Theoretically, paralogous genes generated through whole genome duplications should share identical expression levels due to their identical sequences and chromatin environments. However, functional divergences and expression differences have arisen due to selective pressures throughout evolution. A comprehensive investigation of the expression patterns of paralogous gene pairs in response to various stresses and a study of correlations between the expression levels and sequence divergences of the paralogs are needed. In this study, we analyzed the expression patterns of paralogous genes under different types of stress and investigated the correlations between the expression levels and sequence divergences of the paralogs. We analyzed the differential expression patterns of the paralogs under four different types of stress (drought, cold, infection, and herbivory) and classified them into three main types according to their expression patterns. We then further analyzed the differential expression patterns under various degrees of stress and constructed corresponding co-expression networks of differentially expressed paralogs and transcription factors. Finally, we investigated the correlations between the expression levels and sequence divergences of the paralogs and identified positive correlations between expression level and sequence divergence. With regard to sequence divergence, we identified correlations between selective pressures and phylogenetic relationships. These results shed light on differential expression patterns of paralogs in response to environmental stresses and are helpful for understanding the relationships between expression levels and sequences divergences.

中文翻译：

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旁系同源物响应压力的差异表达模式表明表达和序列差异。

从理论上讲，通过全基因组复制产生的同源基因应具有相同的表达水平，这是由于它们的序列和染色质环境相同。但是，由于整个进化过程中的选择性压力，导致了功能差异和表达差异。需要全面研究旁系同源基因对响应各种压力的表达模式，并研究旁系同源物的表达水平和序列差异之间的相关性。在这项研究中，我们分析了不同压力下旁系同源基因的表达模式，并研究了旁系同源基因的表达水平和序列差异之间的相关性。我们分析了四种不同压力（干旱，寒冷，感染，和草食动物），并根据它们的表达方式将其分为三种主要类型。然后，我们进一步分析了在不同压力下的差异表达模式，并构建了差异表达的旁系同源物和转录因子的相应共表达网络。最后，我们研究了旁系同源物的表达水平与序列差异之间的相关性，并确定了表达水平与序列差异之间的正相关性。关于序列差异，我们确定了选择性压力和系统发育关系之间的相关性。这些结果阐明了旁系同源物响应环境胁迫的差异表达模式，并且有助于理解表达水平和序列差异之间的关系。