Supplementary Table S2_v1_0_20230226_13.xlsx from Domestication affects sex-biased gene expression evolution in the duck

Genes with sex-biased expression are thought to underlie sexually dimorphic phenotypes and are therefore subject to different selection pressures in males and females. Many authors have proposed that sexual conflict leads to the evolution of sex-biased expression, which allows males and females to reach separate phenotypic and fitness optima. The selection pressures associated with domestication may cause changes in population architectures and mating systems, which in turn can alter their direction and strength. We compared sex-biased expression and genetic signatures in wild and domestic ducks (<i>Anas platyrhynchos</i>), and observed changes of sexual selection and identified the genomic divergence affected by selection forces. The extent of sex-biased expression in both sexes is positively correlated with the level of both d<i>_N</i>/d<i>_S</i> and nucleotide diversity. This observed changing pattern may mainly be owing to relaxed genetic constraints. We also demonstrate a clear link between domestication and sex-biased evolutionary rate in a comparative framework. Decreased polymorphism and evolutionary rate in domesticated populations generally matched life-history phenotypes known to experience artificial selection. Taken together, our work suggests the important implications of domestication in sex-biased evolution and the roles of artificial selection and sexual selection for shaping the diversity and evolutionary rate of the genome.

具有性别偏向性表达的基因被认为是性二态表型的分子基础，因此在雄性与雌性个体中面临截然不同的选择压力。诸多研究者指出，性冲突会驱动性别偏向性表达的演化，使雄性和雌性得以分别达到各自最优的表型状态与适合度水平。与驯化过程相关的选择压力，可能会改变种群结构与交配系统，进而改变选择作用的方向与强度。本研究对比了野生与家养绿头鸭（*Anas platyrhynchos*）的性别偏向性表达特征与遗传特征，观测到性选择的演化变化，并鉴定出受选择力量影响的基因组分化区域。两性的性别偏向性表达程度均与d_N/d_S（非同义替换率与同义替换率的比值）以及核苷酸多态性水平呈显著正相关。这一观测到的变化模式主要源于遗传约束的松弛。本研究还在比较研究框架下，明确证实了驯化与性别偏向性演化速率之间存在紧密关联。家养种群中核苷酸多态性与演化速率的降低，总体上与已知经历人工选择的生活史表型特征相契合。综上，本研究结果表明驯化在性别偏向性演化过程中具有重要意义，同时阐明了人工选择与性选择在塑造基因组多样性及演化速率方面的关键作用。