转移酶在大型真核生物基因组中的功能性作用
Mariusz Nowacki1, Brian P Higgins, Genevieve M Maquilan
1Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA.
概括
在Oxytricha trifallax中,转体酶基因主导大规模的DNA切除,在发育过程中消除转体子. 这揭示了转体酶在管理真核体基因组和以前被忽视的DNA中的关键作用.
科学领域:
- 基因组学就是基因组学.
- 分子生物学分子生物学
- 欧核生物基因调节 欧核生物基因调节
背景情况:
- 可转移元素 (TE) 构成了真核基因组的很大一部分,但通常被认为是无益的.
- 状动物Oxytricha trifallax在发育过程中经历了极端的基因组重组,消除了其95%的生殖基因组DNA,包括所有TE.
研究的目的:
- 为了研究生殖线受限转体酶基因在Oxytricha trifallax.在全基因组DNA切除过程中的作用.
- 了解转移酶在管理具有众多活跃TEs的大型真核体基因组中的功能.
主要方法:
- 在生殖系-体内基因分化过程中对转化酶基因表达的分析.
- 利用RNA干扰 (RNAi) 沉默转体酶活动.
- 观察转移酶沉默对后代DNA重组的影响.
主要成果:
- 鉴定出生殖系有限的转移酶基因是全基因组DNA切除的关键调解者.
- 转移酶基因表达在生殖线-体内基因分化过程中被暂时调节.
- 通过RNAi沉默转化酶导致后代的异常DNA重组.
结论:
- 转体酶在Oxytricha trifallax发育过程中对转体子DNA的编程消除中发挥着至关重要的作用.
- 这项研究重新定义了转基因酶的功能,突出了它们在大型真核生物基因组内基因组维护和重组中的重要性.
- 以前被忽视的基因组DNA ("垃圾DNA") 已被证明具有关键的,由转基因酶主导的活跃作用.
更多相关视频
04:04Real-Time Quantification of the Effects of IS200/IS605 Family-Associated TnpB on Transposon Activity
Published on: January 20, 2023
11:12Determination of the Optimal Chromosomal Location(s) for a DNA Element in Escherichia coli Using a Novel Transposon-mediated Approach
Published on: September 11, 2017
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...
Transposons
Transposons, or "jumping genes," are small mobile genetic elements (MGEs) that range from 700 to 40,000 base pairs in length. They are found in all organisms and can move within the same chromosome or transfer to different chromosomes. In some cases, transposons can also jump between different host DNA molecules, such as plasmids or viruses, contributing to genetic variability.Barbara McClintock first discovered these mobile genetic elements in the 1940s while studying maize genetics, and she...
Overview of Transposition and Recombination
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...
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...
piRNA - Piwi-interacting RNAs
PIWI-interacting RNAs, or piRNAs, are the most abundant short non-coding RNAs. More than 20,000 genes have been found in humans that code for piRNAs while only 2000 genes have been found for miRNAs. piRNAs can act at the transcriptional and post-transcriptional levels and have a vital role in silencing transposable elements present in germ cells. They are also involved in epigenetic silencing and activation. Previously, they were thought to function only in germ cells but new evidence suggests...
