重组热点悖论:PRDM9与其目标地点之间的共同进化
Francisco Úbeda1, Frédéric Fyon1, Reinhard Bürger2
1Department of Biology, Royal Holloway University of London, Egham TW20 0EX, UK.
Theoretical population biology
|July 14, 2023
概括
重组热点虽然是自我破坏性的,但由于突变,基因转换和生育选择的平衡,在脊椎动物中仍然存在. 基因PRDM9影响热点活动,解决重组热点悖论.
科学领域:
- 遗传学和进化生物学
- 人口遗传学 人口遗传学
- 分子生物学分子生物学
背景情况:
- 重组热点是基因组区域,其重组率较高,主要由脊椎动物的PRDM9基因决定.
- 由于基因转换,这些热点本质上是自我破坏性的,导致一个悖论,即尽管它们倾向于消失,但它们仍然大量存在.
- 重组热点的持续存在挑战了进化论,需要解释它们的持续存在.
研究的目的:
- 研究维护脊椎动物基因组中大量重组热点的机制.
- 通过模拟进化力量的相互作用来解决重组热点悖论.
- 了解PRDM9基因调节在热点动态中的作用.
主要方法:
- 制定一个共同进化模型,包括序列特异性基因转换,生育选择和反复突变.
- 基频率动态及其由此产生的振荡的分析.
- 模拟多个等位基因和多个标,以评估它们对基因组重组概率的影响.
主要成果:
- 该模型表明,等位基频率的振荡导致稳定的极限周期,防止热点灭绝.
- 生育选择,当它比基因转换弱时,可以复活垂死的热点,保持它们的总数.
- 经常发生的突变平衡了热点死亡和复活,确保了它们的进化持久性.
- 多个等位基因和标有助于混乱或异步振荡,稳定平均基因组重组概率.
- PRDM9的表达水平与成为热点的目标的比例相关.
结论:
- 同进化模型成功地解释了重组热点的持久性,解决了重组热点悖论.
- 突变,基因转换和生育选择之间的平衡对于在进化时间尺度上保持热点活动至关重要.
- PRDM9的调节作用是调节热点分布和基因组重组的关键.
- 该研究提供了可测试的关于突变概率,生育选择和热点寿命的预测.
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