相关实验视频
Updated: Jan 16, 2026
11:52
Analysis of LINE-1 Retrotransposition at the Single Nucleus Level
Published on: April 23, 2016
8.8K
在Diphyllobothriidean条虫中的Saci2-Like LTR逆转移体的结构和进化分析
1Department of Microbiology and Lee Gil Ya Cancer and Diabetes Institute, Gachon University College of Medicine, Incheon 21999, Republic of Korea.
International journal of molecular sciences
|September 27, 2025
概括
双胞胎条虫保留了大型的,富含逆转移素的基因组,与紧的环状条虫基因组不同. 这项研究确定了在二烯基三烯基生物中功能性的Saci2逆转移体,与它们在循环四烯基生物中的降解形成鲜明对比.
科学领域:
- 基因组学就是基因组学.
- 进化生物学 进化生物学
- 寄生虫学的寄生虫学
背景情况:
- 环状线虫具有紧的基因组,与快速繁殖和可转移元素 (TE) 失活有关.
- 双胞胎带状虫具有大型的,富含逆转移体的基因组,但特定的逆转移体细节很少.
研究的目的:
- 为了研究 Saci2-like 长终端重复 (LTR) 逆转移体在 diphyllobothriidean cestodes 的多样性和进化动态.
- 为了比较diphyllobothriideans和cyclophyllideans之间的逆转移体样本,以了解基因组进化.
主要方法:
- 在Spirometra erinaceieuropaei和Sparganum proliferum中识别和注释Saci2类逆转移子.
- 对逆转移子序列的遗传学和分歧分析.
- 在diphyllobothriidean和cyclophyllidean物种之间进行比较基因组分析.
主要成果:
- 在多个二罗三类物种中发现了Saci2同类物种,分为至少八个家族,有显著的序列变异.
- 这些逆转移子在净化选择下保持结构和功能完整性,在S. proliferum中出现早期失活迹象.
- 双基因组三基因人保留功能性逆转移体,而环基因组三基因人显示逆转移体的降解,与基因组紧缩相关.
结论:
- 双胞胎三角形动物没有经历过强大的压力来进行基因组紧缩,允许保留功能性逆转移体.
- 基因组精简在循环类动物中,由生命历史特征 (如快速繁殖) 驱动,导致逆转移素的失活和退化.
- 基因组重塑和可转移元素的失活是相互影响的生物需求在metazoans.
相关概念视频
03:18Non-LTR Retrotransposons
13.2K
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...
13.2K
03:08LTR Retrotransposons
19.4K
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...
19.4K
02:13Overview of Transposition and Recombination
18.8K
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...
18.8K
01:15Diversity of Protists I
861
Excavata is a diverse group of protists that includes both chemoorganotrophic and phototrophic species, with some thriving in anaerobic environments. Among the key groups within Excavata are diplomonads and parabasalids, which are flagellated protists that lack mitochondria and chloroplasts. These microorganisms typically inhabit anoxic environments, such as the intestines of animals, where they exist either symbiotically or as parasites, relying on fermentation for energy production. Some...
861
02:33Retroviruses
14.6K
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’...
14.6K
02:57DNA-only Transposons
17.2K
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...
17.2K