由转化合成驱动的平类酵母中突变的升高
bioRxiv : the preprint server for biology
|February 6, 2026
概括
哈普洛伊德酵母细胞表现出比双倍细胞更高的突变率,这是由于对易发生错误的转化合成 (TLS) 的依赖性增加. 删除对TLS至关重要的REV1基因,使得平分类酵母和二分类酵母之间的突变率相等.
科学领域:
- 进化生物学是进化的生物学.
- 分子遗传学 分子遗传学
- 酵母遗传学 酵母遗传学
背景情况:
- 突变模式受到选择和遗传漂移的影响,但它们的相对影响仍然不清楚.
- 单体细胞 (Saccharomyces cerevisiae) 的突变率高于双体细胞,可能是由于对这种细胞类型的作用有限的选择.
- 随机基因组的突变发生在迟复制区域,这表明涉及易发生错误的转化合成 (TLS) 修复.
研究的目的:
- 调查 haploids 优先使用 TLS 是否解释 haploid 和 diploid 酵母之间的全基因组突变模式差异.
- 确定 *REV1* 基因在酵母细胞类型之间的差异突变率中的作用.
主要方法:
- 突变积累实验在平分体和二分体 *Saccharomyces cerevisiae* 中进行.
- 对于启动TLS至关重要的*REV1*基因在两种细胞类型 (*rev1*Δ菌株) 中都被删除.
- 估计了单核酸突变率,并比较了野生型和*rev1*Δ单核酸和双核酸菌株.
主要成果:
- 野生类型的双胞胎酵母与野生类型的双胞胎酵母相比,单核酸突变率高出50%.
- 删除 *REV1* 消除了这种差异,导致单 haploid 和双 haploid *rev1* Δ 菌株的突变率趋同.
- 发现 *REV1* 基因在两种酵母细胞类型中对线粒体基因组维护至关重要.
结论:
- 转化合成 (TLS) 的突变性影响在平分类酵母中显著更强,可能是由于选择机会有限.
- 对TLS的差异依赖有助于在平分类酵母和二分类酵母之间观察到不同的全基因组突变模式.
- *REV1* 在*Saccharomyces cerevisiae**中,在维持核和线粒体基因组完整性方面发挥着重要作用.
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