相关实验视频
Updated: Jul 8, 2026
12:02
Molecular Evolution of the Tre Recombinase
Published on: May 29, 2008
这就是Erratum Erratum
Science (New York, N.Y.)
|April 27, 1984
概括
研究人员发现了一种与类风湿性关节炎相关的帕尔沃病毒 (RA-1). 这种病毒含有大约4.5千基的大小的单链DNA,为其在疾病中的作用提供了关键证据.
科学领域:
- 病毒学 病毒学
- 免疫学 免疫学 免疫学
- 类风湿病学 类风湿病学
背景情况:
- 类风湿性关节炎 (RA) 是一种慢性自身免疫性疾病.
- 已经研究了帕沃病毒在包括RA在内的人类疾病中的潜在作用.
- 以前的研究表明存在关联,但缺乏确的证据.
研究的目的:
- 为了提供确的证据,证明RA-1的身份是帕沃病毒.
- 为了调查类风湿性关节炎患者的帕尔沃病毒样颗粒的存在.
主要方法:
- 分析小鼠大脑中的24纳米颗粒,用患者的突细胞提取物接种后.
- 在含有传染性颗粒的CsCl梯度分数中检测单链DNA.
主要成果:
- 在正常小鼠或用非炎症性退行性关节疾病 (DJD) 患者的提取物接种的小鼠中没有检测到24nm颗粒.
- 成功地提取了单链DNA (大约. 从含有传染性24纳米粒子的CsCl梯度分数中获得4.5千基).
结论:
- 提取的DNA提供了确的证据,证明RA-1是一种帕维病毒.
- 这一发现加强了帕沃病毒与人类类风湿性关节炎之间的联系.
相关概念视频
01:43Proofreading
Synthesis of new DNA molecules starts when DNA polymerase links nucleotides together in a sequence that is complementary to the template DNA strand. DNA polymerase has a higher affinity for the correct base to ensure fidelity in DNA replication. The DNA polymerase furthermore proofreads during replication, using an exonuclease domain that cuts off incorrect nucleotides from the nascent DNA strand.Errors during Replication Are Corrected by the DNA Polymerase EnzymeGenomic DNA is synthesized in...
01:43Proofreading
Synthesis of new DNA molecules starts when DNA polymerase links nucleotides together in a sequence that is complementary to the template DNA strand. DNA polymerase has a higher affinity for the correct base to ensure fidelity in DNA replication. The DNA polymerase furthermore proofreads during replication, using an exonuclease domain that cuts off incorrect nucleotides from the nascent DNA strand.Errors during Replication Are Corrected by the DNA Polymerase EnzymeGenomic DNA is synthesized in...
01:44Termination of Translation
The large ribosomal subunit has several important structures essential to translation. These include the peptidyl transferase center (PTC) - which is the site where the peptide bond is formed - and a large, internal, water-filled tube through which the nascent polypeptide moves. This latter structure is called the Peptide Exit Tunnel, and it begins at the PTC and spans the body of the large ribosomal subunit. During translation, as the nascent polypeptide chain is synthesized, it passes through...
01:44Termination of Translation
The large ribosomal subunit has several important structures essential to translation. These include the peptidyl transferase center (PTC) - which is the site where the peptide bond is formed - and a large, internal, water-filled tube through which the nascent polypeptide moves. This latter structure is called the Peptide Exit Tunnel, and it begins at the PTC and spans the body of the large ribosomal subunit. During translation, as the nascent polypeptide chain is synthesized, it passes through...
01:31Proofreading
Synthesis of new DNA molecules is carried out by the enzyme DNA polymerase, which adds nucleotides on the daughter strand complementary to the template DNA strand. DNA polymerase has a higher affinity to add the correct base and ensures fidelity during DNA replication. Furthermore, it exhibits proofreading activity during replication, using an exonuclease domain that cuts off incorrect nucleotides from the nascent DNA strand.
Errors During Replication are Corrected by the DNA Polymerase Enzyme
Errors During Replication are Corrected by the DNA Polymerase Enzyme
01:15Variance
The deviations show how spread out the data are about the mean. A positive deviation occurs when the data value exceeds the mean, whereas a negative deviation occurs when the data value is less than the mean. If the deviations are added, the sum is always zero. So one cannot simply add the deviations to get the data spread. By squaring the deviations, the numbers are made positive; thus, their sum will also be positive.The standard deviation measures the spread in the same units as the data.