The evolution of genomes at large

实现对基因组大规模特征的详细了解是21世纪生物科学的首要目标之一。尽管全基因组测序的迅速兴起理所当然地在科学界内外引起了相当大的关注，但对特定DNA序列的分析和在模式生物中寻找蛋白质编码基因只代表了比较基因组学的一个方面。尽管基因组学的其他领域最近取得了巨大的进展，但对基因组的一些最基本属性的变化，如大小和组成，仍然难以解释。例如，即使经过半个多世纪的持续研究，为什么不同动物基因组中包含的DNA数量(即基因组大小)的范围超过3300倍，这仍然是一个悬而未决的谜团。这里概述的研究计划试图通过直接处理长期存在的基因组大小变化之谜来推进我们对大规模基因组进化的理解。具体地说，这里提出的研究将从几个主要方面阐明这一重要问题：1)通过提高从不同动物分类群中获得基因组大小数据的效率和准确性；2)通过填补当前哺乳动物、鸟类和鱼类基因组大小数据库中的一些主要空白，3)通过对昆虫基因组大小进行第一次大规模调查，以及4)通过测试一些关于基因组大小与细胞大小、新陈代谢和发育等特征之间关系的具体假设。*通过与新兴的生物多样性倡议和新的DNA量化技术的联系，我的实验室将准备产生前所未有的规模的基因组大小数据。*从更大的角度来看，这些重要的初步研究将代表着我将努力在安大略省新的生物多样性研究所内培育的一个更大的“基因组多样性”计划的种子。总的来说，除了回答有关基因组进化的一些最基本的问题外，该计划还将为在一系列生物学学科工作的生物学家提供具有实际意义的数据。

Achieving a detailed understanding of the large-scale features of genomes represents one of the premier objectives of twenty-first century biological science.  Though the rapid rise of complete genome sequencing has justifiably garnered considerable attention both within and outside the scientific community, analyses of specific DNA sequences and the search for protein-coding genes in model organisms represent only one aspect of "comparative genomics".   Despite tremendous recent progress in other areas of genomics, explanations for variation in some of the most basic properties of genomes, such as size and composition, remain elusive.  For example, even after more than half a century of continuous study, it remains an unresolved puzzle why the amount of DNA contained within different animal genomes (i.e., genome size) ranges more 3,300-fold.  The research program outlined here seeks to advance our understanding of large-scale genome evolution by dealing directly with the long-standing enigma of genome size variation.  Specifically, the research proposed here will shed light on this important issue in several major ways: 1) by improving the efficiency and accuracy by which genome size data can be obtained from a diverse array of animal taxa, 2) by filling some major gaps in the current genome size datasets for mammals, birds, and fishes, 3) by performing the first large-scale survey of genome sizes in insects, and 4) by testing some specific hypotheses about the relationships between genome size and such features as cell size, metabolism, and development.  Through linkages with emerging biodiversity initiatives and with use of novel DNA quantification technology, my lab will be poised to generate genome size data on an unprecedented scale.  In larger terms, these important initial studies will represent the seed of a much larger program in "genomic diversity" that I will strive to cultivate within the new Biodiversity Institute of Ontario.  Overall, this program will provide data of practical significance to biologists working in a range of biological disciplines, in addition to answering some of the most fundamental questions about the evolution of genomes at large.