科学家培育出只有一半基因组的胚胎干细胞
文章来源:未知 文章作者:enread 发布时间:2016-03-17 05:32 字体: [ ]  进入论坛
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Scientists from The Hebrew University of Jerusalem, Columbia University Medical Center (CUMC) and The New York Stem Cell Foundation Research Institute (NYSCF) have succeeded in generating a new type of embryonic2 stem cell that carries a single copy of the human genome, instead of the two copies typically found in normal stem cells. The scientists reported their findings today in the journal Nature. The stem cells described in this paper are the first human cells that are known to be capable of cell division with just one copy of the parent cell's genome.
 
Human cells are considered 'diploid' because they inherit two sets of chromosomes3, 46 in total, 23 from the mother and 23 from the father. The only exceptions are reproductive (egg and sperm4) cells, known as 'haploid' cells because they contain a single set of 23 chromosomes. These haploid cells cannot divide to make more eggs and sperm.
 
Previous efforts to generate embryonic stem cells using human egg cells had resulted in diploid stem cells. In this study, the scientists triggered unfertilized human egg cells into dividing. They then highlighted the DNA5 with a fluorescent6 dye and isolated7 the haploid stem cells, which were scattered8 among the more populous9 diploid cells.
 
The researchers showed that these haploid stem cells were pluripotent -- meaning they were able to differentiate10 into many other cell types, including nerve, heart, and pancreatic cells -- while retaining a single set of chromosomes. 
 
"This study has given us a new type of human stem cell that will have an important impact on human genetic11 and medical research," said Nissim Benvenisty, MD, PhD, Director of the Azrieli Center for Stem Cells and Genetic Research at the Hebrew University of Jerusalem and principal co-author of the study. "These cells will provide researchers with a novel tool for improving our understanding of human development, and the reasons why we reproduce sexually, instead of from a single parent."
 
The researchers were also able to show that by virtue12 of having just a single copy of a gene1 to target, haploid human cells may constitute a powerful tool for genetic screens. Being able to affect single-copy genes13 in haploid human stem cells has the potential to facilitate genetic analysis in biomedical fields such as cancer research, precision and regenerative medicine.
 
"One of the greatest advantages of using haploid human cells is that it is much easier to edit their genes," explained Ido Sagi, the PhD student who led the research at the Azrieli Center for Stem Cells and Genetic Research at the Hebrew University of Jerusalem. In diploid cells, detecting the biological effects of a single-copy mutation14 is difficult, because the other copy is normal and serves as "backup."


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1 gene WgKxx     
n.遗传因子,基因
参考例句:
  • A single gene may have many effects.单一基因可能具有很多种效应。
  • The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。
2 embryonic 58EyK     
adj.胚胎的
参考例句:
  • It is still in an embryonic stage.它还处于萌芽阶段。
  • The plan,as yet,only exists in embryonic form.这个计划迄今为止还只是在酝酿之中。
3 chromosomes 11783d79c0016b60332bbf1856b3f77d     
n.染色体( chromosome的名词复数 )
参考例句:
  • Chromosomes also determine the sex of animals. 染色体也决定动物的性别。 来自《简明英汉词典》
  • Each of four chromosomes divide longitudinally. 四种染色体的每一种都沿着纵向分裂。 来自《现代汉英综合大词典》
4 sperm jFOzO     
n.精子,精液
参考例句:
  • Only one sperm fertilises an egg.只有一个精子使卵子受精。
  • In human reproduction,one female egg is usually fertilized by one sperm.在人体生殖过程中,一个精子使一个卵子受精。
5 DNA 4u3z1l     
(缩)deoxyribonucleic acid 脱氧核糖核酸
参考例句:
  • DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
  • Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。
6 fluorescent Zz2y3     
adj.荧光的,发出荧光的
参考例句:
  • They observed the deflections of the particles by allowing them to fall on a fluorescent screen.他们让粒子落在荧光屏上以观察他们的偏移。
  • This fluorescent lighting certainly gives the food a peculiar color.这萤光灯当然增添了食物特别的色彩。
7 isolated bqmzTd     
adj.与世隔绝的
参考例句:
  • His bad behaviour was just an isolated incident. 他的不良行为只是个别事件。
  • Patients with the disease should be isolated. 这种病的患者应予以隔离。
8 scattered 7jgzKF     
adj.分散的,稀疏的;散步的;疏疏落落的
参考例句:
  • Gathering up his scattered papers,he pushed them into his case.他把散乱的文件收拾起来,塞进文件夹里。
9 populous 4ORxV     
adj.人口稠密的,人口众多的
参考例句:
  • London is the most populous area of Britain.伦敦是英国人口最稠密的地区。
  • China is the most populous developing country in the world.中国是世界上人口最多的发展中国家。
10 differentiate cm3yc     
vi.(between)区分;vt.区别;使不同
参考例句:
  • You can differentiate between the houses by the shape of their chimneys.你可以凭借烟囱形状的不同来区分这两幢房子。
  • He never learned to differentiate between good and evil.他从未学会分辨善恶。
11 genetic PgIxp     
adj.遗传的,遗传学的
参考例句:
  • It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
  • Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。
12 virtue BpqyH     
n.德行,美德;贞操;优点;功效,效力
参考例句:
  • He was considered to be a paragon of virtue.他被认为是品德尽善尽美的典范。
  • You need to decorate your mind with virtue.你应该用德行美化心灵。
13 genes 01914f8eac35d7e14afa065217edd8c0     
n.基因( gene的名词复数 )
参考例句:
  • You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因,所以能够活得很长。 来自《简明英汉词典》
  • Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪
14 mutation t1PyM     
n.变化,变异,转变
参考例句:
  • People who have this mutation need less sleep than others.有这种突变的人需要的睡眠比其他人少。
  • So far the discussion has centered entirely around mutation in the strict sense.到目前为止,严格来讲,讨论完全集中于围绕突变问题上。
TAG标签: genome stem cell
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