Which variables determine the constraints on gene sequence evolution is one of the most central questions in molecular evolution. In the fission yeast Schizosaccharomyces pombe, an important model organism, the variables influencing the rate of sequence evolution have yet to be determined. Previous studies in other single celled organisms have generally found gene expression levels to be most significant, with numerous other variables such as gene length and functional importance identified as having a smaller impact. Using publicly available data, we used partial least squares regression, principal components regression, and partial correlations to determine the variables most strongly associated with sequence evolution constraints. We identify centrality in the protein–protein interactions network, amino acid composition, and cellular location as the most important determinants of sequence conservation. However, each factor only explains a small amount of variance, and there are numerous variables having a significant or heterogeneous influence. Our models explain more than half of the variance in dN, raising the possibility that future refined models could quantify the role of stochastics in evolutionary rate variation.

哪些变量决定了基因序列进化的约束是分子进化中最核心的问题之一。在裂殖酵母粟酒裂殖酵母中，一个重要的模式生物，影响序列进化速率的变量尚未确定。先前对其他单细胞生物的研究通常发现基因表达水平最为重要，而许多其他变量，如基因长度和功能重要性被确定为具有较小的影响。使用公开可用的数据，我们使用偏最小二乘回归、主成分回归和偏相关来确定与序列进化约束最密切相关的变量。我们将蛋白质-蛋白质相互作用网络、氨基酸组成和细胞位置的中心性确定为序列保守性的最重要决定因素。然而，每个因素只能解释少量的方差，并且有许多变量具有显着或异质的影响。我们的模型解释了 dN 中一半以上的方差，提高了未来改进模型可以量化随机变量在进化速率变化中的作用的可能性。