Kawahara Manabu, Koyama Shiori, Iimura Satomi, Yamazaki Wataru, Tanaka Aiko, Kohri Nanami, Sasaki Keisuke, Takahashi Masashi
Laboratory of Animal Breeding and Reproduction, Research Faculty of Agriculture, Hokkaido University, Kita-ku Kita 9 Nishi 9, Sapporo 060-8589, Japan.
Sci Rep. 2015 Sep 29;5:14512. doi: 10.1038/srep14512.
Mitochondria, cellular organelles playing essential roles in eukaryotic cell metabolism, are thought to have evolved from bacteria. The organization of mtDNA is remarkably uniform across species, reflecting its vital and conserved role in oxidative phosphorylation (OXPHOS). Our objectives were to evaluate the compatibility of xenogeneic mitochondria in the development of preimplantation embryos in mammals. Mouse embryos harbouring bovine mitochondria (mtB-M embryos) were prepared by the cell-fusion technique employing the haemagglutinating virus of Japan (HVJ). The mtB-M embryos showed developmental delay at embryonic days (E) 3.5 after insemination. Furthermore, none of the mtB-M embryos could implant into the maternal uterus after embryo transfer, whereas control mouse embryos into which mitochondria from another mouse had been transferred developed as well as did non-manipulated embryos. When we performed quantitative PCR (qPCR) of mouse and bovine ND5, we found that the mtB-M embryos contained 8.3% of bovine mitochondria at the blastocyst stage. Thus, contamination with mitochondria from another species induces embryonic lethality prior to implantation into the maternal uterus. The heteroplasmic state of these xenogeneic mitochondria could have detrimental effects on preimplantation development, leading to preservation of species-specific mitochondrial integrity in mammals.
线粒体是在真核细胞代谢中发挥重要作用的细胞器，被认为是由细菌进化而来的。线粒体DNA（mtDNA）的组织在物种间非常一致，这反映了其在氧化磷酸化（OXPHOS）中至关重要且保守的作用。我们的目标是评估异种线粒体在哺乳动物植入前胚胎发育中的兼容性。通过使用日本血凝病毒（HVJ）的细胞融合技术制备了携带牛线粒体的小鼠胚胎（mtB-M胚胎）。mtB-M胚胎在受精后第3.5天（E3.5）显示出发育延迟。此外，在胚胎移植后，没有一个mtB-M胚胎能够植入母体子宫，而转入来自另一只小鼠线粒体的对照小鼠胚胎发育情况与未处理的胚胎一样。当我们对小鼠和牛的ND5进行定量PCR（qPCR）时，我们发现mtB-M胚胎在囊胚阶段含有8.3%的牛线粒体。因此，来自另一个物种的线粒体污染在植入母体子宫之前就会导致胚胎致死。这些异种线粒体的异质性状态可能对植入前发育产生有害影响，从而导致哺乳动物中物种特异性线粒体完整性得以保留。
