生物谷报道:人类基因组计划通过测序发现人类大约有3万个基因,而大鼠,小鼠等哺乳动物基因组也被测序完毕,但是面对人们又产生了一个新的问题:如何研究这些基因的功能?复旦大学发育生物学研究所即将发表在Cell上一篇文章揭开这一秘密,该成果已由国际顶级生命科学杂志《细胞》在线发表(http://www.cell.com/content/future),并将刊登在8月12日《细胞》杂志的封面。
要解读这本包罗生老病死等浩瀚奥秘的“天书”,必须寻找到一种工具,能够高效制造大面积基因突变和培育转基因动物。传统的单个基因研究的方法极其缓慢,已难以适应快速发展的基因组学的研究。如今,这个“神奇工具”被中国科研人员发现。上海复旦大学发育生物学研究所的科研人员将一种源于飞蛾的PB(PiggyBac)转座子(Transposon)用于小鼠和人类细胞的基因功能研究,在世界上首次创立了一个高效实用的哺乳动物转座因子系统,为大规模研究哺乳动物基因功能提供了崭新途径。
复旦大学于25日宣布:这一成果被国际一流的生命科学杂志《细胞》(CELL)作为封面文章发表,第一作者丁昇是复旦大学三年级研究生。相关技术已申请国际专利。这个源于飞蛾的PB转座子被赋予了“夸蛾因子”的中国名字,“夸蛾”是古文《愚公移山》中的大力士。
我们知道,转座子是一种可以进入基因组内不同位置的基因载体。科学家利用它们插入基因导致突变以了解基因功能,也利用它们培育转基因生物。麦克林托克(B. McClintock)因首先在玉米中发现转座因子而获得了1983年诺贝尔医学奖。许田博士和吴晓晖博士共同领导的研究小组发产生了一个重要的idea:如果我们在转座子中引入突变,那么这个突变可以被转座子带到基因组的不同地方,从而引起大量的基因突变,产生大量的表型,由于突变的已知性,从而可以利用这些突变直接找到与表型相对应的基因。这是多么美妙的一个idea!由
然而,这有一个巨大障碍,因为在哺乳类动物中几乎找不到天然活性的转座因子!长期以来,为寻找一种对哺乳动物高效、实用的转座因子,世界各国的科学家投入了大量的热情和精力。
复旦科学家们想到一个新的突破方案:与哺乳动物较接近的飞蛾,或果蝇类动物中,转座子是比较明朗,那么能否进行移花接木?
在这一大胆的假设前提下,他们利用飞蛾体内一种常见的转座子PB,经过改造后,作为重要的靶点,将PB转座因子高效插入小鼠基因组,还可以培育转基因小鼠。同时,PB转座因子可在人等哺乳动物的细胞株中高效导入基因并稳定表达,为体细胞遗传学研究和基因表达提供了一个高效、便捷的新系统。《细胞》杂志审稿人评价:“这是里程碑式的发现,将可能在世界范围内改变小鼠遗传学研究,并有用于人类基因治疗的前景 (these are landmark finding with the potential to alter the way mouse genetics is carried out worldwide, and with implications for human gene therapy. )”。
在过去的30多年中,全世界科学家凝聚大量的人力物力,对约10%的哺乳动物基因的功能有所了解,而复旦大学的研究小组用PB转座因子建立了小鼠体内直接突变基因技术,在不到一年内培育出约1%小鼠基因的突变品系,为大规模研究小鼠等哺乳动物基因功能提供了解决方案。运用基因剔除方法,2位研究人员需要用上1年的时间才能分析2个基因的功能;而复旦大学的2位研究人员仅仅用了3个月就研究了70多个基因。
复旦发育生物学研究所由旅美华人学者许田韩珉和庄原共同创立,并得到了教育部、国家自然科学基金和上海市科委的大力支持,也得到美国休斯医学研究院、耶鲁大学、科罗拉多大学和杜克大学的支持和合作。研究所坚持以世界一流学术中心为标准,坚持源头创新,坚持在创新中培养高质量的人才。成立三年半来,全体人员卧薪尝胆,艰苦创业,已把研究所建成发育生物学学科建设和人才培养的基地。论文第一作者丁昇是复旦三年级研究生。 运用PB转座因子研究新方法可以在大范围内快速寻找疾病相关基因,建立多种疾病模型,寻找疾病机理和药物靶点,从而发现、创新治疗手段和药物,也为人类疾病的基因治疗提供了新途径。新方法还可以用于鉴定并研究具有重要生物学功能的基因,并改良经济动物。目前,以PB转座因子技术体系为依托,大规模研究基因功能的小鼠功能基因组计划已经在复旦大学启动。
生物谷专家认为,由于99%的人类基因在小鼠中有同源性,因此,小鼠是研究哺乳动物和人类基因功能的模式生物。这将对人类了解自身、预防和治疗各类疾病产生重要和深远的影响。这一工具将在高通量的功能基因组学研究中产生深远的影响。这种可控的突变方法较传统的ENU突变有明显的可控性和优势,具有极其广阔和应用前景和价值。
同时,生物谷专家也认为,这篇文章的另一层意义也在于中国科学家在2005年,科研水平有全面的突破和发展。仅仅2005年这半年多时间,已有四篇Cell已发表,这一成就是瞩世举目的!生物谷对每一篇文章的发表都做了大量篇幅报道,使更多的读者了解了国内生物学的令人激动的快速发展历程。同时,据生物谷的信息,中科院上海生命科学研究院有一篇Cell文章已投稿,同时国内还有一篇文章也正向Cell投稿,无论如何,2005年都是中国生物学的丰收年和大突破年,可能成为中国生物学的正在崛起的标志性一年!
