概括
莫洛尼小鼠白血病病毒 (Mo-MuLV) 基因组分析显示了终端冗余. 寡核酸映射和RNA-DNA杂交证实了49-60核酸在基因组两端的重复.
科学领域:
- 病毒学 病毒学
- 分子生物学分子生物学
- 基因组学就是基因组学.
背景情况:
- 鼠类白血病病毒的Moloney菌株 (Mo-MuLV) 是一种具有单链RNA基因组的逆转录病毒.
- 了解病毒基因组的精确结构对于理解其复制和病原机制至关重要.
研究的目的:
- 阐明Mo-MuLV的基因组结构,特别是调查潜在的终端冗余.
- 绘制病毒RNA寡核酸的地图,并确定它们在Mo-MuLV基因组中的位置.
主要方法:
- 使用核糖核酶T1.1.消化Mo-MuLVRNA的过程.
- 使用二维凝电泳分离消化产品.
- 基于3'终端RNA片段的产量进行的寡核酸映射.
- 混合化Mo-MuLVRNA到强阻断DNA (5'终端序列),然后进行RNase消化.
主要成果:
- 从Mo-MuLV RNA中分离和鉴定了30种大型寡核酸.
- 核酸21在两倍的摩尔产量中被发现,这表明它存在于多个基因组位置.
- 测绘表明,在基因组的5'和3'末端附近,有Oligonucleotide 21.
- 对混合为强阻断DNA的RNA的分析证实了某些寡核酸的存在,包括21个,在两个末端.
结论:
- 莫-穆尔维基因组具有49-60个核酸的终端冗余.
- 这一发现为Mo-MuLV.的结构组织和潜在的复制策略提供了关键的见解.
相关概念视频
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...
Retroviruses
Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
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...
Leaky Scanning
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for...
Size and Structure of Viral Genomes
Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. These genomes consist of either DNA or RNA and may be linear or circular. Additionally, they can be single-stranded or double-stranded, with each configuration affecting how the virus propagates within a host. RNA viruses, for instance, generally have smaller genomes than DNA viruses, a factor that contributes to their high mutation rates and...


