Comparison of yeast (Saccharomyces cerevisiae) strain with histone H4 R45 mutated to H with wild type yeast strain WY139. Saccharomyces cerevisiae

Total RNA samples from three replicate cultures of wild type and mutant yeast strains was isolated and expression profile done using Affymetrix arrays. Comparsion between the samples indicate how mutation in a single amino acid residue in histone H4 (H4R45H) affects gene expression in yeast. Such a mutation in histone H4 is known to generate a specific class of mutants called SWI/SNF independent (SIN) mutants, and the mutants were identified by their ability to carry out transcription in the absence of yeast chromatin remodeling complex SWI/SNF. SIN mutations are known to affect higher order chromatin structure and the comparative expression profile would help identification of genes which get affected by such altered chromatin landscape. Keywords: mutant analysis Overall design: Comparison of genes whose mRNA levels are affected in histone H4R45H mutant yeast strains compared to wild type yeast strain WY139. This comparison reveals how subtle change in a single amino acid residue in core domain of histone H4 affects gene expression profile in yeast.

从野生型与突变型酵母菌株的三份重复培养物中提取总RNA样本，并通过Affymetrix芯片（Affymetrix arrays）完成表达谱分析。通过样本间的比较分析，可明确组蛋白H4（histone H4）中单个氨基酸残基突变（H4R45H）对酵母基因表达的影响。已知组蛋白H4的这类突变可诱导产生一类被称为SWI/SNF非依赖型（SWI/SNF independent, SIN）的突变体，此类突变体凭借在缺失酵母染色质重塑复合物SWI/SNF的情况下仍能完成转录的特性被鉴定得到。现有研究证实SIN突变会影响染色质的高级结构，本研究的比较表达谱分析将有助于鉴定受此类染色质状态改变影响的基因。关键词：突变体分析。实验设计：对比组蛋白H4R45H突变型酵母菌株与野生型酵母菌株WY139的mRNA水平差异基因，以揭示组蛋白H4核心结构域内单个氨基酸残基的微小变化如何调控酵母的基因表达谱。