The evolution of marine phytoplankton under extreme polar conditions

极端极地条件下海洋浮游植物的演化

• 批准号: 2237694
• 金额: --
• 依托单位: University of East Anglia
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2237694
• 关键词: evolution; marine; phytoplankton; under; extreme

Marine phytoplankton has a huge biodiversity and biomass, yet despite its biological importance, these species remain woefully understudied. We were the first to sequence the genome of a polar phytoplankton species, and what we discovered shocked the scientific community. Firstly, we found that the genome of this species is fundamentally different from the genomes of other "model" species. We detected an overwhelming signature of positive selection, and discovered that a large proportion of its genes is evolving by natural selection, rather than by genetic drift. This finding flies in the face of the most fundamental theory of evolution, Kimura's (1968) Neutral Theory. It thus appears that the theory developed based on studies of classical model species (e.g. Drosophila) might be inadequate to understand the evolution of marine phytoplankton. Secondly, we discovered that this marine phytoplankton species employs its genetic variation in a unique manner which offers a significant evolutionary advantage; it can express alternative sets of alleles depending on the environment the organism encounters (Mock et al. 2017. Nature 541, 536-540).

海洋浮游植物具有巨大的生物多样性和生物量，然而，尽管其生物重要性，这些物种仍然严重不足。我们是第一个对极地浮游植物物种的基因组进行测序的人，我们的发现震惊了科学界。首先，我们发现这个物种的基因组与其他“模式”物种的基因组有着根本的不同。我们检测到了正向选择的压倒性特征，并发现其大部分基因是通过自然选择而不是遗传漂变进化的。这一发现与最基本的进化理论--木村（Kimura）的中性理论（Neutral Theory）背道而驰。因此，基于对经典模式物种（如果蝇）的研究而发展起来的理论似乎不足以理解海洋浮游植物的进化。其次，我们发现这种海洋浮游植物物种以独特的方式利用其遗传变异，这提供了显着的进化优势;它可以根据生物体遇到的环境表达替代的等位基因组（Mock et al. 2017。Nature 541，536-540）。