Centre for Genetic Diseases, Hudson Institute of Medical Research, Clayton, VIC 3168, Australia.
Department of Molecular and Translational Sciences, Monash University, Clayton, VIC 3168, Australia.
Sci Rep. 2018 May 8;8(1):7246. doi: 10.1038/s41598-018-25516-3.
We generated cattle embryos using mitochondrial supplementation and somatic cell nuclear transfer (SCNT), named miNT, to determine how additional mitochondrial DNA (mtDNA) modulates the nuclear genome. To eliminate any confounding effects from somatic cell mtDNA in intraspecies SCNT, donor cell mtDNA was depleted prior to embryo production. Additional oocyte mtDNA did not affect embryo development rates but increased mtDNA copy number in blastocyst stage embryos. Moreover, miNT-derived blastocysts had different gene expression profiles when compared with SCNT-derived blastocysts. Additional mtDNA increased expression levels of genes involved in oxidative phosphorylation, cell cycle and DNA repair. Supplementing the embryo culture media with a histone deacetylase inhibitor, Trichostatin A (TSA), had no beneficial effects on the development of miNT-derived embryos, unlike SCNT-derived embryos. When compared with SCNT-derived blastocysts cultured in the presence of TSA, additional mtDNA alone had beneficial effects as the activity of glycolysis may increase and embryonic cell death may decrease. However, these beneficial effects were not found with additional mtDNA and TSA together, suggesting that additional mtDNA alone enhances reprogramming. In conclusion, additional mtDNA increased mtDNA copy number and expression levels of genes involved in energy production and embryo development in blastocyst stage embryos emphasising the importance of nuclear-mitochondrial interactions.
我们使用线粒体补充和体细胞核移植（SCNT）生成牛胚胎，命名为 miNT，以确定额外的线粒体 DNA（mtDNA）如何调节核基因组。为了消除种内 SCNT 中体细胞 mtDNA 的任何混杂影响，在胚胎产生之前耗尽供体细胞 mtDNA。额外的卵母细胞 mtDNA 不会影响胚胎发育率，但会增加囊胚阶段胚胎的 mtDNA 拷贝数。此外，与 SCNT 衍生的囊胚相比，miNT 衍生的囊胚具有不同的基因表达谱。额外的 mtDNA 增加了参与氧化磷酸化、细胞周期和 DNA 修复的基因的表达水平。与 SCNT 衍生的胚胎不同，在胚胎培养培养基中添加组蛋白去乙酰化酶抑制剂 Trichostatin A（TSA）对 miNT 衍生胚胎的发育没有有益影响。与在 TSA 存在下培养的 SCNT 衍生囊胚相比，单独添加额外的 mtDNA 具有有益的效果，因为糖酵解的活性可能增加，胚胎细胞死亡可能减少。然而，当额外的 mtDNA 和 TSA 一起添加时，并没有发现这些有益的效果，这表明额外的 mtDNA 单独增强了重编程。总之，额外的 mtDNA 增加了囊胚阶段胚胎中线粒体 DNA 拷贝数和参与能量产生和胚胎发育的基因的表达水平，强调了核-线粒体相互作用的重要性。
