Causes and consequences of genome size diversity in animals

动物基因组大小多样性的原因和后果

• 批准号: RGPIN-2016-03964
• 负责人: Gregory, Ryan
• 金额: $ 2.33万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=632046
• 关键词: Causes; consequences; genome; size; diversity

The genomes of animals range >7,000-fold in size, an observation that has remained a central puzzle in genetics for more than 65 years. My lab is at the forefront of research that seeks to catalogue and explain the patterns of genome size diversity across animals. The next 5 years of research in my lab will focus on three complementary areas: 1) Patterns and correlates of genome size diversity across species in several target groups; 2) Tissue-specific modulations of DNA content (endopolyploidy), and 3) Mechanisms of genome size change and transposable element evolution. In the first set of studies, my students and I will use our considerable expertise to greatly expand our knowledge of genome size diversity in molluscs and arachnids, and will provide the very first study of genome sizes in lichens. This will include both broad, discovery-based explorations and focused testing of hypotheses using phylogenetically-informed comparative methods. In the second series of projects, we will investigate the biological significance of endopolyploidy, in which the genome is replicated up to thousands of times within specific tissues. Endopolyploidy appears to be a very widespread phenomenon, but its overall significance remains poorly understood. We will examine the patterns of endopolyploidy in three major case studies from arthropods in order to test ideas regarding the biological relevance of this phenomenon: 1) Silk and venom glands of spiders with varying feeding strategies (e.g., web-weaving vs. active hunting); 2) Nurse cells (trophocytes) found in the ovaries of some insects, which provision the developing eggs with nutrients; and 3) Guts and Malpighian tubules in insects with different diets. Finally, in the third set of projects, we will continue to expand our investigations of the mechanistic bases of genome size change, in particular the role played by transposable elements in affecting total genome size. This area of research uses bioinformatics analyses and survey sequencing using next-generation sequencing technology to determine how transposable element abundance, diversity, and activity are related to genome size variability. The research proposed here will provide opportunities for the training of a number of MSc, PhD, and undergraduate research students, and is expected to be of high impact as it addresses questions of fundamental importance for our understanding of genome form, function, and evolution.

动物的基因组大小超过7,000倍，这一观察结果在65年多的时间里一直是遗传学的核心难题。我的实验室处于研究的最前沿，试图对动物的基因组大小多样性模式进行分类和解释。我实验室未来5年的研究将集中在三个互补领域：1）几个目标群体中物种间基因组大小多样性的模式和相关性; 2）DNA含量的组织特异性调节（内多倍性）; 3）基因组大小变化和转座因子进化的机制。在第一组研究中，我和我的学生将利用我们相当丰富的专业知识，极大地扩展我们对软体动物和蛛形纲动物基因组大小多样性的知识，并将首次对地衣基因组大小进行研究。这将包括广泛的、基于发现的探索和使用遗传学信息的比较方法对假设进行的集中测试。在第二系列项目中，我们将研究内多倍性的生物学意义，其中基因组在特定组织内复制高达数千次。内多倍性似乎是一个非常普遍的现象，但其整体意义仍然知之甚少。我们将在来自节肢动物的三个主要案例研究中研究内多倍性的模式，以测试关于这种现象的生物学相关性的想法：1）具有不同进食策略的蜘蛛的丝和毒腺（例如，2）在一些昆虫的卵巢中发现的营养细胞（滋养细胞），其为发育中的卵提供营养;和3）具有不同饮食的昆虫的肠道和马氏管。最后，在第三组项目中，我们将继续扩大我们对基因组大小变化的机制基础的研究，特别是转座因子在影响总基因组大小中所起的作用。该研究领域使用生物信息学分析和使用下一代测序技术的调查测序，以确定转座因子丰度，多样性和活性如何与基因组大小变异性相关。这里提出的研究将为一些硕士，博士和本科研究生的培训提供机会，预计将产生很大的影响，因为它解决了我们对基因组形式，功能和进化的理解具有根本重要性的问题。