Sheng Ding, Xiaohui Wu, Gang Li, Min Han, Yuan Zhuang, and Tian Xu. Efficient Transposition of the piggyBac (PB) Transposon in Mammalian Cells and Mice. Cell. Published online Jul. 21, 2005
10.1016/S009286740500707 全文下载[PDF文件]
专题:
[专题]基因组和蛋白质组学
复旦发育生物研究所介绍:
The Institute of Developmental Biology and Molecular Medicine (IDM) is an international biomedical research center. The IDM was funded by Fudan University and was further supported by the Science and Technology Commission of Shanghai Municipality and other funding agencies including the National Natural Science Foundation of China (NSFC). Its laboratory was first opened in Feb. 2002. The IDM pursues broad biomedical researches with a strong effort in the area of developmental biology and molecular mechanisms of human diseases. The IDM offers competitive training programs for highly motivated trainees at both graduate and post graduate levels. As an international academic research center, the IDM promotes scientific and educational exchanges with international scholars. The IDM works closely with the School of Life Science, Fudan University and the Morgan-Tan International Center for Life Sciences in building scientific and academic excellence in China.
DIRECTORS
Tian XU (许田), Ph.D.
-Guest Professor, FDU
-Professor and Vice Chairman, Genetics Department, Yale University
-HHMI Investigator
Min HAN (韩珉), Ph.D.
-Guest Professor, FDU
-Professor, Colorado University
-HHMI Investigator
Yuan ZHUANG (庄原), Ph.D.
-Guest Professor, FDU
-Associate Professor, Duke University
DEPUTY DIRECTOR
Beibei YING (应蓓蓓)
-Director of Graduate Study
-Senior Engineer, FDU
FACULTY MEMBERS
Kejing DENG (邓可京), Ph.D.
-Associate Professor, FDU
Ling SUN (孙璘), Ph.D.
-Associate Professor, FDU
Wufan TAO (陶无凡) , Ph.D.
-Professor, FDU
Xiaohui WU (吴晓晖), Ph.D.
-Associate Professor, FDU
Rener XU (徐人尔), Ph.D.
-Associate Professor, FDU
Xiaodong WANG (王晓东), Ph.D.
-Adjunct Professor, FDU
-Professor, UTSW
-HHMI Investigator
-Member of National Academy of Sciences, USA
Yue XIONG (熊跃), Ph.D.
-Adjunct Professor, FDU
-Professor, University of North Carolina
实际日常在该所工作的有
许田、韩珉、庄原
应蓓蓓、邓可京、孙lin、吴晓晖、徐人尔、陶无凡
可以进行所有常规的小鼠、果蝇、线虫遗传学实验
分子生物学和细胞生物学实验
经费比较充足、仪器比较充分、鼓励学生发挥自己的主观能动性
HHMI成员许田,韩珉能提供全面指导,但基本不包括亲手示范实验
Research Interests
The striking gene conservation between humans and model organisms such as mice, the fruit flies, Drosophila melanogaster, and the nemetode worms, C. elegans, provide a unique opportunity to study gene functions in model organisms. The ability to make crosses between genetically defined strains under controlled environment conditions, to work with large sample sizes, to generate transgenic and knockout animals with mutations in specific genes provide these animal models with powerful genetics. Combining the genetics with the enriched knowledge of the developmental biology in these model organisms, research in these animals has contributed and will still provide the majority of our current knowledge of gene functions and modern biology.
