Heritable gene expression differences between apomictic clone members in Taraxacum officinale: insights into early stages of evolutionary divergence in asexual plants

Background: Asexual reproduction has the potential to enhance deleterious mutation accumulation and to constrain adaptive evolution. One source of mutations that can be especially relevant in recent asexuals is activity of transposable elements (TEs), which may have experienced selection for high transposition rates in sexual ancestor populations. Predictions of genomic divergence under asexual reproduction therefore likely include a large contribution of transposable elements but limited adaptive divergence. For plants empirical insight into genome divergence under asexual reproduction remains limited. Here, we characterize expression divergence between clone members of a single apomictic lineage of the common dandelion (Taraxacum officinale) to contribute to our knowledge of genome evolution under asexuality. Results: Using RNA-Seq, we show that about one third of heritable divergence within the apomictic lineage is driven by TEs and TE-related gene activity. In addition, we identify ...背景：无性生殖可能会加剧有害突变的积累，并限制适应性进化。对于新近演化出无性生殖的类群而言，转座因子（transposable elements, TEs）的活性是一类尤为关键的突变来源——这类因子在其有性祖先种群中，可能曾经历过高转座速率的正向选择。据此，无性生殖状态下的基因组分化预测中，转座因子往往占据重要贡献份额，而适应性分化则相对受限。目前针对植物类群的无性生殖下基因组分化的实证研究仍较为匮乏。本研究以普通蒲公英（Taraxacum officinale）的单个无融合生殖谱系的克隆个体为研究对象，解析其表达分化特征，以期为无性生殖模式下的基因组演化研究补充实证认知。 结果：本研究通过转录组测序（RNA-Seq）分析表明，该无融合生殖谱系内约三分之一的可遗传分化由转座因子及转座因子相关基因的活性所驱动。此外，本研究还鉴定出……