英国雷丁大学论文代写:核心基因
Keywords:雷丁大学论文代写
首先,作者表明,只有17%的核心基因在枯草芽孢杆菌后随链,这是类似于以前的研究。研究突变的基因是否与他们的取向有关,变异率计算的核心基因。在所有基因以及核心基因的同义突变的引领和滞后链是相似的,而非同义的速度滞后链明显高于前导链。之后,保罗等人认为正面replication-transcription冲突可能负责变异率之间的差异在前导链和滞后链。为了证明这一点,他们做了三个实验。首先,记录长度的领导,后随链基因进行了分析。基因上的滞后链往往是短的。和更少的基因,编码的蛋白质有超过200个氨基酸,在滞后链而不是前导链。因此,基因后随链短可能避免replication-transcription正面相撞。其次,作者发现非同义变异率之间的正相关和基因长度或表达水平。综上所述,replication-transcription冲突可能会导致利率的增加诱变后随链。第三,回归分析来说明执行实验是否增加突变率后随链上的基因实际上是由于replication-transcription冲突。保罗等人工程师菌株,集成的一个副本组氨酸合成酶基因的上游和下游地区都拥有一个IPTG诱导启动子。当IPTG诱导的转录导致诱变率增加,但突变的速度比co-orientation更多正面取向会显著上升。因此,正面replication-transcription冲突可能会导致增加的突变。
英国雷丁大学论文代写:核心基因
After that, Paul et al. presume that head-on replication-transcription conflict may be responsible for the differences between mutation rates on leading strand and lagging strand. To prove it, they have done three experiments. First, transcript lengths of leading- and lagging-strand genes are analyzed. Genes on the lagging strand tend to be shorter. And much fewer genes, encoding protein with more than 200 amino acids, are on the lagging strand than on the leading strand. Thus, genes on the lagging strand are shorter probably to avoid head-on replication-transcription collision. Second, the authors find that a positive correlation between non-synonymous mutation rates and gene length or expression level. Taken together, replication-transcription conflicts may lead to the increased rates of mutagenesis on the lagging strand. Third, reversion assays are executed to illustrate experimentally whether increased mutation rates of genes on the lagging strand are really due to replication-transcription conflicts. Paul et al. engineer strains, integrated a copy of the histidine synthetase gene whose upstream and downstream regions both owns an IPTG inducible promoter. When inducible by IPTG, transcription results in increased rates of mutagenesis, but mutations rate of head-on orientation increases significantly more than that of co-orientation. Therefore, head-on replication–transcription conflicts can cause increase of mutagenesis.
