Transcrptional profiles of Cryptococcous neoformans Gsb1 at non-stress and oxidative stress conditions

Purpose: To identify the downstream genes whose expression levels are affected by the deletion of gsb1 under non-stress and oxidative stress conditions, we compared the RNA-seq based transcriptional profiles of wild-type and gsb1 cells. Methods: mRNA profiles of cells grown at non-stress and oxidative stress conditions were generated by RNA-seq using Illumina GAIIx. The sequence reads that passed quality filters were mapped to reference genome and the normalized RPKM values were calculated by CLC Genomics Workbench. Results: RNA-Seq analysis during normal growth revealed increased expression of a number of genes involved in mitochondrial respiration and cell cycle, but decreased expression of several genes involved in the mating-responsive MAPK signaling pathway. Moreover, RNA-Seq analysis under oxidative stress revealed that several genes involved in ROS defense, cell wall remodeling, and protein glycosylation were highly induced in the wild-type strain but not in gsb1. Conclusions: This study proposed that Gsb1 is a key transcriptional regulator modulating growth, anti-stress responses, differentiation, and virulence in C. neoformans. Overall design: mRNA profiles of cells grown at non-stress and oxidative stress conditions were generated by RNA-seq using Illumina.

研究目的：为鉴定非胁迫与氧化胁迫条件下gsb1基因缺失所影响的下游基因表达水平，本研究通过比较野生型菌株与gsb1缺失菌株基于RNA测序（RNA-seq）的转录谱展开分析。
研究方法：采用Illumina GAIIx平台进行RNA测序，获取非胁迫及氧化胁迫环境下培养细胞的mRNA表达谱。将通过质量过滤的测序序列比对至参考基因组，并通过CLC Genomics Workbench计算标准化的每百万映射reads每千碱基reads计数（RPKM）。
研究结果：正常生长条件下的RNA-seq分析显示，多个参与线粒体呼吸与细胞周期调控的基因表达上调，而若干参与交配响应型丝裂原活化蛋白激酶（MAPK）信号通路的基因表达下调。此外，氧化胁迫条件下的RNA-seq分析表明，野生型菌株中参与活性氧（ROS）防御、细胞壁重塑与蛋白质糖基化的若干基因被显著诱导，但该诱导现象在gsb1缺失菌株中未出现。
研究结论：本研究提出Gsb1是新型隐球菌（C. neoformans）中调控生长、抗胁迫应答、分化与致病力的关键转录调控因子。
整体实验设计：采用Illumina平台进行RNA测序，获取非胁迫与氧化胁迫环境下培养细胞的mRNA表达谱。