Xist lncRNA利用了三维基因组架构,在X染色体中传播
Jesse M Engreitz1, Amy Pandya-Jones, Patrick McDonel
1Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA.
Science (New York, N.Y.)
|July 6, 2013
概括
在无活化过程中,Xist长非编码RNA (lncRNA) 通过利用其3D结构来覆盖X染色体. 结核菌通过修改染色体构造和进入活性区域而扩散到新的位置.
科学领域:
- 表观遗传学和基因组学
- 在RNA生物学,RNA生物学.
- 染色体规则 染色体规则
背景情况:
- 大型非编码RNAs (lncRNAs) 是染色质结构和功能的关键调节者.
- lncRNAs,如Xist,定位到它们的基因组点的精确机制在很大程度上是未知的.
- X染色体失活 (XCI) 是研究 lncRNA介导的表观遗传调节的一个关键模型系统.
研究的目的:
- 在X染色体失活 (XCI) 的启动和维持过程中,研究Xist lncRNA的局部化机制.
- 为了阐明Xist如何在X染色体上实现广泛的基因组向.
主要方法:
- 在XCI期间调查了Xist本地化动态.
- 分析了与X染色体构造和活跃转录区域的Xist相互作用.
主要成果:
- 在XCI启动过程中,Xist最初定位在远端的X染色体区域,独立于特定的DNA序列.
- Xist利用X染色体的三维 (3D) 构造来识别目标区域.
- 克西斯的沉默域对于其在积极转录的区域传播至关重要,使得全染色体覆盖成为可能.
结论:
- 克西斯通过3D搜索机制覆盖X染色体.
- Xist积极修改染色体结构,以促进其传播和访问新的基因组位置.
- 这项研究提出了 lncRNA 介导的全染色体表观遗传调节的新型模型.
相关概念视频
03:17Inheritance of Chromatin Structures
Epigenetics is the study of inherited changes in a cell's phenotype without changing the DNA sequences. It provides a form of memory for the differential gene expression pattern to maintain cell lineage, position-effect variegation, dosage compensation, and maintenance of chromatin structures such as telomeres and centromeres. For example, the structure and location of the centromere on chromosomes are epigenetically inherited. Its functionality is not dictated or ensured by the underlying DNA...
01:58X-Inactivation
The human X chromosome contains over ten times the number of genes as in the Y chromosome. Since males have only one X chromosome, and females have two, one might expect females to produce twice as many of the proteins, with undesirable results.
01:58X-inactivation
The human X chromosome contains over ten times the number of genes as in the Y chromosome. Since males have only one X chromosome, and females have two, one might expect females to produce twice as many of the proteins, with undesirable results.
02:39lncRNA - Long Non-coding RNAs
In humans, more than 80% of the genome gets transcribed. However, only around 2% of the genome codes for proteins. The remaining part produces non-coding RNAs which includes ribosomal RNAs, transfer RNAs, telomerase RNAs, and regulatory RNAs, among other types. A large number of regulatory non-coding RNAs have been classified into two groups depending upon their length – small non-coding RNAs, such as microRNA, which are less than 200 nucleotides in length, and long non-coding RNA (lncRNA)...
02:39lncRNA - Long Non-coding RNAs
In humans, more than 80% of the genome gets transcribed. However, only around 2% of the genome codes for proteins. The remaining part produces non-coding RNAs which includes ribosomal RNAs, transfer RNAs, telomerase RNAs, and regulatory RNAs, among other types. A large number of regulatory non-coding RNAs have been classified into two groups depending upon their length – small non-coding RNAs, such as microRNA, which are less than 200 nucleotides in length, and long non-coding RNA (lncRNA)...
02:32X and Y Chromosomes
Among mammals, the gender of an organism is determined by the sex chromosomes. Humans have two sex chromosomes, X and Y. Every human diploid cell has 22 pairs of autosomes and one pair of sex chromosomes. A human female has two X chromosomes, while a male has one X chromosome and one Y chromosome.
The germline cells such as egg and sperm cells carry only half the number of chromosomes, i.e., 22 autosomes and one sex chromosome. All eggs have an X chromosome, while sperm cells can carry an X or...
The germline cells such as egg and sperm cells carry only half the number of chromosomes, i.e., 22 autosomes and one sex chromosome. All eggs have an X chromosome, while sperm cells can carry an X or...