Separate sexes and the mitochondrial theory of ageing
Separate sexes and the mitochondrial theory of ageing
复制标题
DOI：
10.1006/jtbi.1996.0089
复制
发表时间：
1996-05-21
影响因子：
2
通讯作者：
Allen, JF
中科院分区：
文献类型：
--
作者：
Allen, JF
提出了一种假设，配子特化解决了线粒体功能和复制之间的冲突。线粒体的功能是通过氧化磷酸化合成 ATP，并与呼吸电子传递耦合。这需要线粒体遗传系统。然而，“不正确”的电子转移会产生导致突变的自由基，并且这些事件的频率会因突变而增加。因此，线粒体功能不利于线粒体复制的保真度。体细胞线粒体 DNA 的损伤可能会在个体生物体的寿命内累积，并确实决定其寿命。受精需要一个配子的运动性，并且需要 ATP。有人提出，雄配子通过牺牲线粒体DNA来进行电子转移及其诱变副产物，从而最大限度地提高运动能量，而雌配子则不能运动，抑制线粒体氧化磷酸化，从而保护线粒体DNA在代际间忠实传递。雄配子对受精卵的线粒体基因组没有贡献：线粒体是母系遗传的。这个可检验的假设可能有助于解释不同性别的进化及其一些特征。叶绿体的母系遗传可以用类似的方式解释，并且有助于植物中不同性别的维持。 (C) 1996 学术出版社有限公司
An hypothesis is presented by which gamete specialization resolves a conflict between the function and replication of mitochondria. The function of mitochondria is to synthesize ATP by oxidative phosphorylation, which is coupled to respiratory electron transport. This requires a mitochondrial genetic system. However, ''incorrect'' electron transfers produce free radicals that cause mutation, and the frequency of these events is increased by mutation. Mitochondrial function is therefore detrimental to the fidelity of mitochondrial replication. Damage to somatic mitochondrial DNA may accumulate within, and indeed determine, the life span of individual organisms. Motility of one gamete is required for fertilization, and requires ATP. It is proposed that male gametes maximize energy production for motility by sacrificing mitochondrial DNA to electron transfer and its mutagenic by-products, while female gametes, which are non-motile, repress mitochondrial oxidative phosphorylation, thus protecting mitochondrial DNA for faithful transmission between generations. Male gametes then make no contribution to the mitochondrial genome of the zygote: mitochondria are maternally inherited. This testable hypothesis may help to explain the evolution of separate sexes and a number of their characteristics. Maternal inheritance of chloroplasts may be explained in a similar way, and contribute to the maintenance of separate sexes in plants. (C) 1996 Academic Press Limited