The role of mitotic recombination in genome evolution of polar phytoplankton

有丝分裂重组在极地浮游植物基因组进化中的作用

• 批准号: 2749679
• 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: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2749679
• 关键词: role; mitotic; recombination; genome; evolution

Despite the harsh environmental conditions in polar oceans, these ecosystems harbour significant biodiversity. How this biodiversity underpinning productive ecosystems and resources for novel products used in biotechnology, agriculture and medicine has evolved largely remains unknown. One reason for this knowledge gap is that we only know little as to how mutation and recombination as major evolutionary forces shape polar organisms and therefore their genes enabling them to thrive under the harsh polar growth conditions. Arguably, most of the genetic variation driving biological diversity stems from mutations. As their rate is temperature dependent with increasing. Mutation rates at the extreme ends, it suggests that polar organisms likely need to cope with higher mutational loads. Polar diatom genomes have provided evidence that these microalgae benefit from elevated mutation rates, generating genetic diversity to respond to fast-changing environmental conditions (e.g. freezing and melting) in the absence of sexual recombination. However, direct experimental evidence is missing. The project will investigate if DNA damage is enhanced in a polar diatom vs a non-polar counterpart and how mitotic recombination contributes to the genetic variation that is adaptive. Using fluorescence-based assays in combination with genome re-sequencing to quantify DNA damage after cold and heat stress in a polar and a nonpolar diatom species. How DNA-repair induced mitotic recombination contributes to genetic variation and differences between both diatom species will be tested using two core DNA-repair enzymes (BRCA2, KU70) andrevealing subsequent effects on DNA damage and fitness (Growth rates) under temperature stress. Thus, data from this project will lay the foundation for how the extreme polar environment shapes the evolution of genes and genomes in polar phytoplankton underpinning productive food webs and resources for novel enzymes used in biotechnology.

尽管极地海洋的环境条件恶劣，但这些生态系统仍拥有重要的生物多样性。这种生物多样性如何支撑生物技术、农业和医学中使用的新产品的生产性生态系统和资源，在很大程度上仍然未知。造成这种知识差距的原因之一是，我们对突变和重组作为主要进化力量如何塑造极地生物以及它们的基因如何使它们能够在恶劣的极地生长条件下繁衍生息知之甚少。可以说，驱动生物多样性的大部分遗传变异都源于突变。因为它们的速率随温度的增加而变化。突变率处于极端，这表明极地生物可能需要应对更高的突变负荷。极地硅藻基因组提供的证据表明，这些微藻受益于突变率的升高，产生遗传多样性，以在没有性重组的情况下应对快速变化的环境条件（例如冰冻和融化）。然而，缺乏直接的实验证据。该项目将研究极性硅藻与非极性硅藻相比 DNA 损伤是否增强，以及有丝分裂重组如何促进适应性遗传变异。使用基于荧光的检测结合基因组重测序来量化极性和非极性硅藻物种在冷热应激后的 DNA 损伤。 DNA 修复诱导的有丝分裂重组如何导致遗传变异以及两种硅藻物种之间的差异将使用两种核心 DNA 修复酶（BRCA2、KU70）进行测试，并揭示温度胁迫下对 DNA 损伤和适应性（生长率）的后续影响。因此，该项目的数据将为极端极地环境如何塑造极地浮游植物基因和基因组的进化奠定基础，而极地浮游植物支撑着生产性食物网和生物技术中使用的新型酶的资源。