Mitochondria as environments for the nuclear genome in Drosophila: Mitonuclear GxGxE

Mitochondria evolved from a union of microbial cells belonging to distinct lineages that were likely anaerobic. The evolution of eukaryotes required a massive reorganization of the two genomes and eventual adaptation to aerobic environments. The nutrients and oxygen that sustain eukaryotic metabolism today are processed in mitochondria through coordinated expression of 37 mitochondrial genes and over 1000 nuclear genes. This puts mitochondria at the nexus of gene-by-gene (GxG) and gene-by-environment (GxE) interactions that sustain life. Here we use a Drosophila model of mitonuclear genetic interactions to explore the notion that mitochondria are environments for the nuclear genome, and vice versa. We construct factorial combinations of mtDNA and nuclear chromosomes to test for epistatic interactions (GxG), and expose these mitonuclear genotypes to altered dietary environments to examine GxE interactions. We use development time and genome wide RNAseq analyses to assess the relative con...

线粒体起源于分属不同演化支系且大概率为厌氧型的微生物细胞的融合事件。真核生物的演化过程需要对两套基因组进行大规模重构，并最终适应有氧环境。现今支撑真核生物代谢的营养物质与氧气，需借助线粒体与细胞核的37个线粒体基因及千余个核基因的协同表达，在线粒体内完成代谢加工。这使得线粒体成为维系生命的基因间互作（gene-by-gene, GxG）与基因-环境互作（gene-by-environment, GxE）的核心枢纽。本研究借助线粒体-核互作的果蝇模型，探究“线粒体可作为核基因组的生存环境，反之亦然”这一假说。我们构建线粒体DNA（mtDNA）与核染色体的析因组合，以验证上位性互作（GxG）；同时将这些线粒体-核基因型暴露于改变的膳食环境中，以此探究GxE互作。我们通过发育时长与全基因组RNA测序（RNAseq）分析，评估相对的……