title: Mitochondrial DNA heteroplasmy in wheat, Aegilops and their nucleus-cytoplasm hybrids.
abstract: A mitochondrial (mt) transcriptional unit, nad3-orf156, was studied in the nucleus-cytoplasm hybrids of wheat with D/D2 plasmons from Aegilops species and their parental lines. A comparative RFLP analysis and sequencing of the random PCR clones revealed the presence of seven sequence types and their polymorphic sites were mapped. All the hybrids possessed the paternal copies besides the maternal copies. More paternal copies were present in the D2 plasmon hybrids, whereas more maternal copies were present in the D plasmon hybrids. Two major copies were present with different stoichiometries in the maternal Aegilops parents. However, only a major D plasmon copy was detected in the hybrids, irrespective of their plasmon types. The hexaploid wheat parent (AABBDD genome) possessed the major D plasmon copy in approximately 5% stoichiometry, while no D plasmon-homologous copies were detected in the tetraploid wheat parent (AABB genome). The results suggest that the observed mtDNA heteroplasmy is due to paternal contribution of mtDNA. The different copy stoichiometry suggests differential amplification of the heteroplasmic copies among the hybrids and the parental lines. All editing sites and their editing frequencies were conserved among the lines, and only the maternal pattern of editing occurred in the hybrids.
authors.affiliation: Laboratory of Plant Genetics, Department of Biological and Environmental Science, Faculty of Agriculture, and Division of Life Science, Graduate School of Science and Technology, Kobe University, Nada-ku, Kobe 657-8501, Japan.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Hattori
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Kitagawa
authors.forename: Shigeo
authors.initials: S
authors.lastname: Takumi
authors.forename: Chiharu
authors.initials: C
authors.lastname: Nakamura
mesh_terms: D002467:Cell Nucleus / Q000235:genetics*; D004272:DNA, Mitochondrial; D024101:Mitochondrial Proteins; D016366:Open Reading Frames; D010940:Plant Proteins / Q000235:genetics*; D011123:Polyploidy; D017393:RNA Editing; D017422:Sequence Analysis, DNA; D014908:Triticum / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial; D024101:Mitochondrial Proteins; D010940:Plant Proteins