人类卵细胞中的线粒体DNA突变经历了频率依赖的选择,但不会随着年龄的增长而增加
Barbara Arbeithuber1,2, Kate Anthony2, Bonnie Higgins2
1Department of Gynaecology, Obstetrics and Gynaecological Endocrinology, Experimental Gynaecology and Obstetrics, Johannes Kepler University Linz, Altenberger Strasse 69, 4040 Linz, Austria.
bioRxiv : the preprint server for biology
|December 23, 2024
概括
线粒体DNA (mtDNA) 突变在血液和唾液中随着年龄的增长而增加,但在人类卵细胞中并非如此. 卵细胞mtDNA受到与年龄相关的突变的保护,防止疾病传播.
科学领域:
- 遗传学 是一个遗传学.
- 细胞生物学 细胞生物学
- 生殖生物学 生殖生物学
背景情况:
- 线粒体是提供细胞能量的关键器官.
- 线粒体DNA (mtDNA) 是从母亲遗传的,容易发生突变.
- 与年龄相关的mtDNA突变与疾病有关,但它们在人类卵细胞中的状态尚不清楚.
研究的目的:
- 为了研究人类卵细胞中随着年龄的增长而积累的新型mtDNA突变.
- 为了比较卵细胞中的突变模式与体质组织 (血液和唾液).
- 了解保护卵细胞mtDNA免受与年龄有关的突变的机制.
主要方法:
- 采用高度精确的双重测序来分析来自单个人类卵细胞,血液和唾液样本的全长mtDNA.
- 研究的女性年龄在20-42岁之间.
- 分析了编码和非编码mtDNA区域的突变频率和分布.
主要成果:
- 在所有分析的组织中检测到新的mtDNA突变.
- 在血液和唾液中观察到与年龄相关的mtDNA突变显著增加,但在卵细胞中没有.
- 发现了影响卵细胞mtDNA突变的频率依赖净化选择的证据.
- 在体质mtDNA的蛋白质编码区域中发现了有利于氨基酸变化的选择.
结论:
- 人类卵细胞mtDNA对随着衰老而积累的突变具有显著的保护.
- 与体组织相比,卵细胞中的线粒体DNA表现出明显的选择性压力.
- 这些发现对了解老龄化人口中与年龄相关的疾病和生殖健康有影响.
更多相关视频
11:08Combining Magnetic Sorting of Mother Cells and Fluctuation Tests to Analyze Genome Instability During Mitotic Cell Aging in Saccharomyces cerevisiae
Published on: October 16, 2014
12.5K
07:49Author Spotlight: Transmitochondrial Cybrid Generation Using Cancer Cell Lines
Published on: March 17, 2023
2.3K
相关概念视频
Animal Mitochondrial Genetics
7.5K
Among all the organelles in an animal cell, only mitochondria have their own independent genomes. Animal mitochondrial DNA is a double-stranded, closed-circular molecule with around 20,000 base pairs. Mitochondrial DNA is unique in that one of its two strands, the heavy, or H, -strand is guanine rich, whereas the complementary strand is cytosine rich and called the light, or L, -strand. Compared to nuclear DNA, mitochondrial DNA has a very low percentage of non-coding regions and is marked by...
7.5K
Oogenesis
63.4K
In human women, oogenesis produces one mature egg cell or ovum for every precursor cell that enters meiosis. This process differs in two unique ways from the equivalent procedure of spermatogenesis in males. First, meiotic divisions during oogenesis are asymmetric, meaning that a large oocyte (containing most of the cytoplasm) and minor polar body are produced as a result of meiosis I, and again following meiosis II. Since only oocytes will go on to form embryos if fertilized, this unequal...
63.4K
Nondisjunction
3.7K
Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate correctly and move to the opposite poles of the cells. This produces daughter cells with abnormal chromosome numbers. Nondisjunction is common during anaphase I or anaphase II of meiosis. Mutations in synaptonemal complex proteins that attach homologous chromosomes increase the chances of nondisjunction in anaphase I of meiosis I. In contrast, mutations in topoisomerases and condensins that hold...
3.7K
Meiosis I
38.1K
Meiosis is the division of a diploid cell into haploid cells forming sperm and eggs in animals through differentiation. Meiosis I is the first stage of meiosis, where the genetic recombination of homologous chromosomes and the reduction of the ploidy level by half occurs.
Prophase I is the most extended and complex step of meiosis I characterized by synapsis, chromosome pairing, and recombination of the homologous chromosomes. This process is facilitated by a proteinaceous structure called the...
Prophase I is the most extended and complex step of meiosis I characterized by synapsis, chromosome pairing, and recombination of the homologous chromosomes. This process is facilitated by a proteinaceous structure called the...
38.1K
Mitochondria
10.7K
Mitochondria are eukaryotic cellular organelles that are known to produce energy through a process called oxidative phosphorylation. Besides their primary function, mitochondria are involved in various cellular processes, including cell growth, differentiation, signaling, metabolism, and senescence. Age-related changes cause a decline in mitochondrial quality and integrity due to increased mitochondrial mutations and oxidative damage. Thus, aging can severely impact mitochondrial functions,...
10.7K
Meiosis vs. Mitosis
52.7K
Cell division is necessary for growth and reproduction in organisms. Mitosis aids cell growth and development by dividing somatic cells. In contrast, meiosis causes the division of germ cells and plays an essential role in sexual reproduction. Due to their unique functional requirements, mitosis and meiosis differ from each other in multiple aspects.
Before the start of mitosis and meiosis I, the cell synthesizes DNA, resulting in two homologous copies of each chromosome. DNA synthesis is...
Before the start of mitosis and meiosis I, the cell synthesizes DNA, resulting in two homologous copies of each chromosome. DNA synthesis is...
52.7K
