Recently, we generated mtDNA-based disease mice (mito mice) by introduction of respiration-deficient mitochondria possessing pathogenic mutant mtDNA with a 4696 bp deletion (deltamtDNA4696) from somatic cells into mouse zygotes. Mito mice and cytochrome c oxidase (COX) electronmicrographs, that could identify the respiration enzyme activity at individual mitochondrial levels, enabled precise investigation of the pathogenesis of deltamtDNA4696. All the observations represented unambiguous evidence for the presence of extensive and continuous exchange of genetic contents between mitochondria. Thus, the inter-mitochondrial interaction could correspond to a very unique and effective defense system of the highly oxidative organelles for preventing mice and human subjects from expressing mitochondrial dysfunction caused by mtDNA lesions, which have been continuously created by oxidative stresses during aging. Here, we would like to propose a new hypothesis on mitochondrial biogenesis, 'the interaction theory of mammalian mitochondria': mitochondria exchange genetic contents, and thus lose individuality and function as a single dynamic cellular unit.

中文翻译：

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小鼠和人类受试者线粒体的新型防御系统，用于防止致病突变 mtDNA 表达线粒体功能障碍

最近，我们通过将具有 4696 bp 缺失 (deltamtDNA4696) 的致病突变 mtDNA 从体细胞引入小鼠受精卵的呼吸缺陷线粒体，产生了基于 mtDNA 的疾病小鼠（mito 小鼠）。Mito 小鼠和细胞色素 c 氧化酶 (COX) 电子显微照片可以识别个体线粒体水平的呼吸酶活性，从而能够精确研究 deltamtDNA4696 的发病机制。所有观察结果都清楚地证明了线粒体之间存在广泛和持续的遗传内容交换。因此，线粒体间相互作用可能对应于高度氧化细胞器的一个非常独特和有效的防御系统，用于防止小鼠和人类受试者表达由 mtDNA 损伤引起的线粒体功能障碍，老化过程中氧化应激不断产生。在这里，我们想提出一个关于线粒体生物发生的新假说，即“哺乳动物线粒体相互作用理论”：线粒体交换遗传内容，从而失去作为单个动态细胞单元的个性和功能。