在巨大的基因组中,DNA的增加和损失无法追踪可转移元素与宿主沉默相互作用的差异
Jie Wang1, Guangpu Zhang2, Cheng Sun3
1Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China. wangjie@cib.ac.cn.
Communications biology
|May 6, 2025
概括
巨大的基因组通过可转移元素 (TE) 积累DNA,但的基因组大小与TE活动或抑制无关. 令人惊的是,TE多样性随着基因组大小的增加而增加.
科学领域:
- 基因组学就是基因组学.
- 进化生物学 进化生物学
- 分子生物学分子生物学
背景情况:
- 基因组大小的进化受到可转移元素 (TE) 的影响,即可以复制和插入到新的基因组位置的DNA序列.
- 脊椎动物采用复杂的机制,包括PIWI相互作用RNAs (piRNAs) 和KRAB-指蛋白 (KRAB-ZFPs),以抑制TE活性并保持基因组完整性.
- 共同进化的共进化过程.
- 在军备竞赛中.
- 在TEs和宿主抑制系统之间是基因组动态的关键驱动因素,抑制强度理论上与TE健身成本有关.
研究的目的:
- 为了研究基因组大小,TE动态和巨大的脊椎动物基因组中的宿主抑制途径之间的关系.
- 分析6种具有异常大基因组 (21.349.9 Gb) 的鱼物种的TE扩散历史,删除率和社区多样性.
- 检查与基因组大小和TE积累相关的TEs和抑制途径的淋巴体表达.
主要方法:
- 对六个的基因组进行比较基因组学分析.
- 可转移元素 (TE) 扩散历史和删除率的量化.
- 在基因组中评估TE社区的多样性.
- 对TEs和宿主抑制因子 (piRNA和KRAB-ZFP通路) 的淋巴腺表达模式的分析.
主要成果:
- 研究发现,与卵巢相比,丸中的TE活性更高,与男性生殖腺中KRAB-ZFP抑制的减少有关.
- 与预期相反,基因组大小和扩张与TE删除率,增殖史,表达水平或宿主抑制效率无关.
- 在基因组大小和TE社区多样性之间观察到显著的正相关性,这一发现与已建立的理论模型有所不同.
结论:
- 这项研究挑战了 TE 抑制强度直接与极大基因组中的基因组大小相匹配的观念.
- 巨大的基因组中随机TE积累可能来自TE宿主对抗,可能受到大型细胞环境中的杂分子相互作用的影响.
- TE社区的多样性随着基因组大小的增加而增加,这表明在异常大的基因组中存在新的进化动态.
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