南极白血冰鱼中的血红蛋白基因集群删除由可移植元素促进
Thomas Desvignes1,2, Angel G Rivera-Colón3, John H Postlethwait2
1Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35233, USA.
Genome biology and evolution
|September 25, 2025
概括
南极冰鱼独特地缺乏血红蛋白,原因是血红蛋白基因集群的独立删除. 这项研究揭示了涉及tRNA基因放大和可转移元素的分子机制,导致了这种显著的进化损失.
科学领域:
- 进化生物学 进化生物学
- 基因组学就是基因组学.
- 分子进化分子进化
背景情况:
- 脊椎动物使用红细胞中的血红蛋白进行氧气运输.
- 南极冰鱼是一个例外,它拥有透明的血液,缺乏功能性血红蛋白.
- 冰鱼在进化过程中失去血红蛋白基因长期以来一直是一个科学.
研究的目的:
- 研究南极冰鱼祖先中两个主要的血红蛋白基因集群 (LA和MN) 丧失背后的分子机制.
- 了解冰鱼是如何弥补血红蛋白缺失的.
主要方法:
- 在十种红血型notothenioid物种和八种冰鱼物种中对血红蛋白集群区域进行比较基因组分析.
- 识别与基因群删除相关的分子机制,包括基因放大,可转移元素 (TE) 和基因周转.
主要成果:
- 洛杉矶血红蛋白集群很可能被删除,这是由于南极notothenioids的大规模tRNA基因放大和转换事件.
- MN血红蛋白删除是由物种特异性基因循环和其边界保留的可转移元素独立驱动的.
- 有证据表明,独立的分子机制导致了每个血红蛋白基因集群的丧失.
结论:
- 这项研究阐明了导致南极冰鱼失去血红蛋白基因集群的特定分子途径.
- 这些发现加深了我们对南极环境中冰鱼的进化适应和独特表型的理解.
相关概念视频
Exon Recombination
4.1K
The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon...
Exon shuffling follows “splice frame rules.” Each exon...
4.1K
Overview 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
DNA-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
Position-effect Variegation
7.0K
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
7.0K
Non-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
piRNA - Piwi-interacting RNAs
7.5K
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...
7.5K


