Yu Guanghui, Xiang Hai, Tian Jianhui, Yin Jingdong, Pinkert Carl A, Li Qiuyan, Zhao Xingbo
National Engineering Laboratory for Animal Breeding; Ministry of Agricultural Key Laboratory of Animal Genetics, Breeding and Reproduction; College of Animal Science and Technology, China Agricultural University, 100193, Beijing, China.
State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, 100193, Beijing, China.
Sci Rep. 2015 Aug 19;5:13118. doi: 10.1038/srep13118.
In farm animals, mitochondrial DNA mutations exist widely across breeds and individuals. In order to identify differences among mtDNA haplotypes, two porcine transmitochondrial cybrids were generated by fusion of a Lantang pig cell line devoid of mitochondrial DNA with enucleated cytoplasm from either a Large White pig or a Xiang pig harboring potentially divergent mitochondrial haplotypes. These cybrid cells were subjected to mitochondrial genome sequencing, copy number detecting and analysis of biochemical traits including succinate dehydrogenase (SDH) activity, ATP content and susceptibility to reactive oxygen species (ROS). The Lantang and Xiang mitochondrial genomes were highly homologous with only 18 polymorphic sites, and differed radically from the Large White with 201 and 198 mutations respectively. The Large White and Xiang cybrids exhibited similar mtDNA copy numbers and different values among biochemical traits, generated greater ROS production (P < 0.05) and less SDH activity (P < 0.05) and a lesser ATP content (P < 0.05). The results show that functional differences exist between cybrid cells which differ in mitochondrial genomic background. In conclusion, transmitochondrial cybrids provide the first direct evidence on pig biochemical traits linking different mitochondrial genome haplotypes.
在农场动物中，线粒体DNA突变广泛存在于各个品种和个体中。为了鉴定线粒体DNA单倍型之间的差异，通过将不含线粒体DNA的蓝塘猪细胞系与携带潜在不同线粒体单倍型的大白猪或香猪的去核细胞质融合，产生了两个猪转线粒体杂交细胞系。对这些杂交细胞系进行线粒体基因组测序、拷贝数检测以及包括琥珀酸脱氢酶（SDH）活性、ATP含量和对活性氧（ROS）敏感性在内的生化特性分析。蓝塘猪和香猪的线粒体基因组高度同源，仅有18个多态性位点，而与大白猪的线粒体基因组分别有201个和198个突变，差异极大。大白猪和香猪的杂交细胞系表现出相似的线粒体DNA拷贝数，但生化特性值不同，产生的ROS更多（P < 0.05），SDH活性更低（P < 0.05），ATP含量也更低（P < 0.05）。结果表明，线粒体基因组背景不同的杂交细胞系之间存在功能差异。总之，转线粒体杂交细胞系为猪不同线粒体基因组单倍型与生化特性之间的联系提供了首个直接证据。