IDM uses multiple model organisms including mouse, fruit fly, and soil worm to study a number of important biological problems related to animal development and human diseases. We are particularly interested in the mechanisms of animal size control, tumorigenesis and metastasis, neural degeneration, and developmental pattern formation. We are also developing new genetic tools in mouse to facilitate functional genomic analysis.
Systematic Analysis of Human Gene Functions in Transgenic Animals
The human genome sequence has been determined. The current challenge is to understand the functions of the genes encoded by the human genome. One of the most powerful ways to reveal gene functions is genetically alternating genes in organisms and observing the phenotypic consequences. Genetic organisms such as mouse, Drosophila melanogaster, and C. elegans, are some of the most powerful models for large-scale genetic manipulations.
We are currently utilizing Drosophila and mouse to perform large-scale functional genomic studies in our institute. The first step of this research is to probe functions of human genes or their homologues by a systematic overexpression screen. The advantages of Drosophila genetics allow us to get the functional clues fairly efficiently. Following the leads from the screen results, genetic and biochemical analyses including generating transgenic, and in some cases gene knock-out mice are being or will be carried out to study the functions of the selected genesc. With this strategy, we have currently finished screening more than 300 human genes, and got dozens of positive results. Several animal models of common human diseases have also been developed.
Cell and Animal Size Regulation
Size is one of the most obvious characters of different species. Recently, many oncogenes and tumor suppressor genes have been found to be involved in cell or organism size control, suggesting that the size regulatory mechanisms also play critical roles in disease processes such as tumorigenesis that require increases in tissue size.
In Drosophila and in mammals, the Insulin/PTEN/TSC signaling pathway and the ras signaling pathway are two major players in cell size regulation. In mammals, these two pathways are known to be involved in various important developmental and disease processes, such as tumorigenesis. It is thus important to identify new factors that act in or with these pathways to regulate cell and animal sizes. Among many candidate genes we have identified through the overexpression screens, one was identified to be a component of the translation machinery. The characterizaition of this gene by a student indicate that it acts downstream of a known size control mechanism in Drosophila.
In addition, we have generated transgenic and knock-out mice for several components of the Insulin/PTEN/TSC as well as other evolutionarily conserved tumor suppressor genes such as lats. These mutants are now being studied to explore the relationship between size control mechanism and tumorigenesis in mammal.
Regulation of Ras Signaling Pathways
The Ras-mediated signaling pathways are involved in many critical cellular events including cell proliferation and differentiation. Multiple model organisms are being used to study certain regulatory aspects of this pathway. We have generated knockout mouse of the sur-8 gene that plays critical role in regulating the activation of Raf kinase by Ras. Preliminary results indicate that the gene is essential for mouse development. We are also cloning and characterizing a previously unknown gene that negatively regulates Ras/MAP kinase signaling activity in C. elegans. Biochemical and mouse genetics work will immediately follow once the worm gene is fully characterized. In addition, chemical genetic method will be explored to discover new means to suppress the activity of this signaling pathway.
Metastasis
Metastasis is the major cause of mortality for cancer patients. Given that the genetic alterations that cause metastasis are usually late events and that multiple genetic alterations occur in late stage cancers, traditional approaches have not been fruitful in identifying genes involved in metastasis. Professor Xu has designed a genetic screen in Drosophila to interrogate the genome for mutations that can cause otherwise noninvasive tumors of the eye disc to exhibit metastatic behaviors, such as the invasion of neighboring or distant tissues. We are systematically interrogating the Drosophila genome to identify genes and mechanisms that either promote or block metastatic behavior. Given that the genes we have identified are evolutionarily conserved, the results of such experiments will lend greater insights into the genetic mechanisms that regulate metastasis in humans. Once the genes are identified through genetic work in Drosophila, characterization of them using mouse genetics will immediately follow.
