title: Quantitative analysis of mitochondrial DNAs in macaque embryos reprogrammed by rabbit oocytes.
abstract: In cloned animals where somatic cell nuclei and oocytes are from the same or closely related species, the mitochondrial DNA (mtDNA) of the oocyte is dominantly inherited. However, in nuclear transfer (NT) embryos where nuclear donor and oocyte are from two distantly related species, the distribution of the mtDNA species is not known. Here we determined the levels of macaque and rabbit mtDNAs in macaque embryos reprogrammed by rabbit oocytes. Quantification using a real-time PCR method showed that both macaque and rabbit mtDNAs coexist in NT embryos at all preimplantation stages, with maternal mtDNA being dominant. Single NT embryos at the 1-cell stage immediately after fusion contained 2.6 x 10(4) copies of macaque mtDNA and 1.3 x 10(6) copies of rabbit mtDNA. Copy numbers of both mtDNA species did not change significantly from the 1-cell to the morula stages. In the single blastocyst, however, the number of rabbit mtDNA increased dramatically while macaque mtDNA decreased. The ratio of nuclear donor mtDNA to oocyte mtDNA dropped sharply from 2% at the 1-cell stage to 0.011% at the blastocyst stage. These results suggest that maternal mtDNA replicates after the morula stage.
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, 25 Bei Si Huan Xi Lu, Haidian, Beijing 100080, China.
authors.forename: Cai-Xia
authors.initials: CX
authors.lastname: Yang
authors.forename: Zhao-Hui
authors.initials: ZH
authors.lastname: Kou
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Jiang
authors.forename: Wen-Wei
authors.initials: WW
authors.lastname: Mao
authors.forename: Qing-Yuan
authors.initials: QY
authors.lastname: Sun
authors.forename: Hui-Zhen
authors.initials: HZ
authors.lastname: Sheng
authors.forename: Da-Yuan
authors.initials: DY
authors.lastname: Chen
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000648:ultrastructure; D002970:Cleavage Stage, Ovum / Q000648:ultrastructure; D004272:DNA, Mitochondrial / Q000648:ultrastructure*; D004622:Embryo, Mammalian / Q000648:ultrastructure*; D005260:Female; D008251:Macaca; D009028:Morula / Q000648:ultrastructure; D053652:Nuclear Transfer Techniques; D009865:Oocytes / Q000648:ultrastructure*; D011817:Rabbits; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D004272:DNA, Mitochondrial