在最新一期的开放存取的《公共科学图书馆·生物学》杂志上,美国、英国和瑞典的研究人员公布了老鼠的全基因组测序图。老鼠成为继人类之后第二个完成全基因组测序的哺乳动物。
在对人类和老鼠的基因测序图进行综合性比较后,研究人员发现两者之间的遗传差异要比人们预想的大得多。老鼠基因中有20%是新副本,这些副本是在过去9000万年里演化而来的。人类与老鼠间的大量遗传差异很可能决定着他们的生物学差异。
此项研究成果填补了之前老鼠基因组研究的空白,强化了科学家的能力,使他们能找出最适于人类疾病的老鼠基因,也证明了如何将人类与老鼠共享的生物学特征与某一物种所特有的生物学特征区别开来。研究发现,这些新发现的基因有许多以一种不寻常的速度进行快速演化,这很可能是由于老鼠和其生殖细胞间进行“军备竞赛”所致。
该项计划的领导者、英国牛津大学的克里斯·庞亭教授称,在帮助科学家区分那些在所有哺乳动物中都一样的生物学基础基因,以及那些使人类与老鼠彼此之间具有如此大差异的基因方面,这些新发现极其重要。计划的另一领导者、美国国立卫生研究院生物技术研究中心的戴拿·彻奇也认为,更重要的是,此项发现揭示了许多先前被隐藏着的老鼠生物学秘密。(生物谷Bioon.com)
生物谷推荐原始出处:
PLoS Biol 7(5): e1000112. doi:10.1371/journal.pbio.1000112
Lineage-Specific Biology Revealed by a Finished Genome Assembly of the Mouse
Deanna M. Church1#*, Leo Goodstadt2#*, LaDeana W. Hillier3, Michael C. Zody4,5, Steve Goldstein6, Xinwe She7, Carol J. Bult8, Richa Agarwala1, Joshua L. Cherry1, Michael DiCuccio1, Wratko Hlavina1, Yuri Kapustin1, Peter Meric1, Donna Maglott1, Zo? Birtle2, Ana C. Marques2, Tina Graves3, Shiguo Zhou6, Brian Teague6, Konstantinos Potamousis6, Christopher Churas6, Michael Place9, Jill Herschleb6, Ron Runnheim6, Daniel Forrest6, James Amos-Landgraf10, David C. Schwartz6, Ze Cheng7, Kerstin Lindblad-Toh4,5*, Evan E. Eichler7*, Chris P. Ponting2*, The Mouse Genome Sequencing Consortium?
1 National Center for Biotechnology Information, Bethesda, Maryland, United States of America, 2 MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom, 3 The Genome Center at Washington University, St. Louis, Missouri, United States of America, 4 The Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America, 5 Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden, 6 Laboratory for Molecular and Computational Genomics, University of Wisconsin-Madison, Madison, Wisconsin, United States of America, 7 Department of Genome Sciences and Howard Hughes Medical Institute, University of Washington, Seattle, Washington, United States of America, 8 The Jackson Laboratory, Bar Harbor, Maine, United States of America, 9 Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America, 10 McArdle Laboratory for Cancer Research, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
The mouse (Mus musculus) is the premier animal model for understanding human disease and development. Here we show that a comprehensive understanding of mouse biology is only possible with the availability of a finished, high-quality genome assembly. The finished clone-based assembly of the mouse strain C57BL/6J reported here has over 175,000 fewer gaps and over 139 Mb more of novel sequence, compared with the earlier MGSCv3 draft genome assembly. In a comprehensive analysis of this revised genome sequence, we are now able to define 20,210 protein-coding genes, over a thousand more than predicted in the human genome (19,042 genes). In addition, we identified 439 long, non–protein-coding RNAs with evidence for transcribed orthologs in human. We analyzed the complex and repetitive landscape of 267 Mb of sequence that was missing or misassembled in the previously published assembly, and we provide insights into the reasons for its resistance to sequencing and assembly by whole-genome shotgun approaches. Duplicated regions within newly assembled sequence tend to be of more recent ancestry than duplicates in the published draft, correcting our initial understanding of recent evolution on the mouse lineage. These duplicates appear to be largely composed of sequence regions containing transposable elements and duplicated protein-coding genes; of these, some may be fixed in the mouse population, but at least 40% of segmentally duplicated sequences are copy number variable even among laboratory mouse strains. Mouse lineage-specific regions contain 3,767 genes drawn mainly from rapidly-changing gene families associated with reproductive functions. The finished mouse genome assembly, therefore, greatly improves our understanding of rodent-specific biology and allows the delineation of ancestral biological functions that are shared with human from derived functions that are not.