胚胎发育关键性蛋白质被确认
文章来源:未知 文章作者:meng 发布时间:2010-05-14 03:15 字体: [ ]  进入论坛
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Chromosome1 22q11 deletion syndrome2(综合症) (also known as DiGeorge syndrome) is the most common human chromosome(染色体) deletion syndrome, having an estimated incidence(影响,发生率) of at least one in 4,000 live births. It has a range of severity(严格,猛烈) but a multisystem impact, with symptoms that may include congenital(先天的,天生的) heart defects, immunologic and endocrine(内分泌的,激素的) abnormalities, cleft3(裂缝,龟裂) palate, gastrointestinal problems, and neuropsychiatric abnormalities. Nearly three-quarters of patients identified with this deletion syndrome have cardiac defects, and research into the underlying4 biology of this disorder5 has uncovered new knowledge of biological processes in both congenital heart disease(先天性心脏病) and early embryonic6 development.

In the May 2010 issue of Experimental Biology and Medicine, Jason Z. Stoller, M.D., of The Children's Hospital of Philadelphia, collaborating7 with Jonathan A. Epstein, M.D., scientific director of the Penn Cardiovascular Institute of the University of Pennsylvania, report on an important interaction of two proteins, Ash2l and Tbx1, during early mammalian(哺乳类) development. "In humans and other mammals, the heart is among the first organs to develop," said Stoller. "Greater knowledge of biological events that occur in the earliest stages of development helps us to better understand both normal and abnormal heart development."

In cell and animal studies, the researchers discovered that Ash2l, a core component8 of a protein complex responsible for epigenetic modifications11, is absolutely essential to early embryogenesis; without this protein, mouse embryos13 did not survive past the first few days of gestation14.

The region of chromosome 22 that is most commonly lost in DiGeorge syndrome contains more than 30 genes12, among them the gene9 for the transcription factor(转录因子) Tbx1. The Tbx family of nuclear transcription factor proteins shares a T-box, a conserved15 DNA16 binding17 domain18 that mediates19 regulation of downstream genes. In 2005, Epstein and Stoller identified a domain within the Tbx1 protein that, when not functioning properly, plays a key role in causing DiGeorge syndrome in a subset of patients.

The current study aimed to identify proteins that interact with Tbx1 in a functionally20 important way that could shed light on the pathogenesis(发病机理) of DiGeorge syndrome. Using a yeast21 and cell culture studies, the researchers pinpointed22 the Ash2l protein as interacting with Tbx1. They then generated Ash2l knockout mice to further investigate the role of the Ash2l protein. Mouse embryos that did not express Ash21 died early in gestation(怀孕,妊娠期) —demonstrating that the protein is necessary for early development.

"The crucial requirement of the Ash2l protein", said Stoller, "suggests that it likely acts to regulate many developmental genes in mammals. As part of a histone(组蛋白) methyltransferase(甲基转移酶) complex, it regulates gene transcription by epigenetic mechanisms23".

Future clinical implications for children and adults with DiGeorge syndrome are yet unclear. These patients have a normal Ash2l gene, but the loss of Tbx1 may alter the interaction between Ash2l and Tbx1 and play a role in their disease, possibly by regulating downstream genes. Stoller added, "The fact that patients with this genetic10 syndrome are missing a copy of the Tbx1 gene suggests that reduced amounts of the Tbx1 protein may have biological effects that cause different features of the disease. Further research is needed to discover these specific mechanisms."

Dr. Steven R. Goodman, Editor-in-Chief of Experimental Biology and Medicine, said "Stoller et al have demonstrated that protein Ash2l is essential in early embryogenesis. Ash2l interacts with the transcription factor Tbx1 which resides in a chromosomal24 region commonly deleted in DiGeorge syndrome. This interesting study suggests possible mechanisms leading to congenital heart disease in DiGeorge syndrome."



