相关实验视频
Updated: Apr 28, 2026

07:47
Microscopy of Fission Yeast Sexual Lifecycle
Published on: March 9, 2016
14.4K
概括
研究人员在Saccharomyces cerevisiae交配类型位点 (MAT,HMR,HML) 中确定了共同的DNA序列. 特定的alpha或a-phenotype序列被同类区域围绕着,这表明DNA转移用于匹配类型切换.
科学领域:
- 分子生物学分子生物学
- 酵母遗传学 酵母遗传学
背景情况:
- 在Saccharomyces cerevisiae中的交配类型位置 (MAT) 决定了酵母的交配行为.
- 已知静音交配类型的位点 (HMR和HML) 影响活跃的MAT位点.
研究的目的:
- 阐明Saccharomyces cerevisiae中的交配类型位点的结构组织和序列同质性.
- 为了研究参与交配类型相互转换的DNA序列.
主要方法:
- 隔离一个含有MATα交配类型位点的重组等离子体.
- 使用MAT,HMR和HML位置的限制片段进行杂交研究.
- 再组合兰巴达克隆分离和异质复杂分析以比较位置结构.
主要成果:
- 所有交配类型位点 (MAT,HMR,HML) 都具有共同的DNA序列.
- 阿尔法表型位点 (MATα,HMLα) 含有850 bp的α特异序列;a表型位点 (MATa,HMRa) 含有700 bp的a特异序列.
- 存在不同长度的同质侧边区域,其中HMLα和HMRa与MAT位置呈现差异性同质性.
结论:
- 配对类型位点的结构组织支持用于配对类型切换的DNA转移模型.
- 特定的DNA序列是HML位点的特征,无论它们的a或alpha特异性含量如何.
- 这些发现提供了对基因机制的见解,这些基因机制是结合类型的决定和酵母的切换的基础.
相关概念视频
Yeast Signaling
15.6K
Yeasts are single-celled organisms, but unlike bacteria, they are eukaryotes (cells with a nucleus). Cell signaling in yeast is similar to signaling in other eukaryotic cells. A ligand, such as a protein or a small molecule released from a yeast cell, attaches to a receptor on the cell surface. The binding stimulates second-messenger kinases to activate or inactivate transcription factors that further regulate gene expression. Many of the yeast intracellular signaling cascades have similar...
15.6K
Overview of Transposition and Recombination
16.3K
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...
16.3K
DNA-only Transposons
15.8K
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...
15.8K
LTR Retrotransposons
18.0K
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...
18.0K
Non-LTR Retrotransposons
12.4K
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...
12.4K
Transposons
3.2K
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...
3.2K

