自发的单核酸替代和微卫星突变具有不同的健康效应分布
bioRxiv : the preprint server for biology
|July 18, 2023
概括
新突变极大地损害了酵母的生长速度,频繁的,小效果的有害突变对不断演变的血统造成了重大负担. 简单的序列重复,虽然平均而言很小,但会影响进化. 关键词:酵母,突变,生长速度,进化,大脑菌.
科学领域:
- 进化生物学是进化的生物学.
- 微生物遗传学微生物遗传学
背景情况:
- 突变是进化的基础,但新突变的健康效应是复杂的.
- 有害的突变,特别是那些具有小影响的突变,可以显著影响像酵母这样的克隆生物的进化轨迹.
- 准确测量小效应突变的速率和影响是具有挑战性的.
研究的目的:
- 精确推断突变对Saccharomyces cerevisiae生长速度的影响的分布.
- 调查频繁,小效果有害突变所造成的负担.
- 为了区分单核酸替代和简单序列重复对酵母菌生长的影响.
主要方法:
- 在Saccharomyces cerevisiae的突变积累菌株上使用了高通量时隔显微镜.
- 分析的重点是推断突变对细胞生长速度的影响分布.
- 带有突变在野生类型和滑动修复缺陷背景中积累的菌株被用来区分突变类型.
主要成果:
- 对酵母生长率的突变效应主要是负面的,并且高度倾向于非常小的效应大小.
- 有害突变的发生频率足以对不断演变的血统造成重大负担.
- 单核酸替代和简单序列重复作用对生长率有明显的影响,许多简单序列重复作用改变了生长,尽管平均效应很小.
结论:
- 有害的突变,特别是频繁的小效应的突变,在塑造酵母的进化动态方面发挥着至关重要的作用.
- 简单的序列重复,尽管它们的平均效果很小,但由于它们的频率,它们对进化影响有很大的贡献.
- 了解突变效应的分布是预测克隆进化的群体进化结果的关键.
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