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1 chromosome 7rUzX     
n.染色体
参考例句:
  • Chromosome material with exhibits of such behaviour is called heterochromatin.表现这种现象的染色体物质叫做异染色质。
  • A segment of the chromosome may become lost,resulting in a deletion.染色体的一个片段可能会丢失,结果产生染色体的缺失。
2 syndrome uqBwu     
n.综合病症;并存特性
参考例句:
  • The Institute says that an unidentified virus is to blame for the syndrome. 该研究所表示,引起这种综合症的是一种尚未确认的病毒。
  • Results indicated that 11 fetuses had Down syndrome. 结果表明有11个胎儿患有唐氏综合征。
3 cleft awEzGG     
n.裂缝;adj.裂开的
参考例句:
  • I hid the message in a cleft in the rock.我把情报藏在石块的裂缝里。
  • He was cleft from his brother during the war.在战争期间,他与他的哥哥分离。
4 underlying 5fyz8c     
adj.在下面的,含蓄的,潜在的
参考例句:
  • The underlying theme of the novel is very serious.小说隐含的主题是十分严肃的。
  • This word has its underlying meaning.这个单词有它潜在的含义。
5 disorder Et1x4     
n.紊乱,混乱;骚动,骚乱;疾病,失调
参考例句:
  • When returning back,he discovered the room to be in disorder.回家后,他发现屋子里乱七八糟。
  • It contained a vast number of letters in great disorder.里面七零八落地装着许多信件。
6 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。
7 collaborating bd93aed5558c4b146fa553d822f7c432     
合作( collaborate的现在分词 ); 勾结叛国
参考例句:
  • Joe is collaborating on the work with a friend. 乔正与一位朋友合作做那件工作。
  • He was not only learning from but also collaborating with Joseph Thomson. 他不仅是在跟约瑟福?汤姆逊学习,而且也是在和他合作。
8 component epSzv     
n.组成部分,成分,元件;adj.组成的,合成的
参考例句:
  • Each component is carefully checked before assembly.每个零件在装配前都经过仔细检查。
  • Blade and handle are the component parts of a knife.刀身和刀柄是一把刀的组成部分。
9 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。
10 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。
11 modifications aab0760046b3cea52940f1668245e65d     
n.缓和( modification的名词复数 );限制;更改;改变
参考例句:
  • The engine was pulled apart for modifications and then reassembled. 发动机被拆开改型,然后再组装起来。 来自《简明英汉词典》
  • The original plan had undergone fairly extensive modifications. 原计划已经作了相当大的修改。 来自《简明英汉词典》
12 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
13 embryos 0e62a67414ef42288b74539e591aa30a     
n.晶胚;胚,胚胎( embryo的名词复数 )
参考例句:
  • Somatic cells of angiosperms enter a regenerative phase and behave like embryos. 被子植物体细胞进入一个生殖阶段,而且其行为象胚。 来自辞典例句
  • Evolution can explain why human embryos look like gilled fishes. 进化论能够解释为什么人类的胚胎看起来象除去了内脏的鱼一样。 来自辞典例句
14 gestation L6ey2     
n.怀孕;酝酿
参考例句:
  • The gestation period can be anything between 95 and 150 days.妊娠期从95天至150天不等。
  • This film was two years in gestation.这部电影酝酿了两年。
15 conserved d1dc02a3bfada72e10ece79fe3aa19af     
v.保护,保藏,保存( conserve的过去式和过去分词 )
参考例句:
  • He conserved his energy for the game. 他为比赛而养精蓄锐。 来自《简明英汉词典》
  • Under these conditions, the total mechanical energy remains constant, or is conserved. 在这种条件下,总机械能保持不变或机械能保存。 来自辞典例句
16 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。
17 binding 2yEzWb     
有约束力的,有效的,应遵守的
参考例句:
  • The contract was not signed and has no binding force. 合同没有签署因而没有约束力。
  • Both sides have agreed that the arbitration will be binding. 双方都赞同仲裁具有约束力。
18 domain ys8xC     
n.(活动等)领域,范围;领地,势力范围
参考例句:
  • This information should be in the public domain.这一消息应该为公众所知。
  • This question comes into the domain of philosophy.这一问题属于哲学范畴。
19 mediates 9cf5b4b4c1ee4c1361a2114028f23c30     
调停,调解,斡旋( mediate的第三人称单数 ); 居间促成; 影响…的发生; 使…可能发生
参考例句:
  • We therefore investigated whether hypercoagulability mediates a beneficial effect during denovo atherogenesis. 因此我们研究了高凝在原位动脉粥样硬化形成中是否介导了有益的作用。
  • Not happy when the mood that how mediates oneself? 不开心的时候怎样调解自己的情绪?
20 functionally 07b8a8a682798862ca0c3d3a567f4c3d     
adv.机能上地,官能地
参考例句:
  • Objective To explore occlusion reconstruction by computer aided design (CAD) with functionally-generated pathway (FGP). 目的探索借助功能性?记录(functionally-generated pathway,FGP)技术进行口腔固定修复体计算机辅助设计(Computer aided Design,CAD)生理性建?的方法。 来自互联网
  • In this respect, the proceeding was functionally similar to a comparative licensing adjudication. 在这一点上,手续在作用上即类似于比较许可证发放的裁断。 来自英汉非文学 - 行政法
21 yeast 7VIzu     
n.酵母;酵母片;泡沫;v.发酵;起泡沫
参考例句:
  • Yeast can be used in making beer and bread.酵母可用于酿啤酒和发面包。
  • The yeast began to work.酵母开始发酵。
22 pinpointed e23273e2459d3a2f113ef7cdb8d1c728     
准确地找出或描述( pinpoint的过去式和过去分词 ); 为…准确定位
参考例句:
  • His refusal to help simply pinpointed his cowardice. 他拒绝帮助正显示他的胆小。
  • Computers pinpointed where the shells were coming from. 计算机确定了炮弹发射的位置。
23 mechanisms d0db71d70348ef1c49f05f59097917b8     
n.机械( mechanism的名词复数 );机械装置;[生物学] 机制;机械作用
参考例句:
  • The research will provide direct insight into molecular mechanisms. 这项研究将使人能够直接地了解分子的机理。 来自《简明英汉词典》
  • He explained how the two mechanisms worked. 他解释这两台机械装置是如何工作的。 来自《简明英汉词典》
24 chromosomal 13a3145acf874e52d34a5554025f79c6     
adj.染色体的
参考例句:
  • Like mRNA, both tRNA and rRNA are transcripts of chromosomal DNA. tRNA及rRNA同mRNA一样,都是染色体DNA的转录产物。 来自辞典例句
  • In mammalian species, a variety of chromosomal rearrangements are known to exist. 在哺乳类的物种中,已知有许多类型的染色体内部重新排列。 来自辞典例句
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