通过未配对的DNA来缓解微生物沉默
P K Shiu1, N B Raju, D Zickler
1Department of Biological Sciences, 385 Serra Mall, Stanford University, Stanford, CA 94305, USA. ktshiu@stanford.edu
Cell
|January 10, 2002
概括
不配对DNA (MSUD) 的 meiotic silencing是一个新描述的过程,在这种过程中,不配对DNA在半变异过程中沉默同源DNA. 一种Neurospora突变体,Sad-1,未能执行MSUD,从而提供了对介质基因功能的见解.
科学领域:
- 遗传学 是一个遗传学.
- 分子生物学分子生物学
- 菌类学 菌类学是指菌类学.
背景情况:
- 基因沉默机制,如共抑制 (植物) 和抑制 (真菌),当DNA段过多时就会发生.
- 弥生是性繁殖的关键细胞分裂过程.
研究的目的:
- 描述一个新型的基因沉默过程在半变化过程中,称为未配对DNA (MSUD) 的半变性沉默.
- 为了研究MSUD的遗传基础,使用Neurospora突变物Sad-1.
- 探索MSUD对理解介质基因功能和生殖隔离的影响.
主要方法:
- 通过未配对DNA (MSUD) 现象表征介质沉默.
- 对影响MSUD的半主导性神经突变Sad-1的基因分析.
- 对Sad-1的表型分析与其他介质突变相比.
主要成果:
- MSUD在半分裂过程中沉默所有与未配对DNA同源的DNA,包括配对的基因.
- 萨德-1突变体在MSUD中有缺陷,并且抑制了阿斯库斯主导突变体的性表型.
- 野生类型的等位基因,sad-1(+),编码了一个假定的RNA指向RNA聚合酶.
结论:
- MSUD是一种独特的基因沉默机制,在变化过程中运行.
- Sad-1基因对MSUD至关重要,并且可能在调节介质过程中发挥作用.
- MSUD可以提供对基本介质基因的洞察力,并有助于Neurospora的生殖隔离.
相关概念视频
Genomic DNA in Eukaryotes
Eukaryotes have large genomes compared to prokaryotes. To fit their genomes into a cell, eukaryotic DNA is packaged extraordinarily tightly inside the nucleus. To achieve this, DNA is tightly wound around proteins called histones, which are packaged into nucleosomes that are joined by linker DNA and coil into chromatin fibers. Additional fibrous proteins further compact the chromatin, which is recognizable as chromosomes during certain phases of cell division.
DNA as a Genetic Template
Two structural features of the DNA molecule provide a basis for the mechanisms of heredity: the four nucleotide bases and its double-stranded nature. The Watson-Crick model of double-helical DNA structure, proposed in 1952, drew heavily upon the X-ray crystallography work of researchers Rosalind Franklin and Maurice Wilkins. Watson, Crick, and Wilkins jointly received the Nobel Prize in Physiology or Medicine for their work in 1962. Franklin was, controversially, excluded from the prize for...
Gene Conversion
Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new...
DNA Microarrays
Microarrays are high-throughput and relatively inexpensive assays that can be automated to analyze large quantities of data at a time. They are used in genome-wide studies to compare gene or protein expression under two varied conditions, such as healthy and diseased states. Microarrays consist of glass or silica slides on which probe molecules are covalently attached through surface functionalization. Most commonly, the slides are prepared through the chemisorption of silanes to silica...
Restriction Enzymes
Restriction enzymes are bacterial enzymes used to cut DNA in a sequence-specific manner. To cleave DNA, they bind to specific palindromic sequences called restriction sites. Such palindromic DNA sequences or inverted repeats are commonly found in regions of functional significance, such as the origin of replication, gene operator sites, and regions containing transcription termination signals.
The host bacteria protect their own genomic DNA from these enzymes by methylating these sites. Some...
The host bacteria protect their own genomic DNA from these enzymes by methylating these sites. Some...
DNA as a Genetic Template
Two structural features of the DNA molecule provide a basis for the mechanisms of heredity: the four nucleotide bases and its double-stranded nature. The Watson-Crick model of double-helical DNA structure, proposed in 1952, drew heavily upon the X-ray crystallography work of researchers Rosalind Franklin and Maurice Wilkins. Watson, Crick, and Wilkins jointly received the Nobel Prize in Physiology or Medicine for their work in 1962. Franklin was, controversially, excluded from the prize for...


