【摘要】 1987年,由Selker等在粗糙脉孢菌中首次发现重复序列诱导点突变(repeat-induced point mutation,RIP).在重复序列诱导点突变过程中,搜寻前减数分裂组织单倍体核中DNA的重复序列,然后发生众多的碱基C到T的突变,产生富碱基T+A片段,从而使重复序列中的G-C碱基对发生转换突变成为A-T碱基对.此外,发生RIP的序列多集中在着丝粒区域,主要是转座子甲基化后的遗迹.移动转座子是真核生物基因组进化的主要驱动力.对于真菌,重复序列诱导点突变(RIP)在减数分裂过程中通过突变多拷贝DNA,能最大限度地减少转座子的影响,因此对RIP的研究在一定程度上能有助于了解基因组进化的真谛.综述了重复序列诱导点突变的产生机制,以及真菌中重复序列诱导点突变的研究进展.更多还原

【Abstract】 Repeat- induced point mutations( RIP) was discovered in Neurospora crassa in 1987 by Selker.RIP searches for sequence duplications in haploid nuclei of premeiotic tissue and then litters them with numerous C to T mutations. T + A rich fragments so that the G- C pairs in duplications can be mutated to A- T. In addition,RIP’s sequences,which are concentrated in centromeric regions,and are predominantly relics of transposons,are left methylated. Mobile transposable elements are among the primary drivers of the evolution of eukaryotic genomes.For fungi,repeat- induced point mutation( RIP) silencing minimizes deleterious effects of transposons by mutating multicopy DNA during meiosis. To explore the impact of RIP- mutated transposons is conducive to generate evolutionary inferences for phylogenetic and population genetic analyses. The paper has reviewed the mechanism of RIP and the progress of RIP in fungi.更多还原