在精子生成过程中,从寡核酶体碎片中形成微同学介导的圆形DNA
Jun Hu1, Zhe Zhang2, Sai Xiao3
1State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Chemistry and Biomedicine Innovation Center (ChemBIC), Department of Andrology, Nanjing Drum Tower Hospital, Nanjing University, Nanjing, China.
eLife
|October 17, 2023
概括
外染色体圆形DNA (eccDNA) 在人类精子和小鼠精子生成过程中广泛形成. 这些圆形DNA分子起源于细胞死亡,并提供了一种评估精子质量的新方法.
科学领域:
- 遗传学 是一个遗传学.
- 分子生物学分子生物学
- 生殖生物学 生殖生物学
背景情况:
- 哺乳动物精子生成期间的异染色体循环DNA (eccDNA) 形成及其生物发生机制尚未得到充分理解.
- 在各种细胞类型中发现了eccDNA,但它们在生殖细胞中的特定作用和起源需要进一步研究.
研究的目的:
- 研究哺乳动物精子生成过程中eccDNA的景观和形成机制.
- 探索生殖线eccDNAs对人类精子质量评估的潜力.
- 阐明生殖细胞中eccDNA的主要生物发生途径.
主要方法:
- 对人类精子和小鼠精子生成过程中eccDNA形成的分析.
- 鉴定eccDNA大小和基因组起源 (euchromatin与 heterochromatin) 的特征.
- 开发一个生物信息管道,用于高分辨率的eccDNA检测,包括微同质的区域.
主要成果:
- 在人类精子和小鼠精子生成过程中观察到广泛的eccDNA形成.
- 生殖线eccDNAs来自垂死的细胞中的DNA碎片化,这表明它在精子质量评估中的作用.
- 小的eccDNA与 euchromatin 相结合,而大的eccDNA来自于异色色素.
- eccDNAs与de novo生殖线删除的相关性很小.
- 通过微同学介导的末端结合被确定为主要的eccDNA生物发生机制.
结论:
- 生殖线eccDNA的形成很普遍,与细胞死亡过程有关,为精子质量提供了一种新的标志物.
- 哺乳动物生殖细胞中的eccDNA生物发生主要由微同质介导的末端结合介导.
- 这项研究为男性生殖系中eccDNA的起源和形成提供了重要的见解.
相关概念视频
Homologous Recombination
50.6K
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
50.6K
Gene Conversion
9.8K
Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new...
9.8K
Meiosis I
193.7K
Meiosis is a carefully orchestrated set of cell divisions, the goal of which—in humans—is to produce haploid sperm or eggs, each containing half the number of chromosomes present in somatic cells elsewhere in the body. Meiosis I is the first such division, and involves several key steps, among them: condensation of replicated chromosomes in diploid cells; the pairing of homologous chromosomes and their exchange of information; and finally, the separation of homologous chromosomes by...
193.7K
Lampbrush Chromosomes
7.9K
In 1882, Flemming observed lampbrush chromosomes (LBC) in salamander eggs. Later in 1892, Rückert observed LBCs in shark egg cells and coined the term "lampbrush chromosomes" because they looked like brushes used to clean kerosene lamps.
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops...
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops...
7.9K
Spermatogenesis
102.6K
Spermatogenesis is the process by which haploid sperm cells are produced in the male testes. It starts with stem cells located close to the outer rim of seminiferous tubules. These spermatogonial stem cells divide asymmetrically to give rise to additional stem cells (meaning that these structures “self-renew”), as well as sperm progenitors, called spermatocytes. Importantly, this method of asymmetric mitotic division maintains a population of spermatogonial stem cells in the male...
102.6K
Replication in Eukaryotes
13.9K
In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus.
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...
13.9K


