A 'selfish' B chromosome induces genome elimination by disrupting the histone code in the jewel wasp Nasonia vitripennis
A 'selfish' B chromosome induces genome elimination by disrupting the histone code in the jewel wasp Nasonia vitripennis
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DOI：
10.1038/srep42551
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发表时间：
2017-02-13
影响因子：
4.6
通讯作者：
Ferree, Patrick M.
中科院分区：
文献类型：
--
作者：
Aldrich, John C.;Leibholz, Alexandra;Ferree, Patrick M.
基因组内冲突描述了一种现象，其中遗传元件以牺牲整个基因组为代价“自私”地发挥作用以获得传播优势。一个非必需的，自私的B染色体被称为父性比（PSR）诱导完全消除的精子来源的遗传物质的宝石黄蜂Nasonia vitripennis。PSR阻止父体染色质在第一次胚胎有丝分裂期间形成染色体，导致其丢失。虽然PSR是由父亲传播的，但它避免了自我消除，以便被遗传。我们研究了受精胚胎中正常基因组和PSR染色体上DNA包装组蛋白的重要翻译后修饰。三个组蛋白标记-H3 K9 me 2，3，H3 K27 me 1和H4 K20 me 1-在进入有丝分裂之前变得异常富集并扩散到精子染色质上的异位位置。相比之下，其他组蛋白标记和DNA甲基化不受PSR的影响，这表明它对父亲基因组的影响是特定于组蛋白标记的子集。与父系衍生的基因组相反，PSR染色体明显缺乏H3 K27 me 1和H4 K20 me 1标记。这些发现强烈表明，PSR通过在受精后破坏至少三个组蛋白标记而导致父本基因组消除，而PSR通过避开这些标记中的两个而避免自我消除。
Intragenomic conflict describes a phenomenon in which genetic elements act 'selfishly' to gain a transmission advantage at the expense of the whole genome. A non-essential, selfish B chromosome known as Paternal Sex Ratio (PSR) induces complete elimination of the sperm-derived hereditary material in the jewel wasp Nasonia vitripennis. PSR prevents the paternal chromatin from forming chromosomes during the first embryonic mitosis, leading to its loss. Although paternally transmitted, PSR evades self-elimination in order to be inherited. We examined important post-translational modifications to the DNA packaging histones on the normal genome and the PSR chromosome in the fertilized embryo. Three histone marks -H3K9me2,3, H3K27me1, and H4K20me1 - became abnormally enriched and spread to ectopic positions on the sperm's chromatin before entry into mitosis. In contrast, other histone marks and DNA methylation were not affected by PSR, suggesting that its effect on the paternal genome is specific to a subset of histone marks. Contrary to the paternally derived genome, the PSR chromosome was visibly devoid of the H3K27me1 and H4K20me1 marks. These findings strongly suggest that PSR causes paternal genome elimination by disrupting at least three histone marks following fertilization, while PSR avoids self-elimination by evading two of these marks.