概括
来自酵母的HOT1DNA序列通过利用RNA聚合酶I转录来刺激基因交换. 这个过程需要特定的DNA片段和转录通过同源序列进行增强的重组.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 酵母研究 酵母研究
背景情况:
- 在Saccharomyces cerevisiae中的核糖体RNA基因集群包含调节性DNA序列.
- 了解影响遗传交换的机制在分子生物学中至关重要.
研究的目的:
- 为了确定负责HOT1元素的重组刺激活性的DNA序列.
- 阐明HOT1增强酵母基因交换的机制.
主要方法:
- 在HOT1元素中分析DNA序列和定位功能域.
- 在Saccharomyces cerevisiae中进行基因分析,以测量重组率.
- 研究RNA聚合酶I转录在重组刺激中的作用.
主要成果:
- 在HOT1中,两个不连续的DNA片段对于重组刺激至关重要.
- 一个片段包含35S核糖体RNA的转录启动部位.
- 还需要RNA聚合酶I转录的增强剂;通过相邻的DNA转录是关键.
结论:
- 通过HOT1介导的重组刺激依赖于RNA聚合酶I的转录.
- 转录启动和通过同源序列的延长对于增强的基因交换是必要的.
- 插入一个转录终结位取消了HOT1的重组增强效应.
相关概念视频
DNA Base Pairing
Erwin Chargaff’s rules on DNA equivalence paved the way for the discovery of base pairing in DNA. Chargaff’s rules state that in a double-stranded DNA molecule,
Homologous Recombination
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
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...
Overview of Transposition and Recombination
Transposons make up a significant part of genomes of various organisms. Therefore, it is believed that transposition played a major evolutionary role in speciation by changing genome sizes and modifying gene expression patterns. For example, in bacteria, transposition can lead to conferring antibiotic resistance. Movement of transposable elements within the genetic pool of pathogenic bacteria can aid in transfer of antibiotic-resistant genetic elements. In eukaryotes, transposons can carry out...
Conservative Site-specific Recombination and Phase Variation
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
Homologous Recombination
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...


