在Cryptococcus neoformans中失去RNA干扰后,不同的进化轨迹
Jun Huang1, Connor J Larmore1, Shelby J Priest1
1Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710.
概括
像Cryptococcus neoformans这样的微生物中RNA干扰 (RNAi) 的损失可以实现快速适应. 这项研究揭示了RNAi损失是常见的,可以通过转位子活性导致高突变和耐药性,或允许没有它的生存.
科学领域:
- 微生物学 微生物学
- 进化生物学 进化生物学
- 遗传学 是一个遗传学.
背景情况:
- 超级突变虽然在多细胞生物中有害,但可以推动微生物的适应.
- 之前的工作确定了超变异的Cryptococcus neoformans菌株,具有与逆转移素Cnl1相关的耐药性,由ZNF3基因突变和高转移素负载引起.
- RNA干扰 (RNAi) 对基因组稳定性和调节转位子至关重要.
研究的目的:
- 研究在Cryptococcus neoformans中RNA干扰 (RNAi) 损失后的适应机制和进化轨迹.
- 在大型孤立集合中识别和表征RNAi功能丧失 (LOF) 突变.
- 确定单独或与转子子积累相结合的RNAi损失是否驱动超变异.
主要方法:
- 开发了两个生物信息管道来检测387个C. neoformans分离物中的RNAi LOF突变.
- 引入已识别的RNAi LOF突变到非高突变菌株中,以评估它们对突变率的影响.
- 进行RNAi损失菌株和基因交叉的体外传递,以研究高突变演变.
主要成果:
- 在387例中,在7例中确定了RNAi LOF突变 (约. 1.8%) 的C. neoformans分离物;有几种不是超级突变物.
- 在将RNAi LOF突变实验性地引入高转子子负荷菌株中,诱导了一种超变异体表型.
- 实验室传递显示了Cryptococcus deneoformans的高突变,但不是C. neoformans,而基因交叉产生了超突变后代,具有Cnl1和KDZ1转位子的高负担.
结论:
- RNAi损失是C. neoformans中经常发生的事件,提供了不同的进化途径.
- 丢失RNAi可以使微生物易于过度突变和快速适应,特别是当与转子子活动相结合时.
- 这些发现凸显了RNAi损失在微生物进化中的双重作用:通过高突变实现适应或通过其他机制促进生存.
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