，表明其为线性结构。这个小染色体没有可检测的典型着丝粒序列，但包含一个具有功能性着丝粒蛋白特征的位点，如CENH 3（着丝粒特异性H3组蛋白变体）和CENP-C（一种基础动粒蛋白），表明染色质片段上的着丝粒从头形成。为了检查与CENH 3相关的序列，使用来自具有和不具有Dp 3a染色体的幼苗的材料，用抗CENH 3抗体进行染色质免疫沉淀。从Dp 3a样品的ChIP测序读数中检测到新峰。该峰位于3号染色体长臂内，全长350 kb，覆盖22个基因。总的来说，这些结果定义的行为和分子特征的从头着丝粒形成的Dp 3a染色体，这可能揭示了新的着丝粒位点在进化过程中的启动。
The centromere is the part of the chromosome that organizes the kinetochore, which mediates chromosome movement during mitosis and meiosis. A small fragment from chromosome 3, named Duplication 3a (Dp3a), was described from UV-irradiated materials by Stadler and Roman in the 1940s [Stadler LJ, Roman H (1948) Genetics 33(3):273–303]. The genetic behavior of Dp3a is reminiscent of a ring chromosome, but fluoresecent in situ hybridization detected telomeres at both ends, suggesting a linear structure. This small chromosome has no detectable canonical centromeric sequences, but contains a site with protein features of functional centromeres such as CENH3, the centromere specific H3 histone variant, and CENP-C, a foundational kinetochore protein, suggesting the de novo formation of a centromere on the chromatin fragment. To examine the sequences associated with CENH3, chromatin immunoprecipitation was carried out with anti-CENH3 antibodies using material from young seedlings with and without the Dp3a chromosome. A novel peak was detected from the ChIP-Sequencing reads of the Dp3a sample. The peak spanned 350 kb within the long arm of chromosome 3 covering 22 genes. Collectively, these results define the behavior and molecular features of de novo centromere formation in the Dp3a chromosome, which may shed light on the initiation of new centromere sites during evolution.