Neurodegeneration & Transcription Regulation
The expansion of polyglutamine tracks has been identified as the cause for a growing number of progressive neurodegenerative diseases including Huntington\'s disease (HD) and dentatorubral-pallidoluysian atrophy (DRPLA). However, the in vivo functions of Atrophin-1 and Huntingtin, as well as the mechanism of neurodegeneration caused by polyglutamine expansion, is unknown. It has been illustrated by Professor Xu and his students that the Drosophila and human Atrophin homolog functions to repress transcription in Drosophila embryos. To test whether deregulation of transcription dose contribute to the pathogenesis of neurodegeneration in mammal, we have created a transgenic mouse model for DRPLA. Severe neurodegenerative phenotypes develop progressively after the animal reaches its adulthood. Interestingly, this process can be partially suppressed by a compound that involves in transcription regulation. The model could not only help to learn more the role of transcription regulation in neurodegeneration, but also serve as a tool for the development of effective therapies against DRPLA and related diseases.
Mechanisms of Autoimmune Diseases
Lymphocyte development is controlled by a complex array of regulatory molecules including extra-cellular signaling molecules, cell surface receptors, signal transducing kinases, and nuclear transcription factors. Abnormalities in lymphocyte development due to environmental insults or genetic alterations often lead to immune system diseases such as immune deficiency, autoimmune syndromes, or leukemia. We are using the concepts of molecular biology and mouse genetics to investigate the molecular mechanisms lymphocyte development. Professor Zhuang and his student of our institute have recently established a mouse model of Sjögren syndrome, the second most common autoimmune rheumatic disease [Immunity, in press]. This work provides a novel animal model of studying pathogenesis of the disease, the generation of autoimmune cells, and most importantly clues for further clinical prevention, diagnosis and therapy.
Mouse Balancer Chromosome
Although mice share great similarity with human, many useful genetic methods are currently unavailable in mice. One of these is the use of balancer chromosomes. A Balancer chromosome is a particularly useful chromosomal rearrangement that carries multiple inversions, which can effectively suppress homologous recombination within the inverted regions. Originally used in Drosophila melanogaster, balancer chromosomes greatly facilitated the maintenance of recessive lethal mutations, which could play a critical role in large-scale mutagenesis screens in mice. We are currently generating balancer chromosomes of mouse chromosomes 13 and 17. These strains will be extremely helpful for mutagenesis screens that focus on functional annotation of the genes in these two regions, such as the MHC cluster genes on chromosome 17.
Functional Genomics of Model Organisms
Genomics tool has become well established in current biological studies. The sequencing of whole genome has formed the basis for the study of the activity of the whole genome, which is the components of life. Not only when we fully understand how each molecule of life works, but also how they cooperate together, would we be able to know the how life came into being.
This aspect of research at IDM wants to use functional genomics tools (microarray, tissue array, section array, and bioinformatics) combined with other molecular biology tools such as RNAi, etc. to help addressing the questions related to model organism development and mechanism of human diseases.
学生对发育生物研究所的评价:
来源:http://www.bioon.net/dispbbs.asp?boardid=115&id=134852
评价1:首先不得不承认,发育基地真的是一个很锻炼人的地方。别的实验室一般总会有几个师
哥师姐带带什么的,在基地里,你做得就是自己的课题,小到设计一条引物,大到整个实验的设计,方向,基本都要靠自己把握,当然老师会在边上给予一定的帮助。
其次,发育基地的研究学习氛围很好,每周六是labmeeting,大家自己介绍自己的工作进展,大家讨论讨论,一般都是比较激烈的。周二是jourmal club,大家轮着介绍CELL paper(汗,我明天就要第一次jourmal club,还在准备),当然会议都是要求用e文来进行的。平时家的工作时间是9:00--21:00,但是很少看见有同学会这麽准时下班的,不是老板push,我觉得有时候完全是自己在push自己。基地的同学都差不多。
还有一点,我要赞一下基地的设备,我听从yale回来的xx(不记得了,是老板,是同学)说的,这里怎么和yale的一模一样。嘿嘿..... 我的感觉是,为什么连tip都要进口。
最后随便说一下自己的工作吧,最近在做一个有关nuclear anchoring的protein,用drosophila embryo system 来做,作了几个部分的实验,RNAi,germline mosaic。
评价2:In IDM, students do not have an appointed teacher when they first arrived. Instead, they need to have rotation first. During rotation, new students will do
labwork under the direction of different teachers one after the other. It is t
he rotation that make new students be familiar with different teachers. And it is the rotation that provide oppotunities for teachers to know students better.
After students finish rotation, they will have one teacher as their "primary"
mentor. This appointment is based on a mutual selection mechanism. However, a
t the same time, all other teachers have nearly the same responsibility as the
"primary" mentor. In other words, students have shared mentors in IDM, while teachers have shared students as well. This unique feature makes IDM more like a super lab and make s it unnecessary to write to individual teacher for a better chance to be recruited.