Intra- and inter-specific variations of gene expression levels in yeast are largely neutral

It is commonly, although not universally, accepted that most intra- and inter-specific genome sequence variations are more or less neutral, whereas a large fraction of organism-level phenotypic variations are adaptive. Gene expression levels are molecular phenotypes that bridge the gap between genotypes and corresponding organism-level phenotypes. Yet, it is unknown whether natural variations in gene expression levels are mostly neutral or adaptive. Here we address this fundamental question by genome-wide profiling and comparison of gene expression levels in nine yeast strains belonging to three closely related Saccharomyces species and originating from five different ecological environments.尽管并非普适性共识，但学界普遍认为，大多数种内与种间的基因组序列变异或多或少呈中性特征，而绝大多数生物体层面的表型变异则具有适应性。基因表达水平属于分子表型，架起了基因型与对应生物体层面表型之间的桥梁。然而，目前学界仍不清楚基因表达水平的自然变异究竟以中性为主还是以适应性为主。本研究针对来自5种不同生态环境、隶属于3个近缘酿酒酵母（Saccharomyces）属物种的9株酵母菌，开展了全基因组基因表达谱分析与比较，以此解答这一基础性科学问题。