相关实验视频
Updated: Jul 23, 2026

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Xenopus laevis as a Model to Identify Translation Impairment
Published on: September 27, 2015
概括
研究人员确定了18S核糖体RNA (rRNA) 序列靠近5'末端,28SrRNA序列靠近Xenopus laevis的rRNA前体分子3'末端. 这种极性是使用电子显微镜和限制酶消化来确定的.
科学领域:
- 分子生物学分子生物学
- 遗传学 遗传学 是一个
- 发展生物学 发展生物学
背景情况:
- 核糖体RNA (rRNA) 前体分子对于核糖体生物发生是必不可少的.
- 确定前体内的rRNA序列的精确排列对于理解转录和处理至关重要.
- 之前对Xenopus laevis的研究并没有确定rRNA前体的极性.
研究的目的:
- 在Xenopus laevis的rRNA前体分子内明确分配18S和28S核糖体RNA序列的5'和3'极性.
- 在这个模型生物体中提供详细的了解rRNA基因转录和处理.
主要方法:
- 在Xenopus laevis中的核糖体基因转录复合体的放大.
- 用EcoRI限制性内核酶对放大转录复合物的消化.
- 分裂转录复合物的扩散用于电子显微镜分析.
- 对新生rRNA链长度和EcoRI切割点位置的分析.
主要成果:
- 18S rRNA序列在rRNA前体分子的5'端附近进行了映射.
- 28S rRNA序列在rRNA前体分子的3'端附近进行了映射.
- 来自限制消化和电子显微镜的综合数据为rRNA前体极性提供了明确的证据.
结论:
- 在Xenopus laevis中,rRNA前体分子的极性已被确定为确定的.
- 这一发现澄清了前体内的rRNA序列的空间组织,有助于未来对rRNA处理的研究.
- 采用的方法为其他rRNA系统中类似的极性赋值提供了强大的方法.
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...
pre-mRNA Processing
In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl guanosine). This 5’ cap helps the...
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl guanosine). This 5’ cap helps the...
Ribosomal RNA Synthesis
Ribosome synthesis is a highly complex and coordinated process involving more than 200 assembly factors. The synthesis and processing of ribosomal components occurs not only in the nucleolus but also in the nucleoplasm and the cytoplasm of eukaryotic cells.
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
mRNA Stability and Gene Expression
The structure and stability of mRNA molecules regulates gene expression, as mRNAs are a key step in the pathway from gene to protein. In eukaryotes, the half-life of mRNA varies from a few minutes up to several days. mRNA stability is essential in growth and development. The absence of the proteins regulating its stability, such as tristetraprolin in mice, can cause systemic issues, including bone marrow overgrowth, inflammation, and autoimmunity.
Cis-acting Elements involved in mRNA stability
Cis-acting Elements involved in mRNA stability
Pre-mRNA Processing: Modification of pre-mRNA Ends
In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps the cell...
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps the cell...
Ribosomal RNA Synthesis
Ribosome synthesis is a highly complex and coordinated process involving more than 200 assembly factors. The synthesis and processing of ribosomal components occurs not only in the nucleolus but also in the nucleoplasm and the cytoplasm of eukaryotic cells.
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...

