转换一个II组内的转换
C H Sellem1, G Lecellier, L Belcour
1Centre de Génétique Moléculaire CNRS, Gif-sur-Yvette, France.
Nature
|November 11, 1993
概括
自己拼接的内子,移动的遗传元素,可以通过转移移动. 这项研究为Podospora anserina的II组内置转移提供了证据,这可能解释线粒体DNA缺失和真菌衰老.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 菌群学 菌群学 菌群学是指菌群学
背景情况:
- 自剪接的内子是根据结构分类为I组或II组的移动遗传元素.
- 内体的移动性主要是通过指引,一种特定的基因入侵过程来证明的.
- 内部转移,虽然预测,缺乏进化传播的直接实验证据.
研究的目的:
- 提供实验证据,证明内部转移作为内部移动的机制.
- 为了研究II组内突转移在真菌线粒体基因组动态中的作用.
- 为了探索内部转移,线粒体DNA删除和Podospora anserina的衰老之间的潜在联系.
主要方法:
- 用聚合酶连锁反应 (PCR) 实验来检测内子运动.
- 遗传学分析和体外逆拼接实验为研究的预测提供了信息.
- 在Podospora anserina进行了线粒体染色体缺失的分析.
主要成果:
- PCR结果提供了与II组内突转移一致的证据.
- 在Podospora anserina的线粒体染色体中发现了特定位点的缺失.
- 这种删除与真菌的过早死亡综合征有关.
结论:
- 第二组内转移是内移动的一个可行的机制,支持进化的内传播.
- 内部转换与Podospora anserina观察到的线粒体DNA缺失有关.
- 这种转移事件可能在Podospora anserina的衰老过程中发挥作用.
相关概念视频
RNA Splicing
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
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...
DNA-only Transposons
DNA-only transposons are called autonomous transposons since they code for the enzyme transposase that is required for the transposition mechanism. Insertion of transposons can alter gene functions in multiple ways. They can mutate the gene, alter gene expression by introducing a novel promoter or insulator sequence, introduce new splice sites, and change the mRNA transcripts produced, or remodel chromatin structure.
The donor site from where the transposon is excised is either degraded or...
The donor site from where the transposon is excised is either degraded or...
LTR Retrotransposons
LTR retrotransposons are class I transposable elements with long terminal repeats flanking an internal coding region. These elements are less abundant in mammals compared to other class I transposable elements. About 8 percent of human genomic DNA comprises LTR retrotransposons. Some of the common examples of LTR retrotransposons are Ty elements in yeast and Copia elements in Drosophila.
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...
Non-LTR Retrotransposons
As the name suggests, non-LTR retrotransposons lack the long terminal repeats characteristic of the LTR retrotransposons. Additionally, both LTR and non-LTR retrotransposons use distinct mechanisms of mobilization. Non-LTR retrotransposons are further divided into two classes - Long interspersed nuclear elements (LINEs) and short interspersed nuclear elements (SINEs), both of which occur abundantly in most mammals, including humans. Some of the active non-LTR retrotransposons in humans are L1...
Transposons
Transposons, or "jumping genes," are small mobile genetic elements (MGEs) that range from 700 to 40,000 base pairs in length. They are found in all organisms and can move within the same chromosome or transfer to different chromosomes. In some cases, transposons can also jump between different host DNA molecules, such as plasmids or viruses, contributing to genetic variability.Barbara McClintock first discovered these mobile genetic elements in the 1940s while studying maize genetics, and she...


