Abstract:
Maternal genes have a pivotal role in regulating metazoan early development. As such their functions have been extensively studied since the dawn of developmental biology. The temporal and spatial dynamics of their transcripts have been thoroughly described in model organisms and their functions have been undergoing heavy investigations. Yet, less is known about the evolutionary changes shaping their presence within diverse oocytes. Due to their unique maternal inheritance pattern, a high degree is predicted to be present when it comes to their expression. Insofar only limited and conflicting results have emerged around it. Here, we set out to elucidate which evolutionary changes could be detected in the maternal gene expression patterns using phylogenetic comparative methods on RNAseq data from 43 species. Using normalized gene expression values and fold change information throughout early development we set out to find the best-fitting evolutionary model. Through modeling, we find evidence supporting both the high degree of divergence and constraint on gene expression values, together with their temporal dynamics. Furthermore, we find that maternal gene expression alone can be used to explain the reproductive modes of different species. Together, these results suggest a highly dynamic evolutionary landscape of maternal gene expression. We also propose a possible functional dichotomy of maternal genes which is influenced by the reproductive strategy undertaken by examined species.
摘要:
背景:母系基因在调节后生动物早期发育中具有关键作用。因此,自发育生物学诞生以来,它们的功能已得到广泛研究。已在模型生物中彻底描述了其转录本的时间和空间动力学,并且其功能正在进行大量研究。然而,对进化变化形成它们在不同卵母细胞中的存在知之甚少。由于其独特的母系遗传模式,当谈到他们的表达时,预计会有很高的程度。到目前为止,围绕它的结果有限且相互矛盾。
结果:在这里,我们着手阐明在来自43个物种的RNAseq数据上使用系统发育比较方法可以在母体基因表达模式中检测到哪些进化变化。在整个早期开发过程中使用归一化基因表达值和倍数变化信息,我们着手寻找最佳拟合进化模型。通过建模,我们发现了支持基因表达值高度分歧和约束的证据,以及它们的时间动态。此外,我们发现,单独的母本基因表达可以用来解释不同物种的生殖模式。
结论:一起,这些结果提示了母体基因表达的高度动态进化景观。我们还提出了母本基因的一种可能的功能二分法,该基因受被检查物种采取的生殖策略的影响。