title: Dynamic evolution of Geranium mitochondrial genomes through multiple horizontal and intracellular gene transfers.
abstract: The exchange of genetic material between cellular organelles through intracellular gene transfer (IGT) or between species by horizontal gene transfer (HGT) has played an important role in plant mitochondrial genome evolution. The mitochondrial genomes of Geraniaceae display a number of unusual phenomena including highly accelerated rates of synonymous substitutions, extensive gene loss and reduction in RNA editing. Mitochondrial DNA sequences assembled for 17 species of Geranium revealed substantial reduction in gene and intron content relative to the ancestor of the Geranium lineage. Comparative analyses of nuclear transcriptome data suggest that a number of these sequences have been functionally relocated to the nucleus via IGT. Evidence for rampant HGT was detected in several Geranium species containing foreign organellar DNA from diverse eudicots, including many transfers from parasitic plants. One lineage has experienced multiple, independent HGT episodes, many of which occurred within the past 5.5 Myr. Both duplicative and recapture HGT were documented in Geranium lineages. The mitochondrial genome of Geranium brycei contains at least four independent HGT tracts that are absent in its nearest relative. Furthermore, G. brycei mitochondria carry two copies of the cox1 gene that differ in intron content, providing insight into contrasting hypotheses on cox1 intron evolution.
authors.affiliation: Department of Integrative Biology, University of Texas, Austin, TX, 78712, USA.
authors.forename: Seongjun
authors.initials: S
authors.lastname: Park
authors.affiliation: Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE, 68588, USA.
authors.forename: Felix
authors.initials: F
authors.lastname: Grewe
authors.affiliation: Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE, 68588, USA.
authors.forename: Andan
authors.initials: A
authors.lastname: Zhu
authors.affiliation: Department of Integrative Biology, University of Texas, Austin, TX, 78712, USA.
authors.forename: Tracey A
authors.initials: TA
authors.lastname: Ruhlman
authors.affiliation: Department of Biological Science, Biotechnology Research Group, King Abdulaziz University, Jeddah, 21589, Saudi Arabia.
authors.forename: Jamal
authors.initials: J
authors.lastname: Sabir
authors.affiliation: Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE, 68588, USA.
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Mower
authors.affiliation: Department of Integrative Biology, University of Texas, Austin, TX, 78712, USA.|Department of Biological Science, Biotechnology Research Group, King Abdulaziz University, Jeddah, 21589, Saudi Arabia.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Jansen
mesh_terms: D001483:Base Sequence; D004272:DNA, Mitochondrial / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D019143:Evolution, Molecular; D005785:Gene Conversion; D022761:Gene Transfer, Horizontal; D017343:Genes, Plant; D054629:Genome, Mitochondrial; D018745:Genome, Plant; D031315:Geranium / Q000235:genetics*; D042541:Intracellular Space / Q000235:genetics*; D007438:Introns / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D013997:Time Factors
chemical_list: D004272:DNA, Mitochondrial; D018744:DNA, Plant; D003576:Electron Transport Complex IV
keywords: Geraniaceae; cox1 intron; gene conversion; homing endonuclease; multiple organellar genes; parasitic plant