概括
谢诺普斯·莱维斯卵细胞含有两种类型的基因素信使RNA (mRNA). 一种类型含有多-A尾部,而另一种类型缺乏它,两种类型都编码了组织蛋白.
科学领域:
- 分子生物学分子生物学
- 发展生物学 发展生物学
- 基因表达 基因表达
背景情况:
- 在各种生物系统中,质子信使RNA (mRNA) 通常缺乏多元A尾.
- 之前的研究表明,基因组mRNA通常非多氨基酸.
研究的目的:
- 为了研究在Xenopus laevis卵细胞中基因素mRNA的存在和特征.
- 为了确定这个特定系统中是否含有多A的mRNA编码基因素.
主要方法:
- 使用无小麦生殖细胞系统进行由Xenopus laevis卵细胞mRNA指导的蛋白质合成.
- 采用聚烯胺凝电泳,氨基酸合并测试,化裂变和三性映射来表征合成的组分蛋白.
- 使用oligo(dT) 纤维素染色学来评估基因组编码mRNA的多基化状态.
主要成果:
- 在Xenopus laevis卵细胞中确定了含有多A的mRNA,该mRNA指导真实基因组的合成.
- 通过凝上的协同迁移确认了基因组合成,缺乏基的结合,在H2A中进行差异性氨基酸 (lysine和methionine) 的结合,H2A对酸裂变的抵抗,以及匹配的基图.
- 证明基因组编码RNA与oligo(dT) - 纤维素结合,表明多元 (A) 序列的附着,即使在变性化后.
- 还发现,使用相同的标准,多A缺乏RNA (7S-14S分数) 编码基因子.
结论:
- 谢诺普斯·莱维斯卵细胞具有两种不同的基因组mRNA类:一种是多基和一种非多基.
- 含有多甲基和缺少多甲基组素mRNA的存在表明,在卵细胞发育中具有潜在的调节作用.
相关概念视频
Transcription Factors
Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...
Chromatin Structure Regulates pre-mRNA Processing
In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into functional proteins. For a long time, transcription and pre-mRNA processing were considered two independent events that occur sequentially in the cell. However, it has now been well established that transcription and pre-mRNA processing are two simultaneous processes that are precisely regulated inside the cell.
The chromatin structure, especially...
The chromatin structure, especially...
Cell Specific Gene Expression
Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same parent cells. The differences in the cells can be attributed to the differential gene expression. Liver cells, whose functions include detoxification of blood, production of bile to metabolize fats, and synthesis of proteins essential for metabolism, must express a specific set of genes to perform their functions. Gene expression also varies with...
Regulation of Expression Occurs at Multiple Steps
Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence.
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Reporter Genes
Reporter genes are a type of protein-coding gene that are often tagged to a gene of interest. Once inside a target cell, reporter genes usually produce visually identifiable characteristics like fluorescence and luminescence when expressed along with the gene of interest. Thus, reporter genes “report” the presence or absence of genes of interest in an organism, determine the gene expression pattern, or track the physical location of a DNA segment or protein in the cell.
Commonly used reporter...
Commonly used reporter...
General Transcription Factors
Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...


