Widespread horizontal transfer of mitochondrial genes in flowering plants

• Published in: Nature (London) Vol. 424; no. 6945; pp. 197 - 201
• Main Authors: Bergthorsson, Ulfar, Adams, Keith L., Thomason, Brendan, Palmer, Jeffrey D.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 10.07.2003; Nature Publishing; Nature Publishing Group
• Subjects: Base Sequence; Biological and medical sciences; Botany; Classical genetics, quantitative genetics, hybrids; classification; DNA, Mitochondrial; DNA, Plant; Flowering plants; Flowers & plants; Fundamental and applied biological sciences. Psychology; Gene Transfer, Horizontal; Genes; Genes, Plant; Genetically modified organisms; Genetics; Genetics of eukaryotes. Biological and molecular evolution; Humanities and Social Sciences; introgression; letter; Magnoliopsida; Magnoliopsida - classification; Magnoliopsida - genetics; Mitochondria; Mitochondria - genetics; mitochondrial DNA; Molecular Sequence Data; multidisciplinary; Phylogeny; plant genetics; Plant Proteins; Plant Proteins - genetics; Pteridophyta, spermatophyta; Ribosomal Proteins; Ribosomal Proteins - genetics; Science; Science (multidisciplinary); Vegetals; Mitochondrial DNA; Spermatophyta; Phylogeny; Genetic transfer
• ISSN: 0028-0836; 1476-4687; 1476-4687
• DOI: 10.1038/nature01743

Horizontal gene transfer—the exchange of genes across mating barriers—is recognized as a major force in bacterial evolution 1 , 2 . However, in eukaryotes it is prevalent only in certain phagotrophic protists and limited largely to the ancient acquisition of bacterial genes 3 , 4 , 5 . Although the human genome was initially reported 6 to contain over 100 genes acquired during vertebrate evolution from bacteria, this claim was immediately and repeatedly rebutted 7 , 8 . Moreover, horizontal transfer is unknown within the evolution of animals, plants and fungi except in the special context of mobile genetic elements 9 , 10 , 11 , 12 . Here we show, however, that standard mitochondrial genes, encoding ribosomal and respiratory proteins, are subject to evolutionarily frequent horizontal transfer between distantly related flowering plants. These transfers have created a variety of genomic outcomes, including gene duplication, recapture of genes lost through transfer to the nucleus, and chimaeric, half-monocot, half-dicot genes. These results imply the existence of mechanisms for the delivery of DNA between unrelated plants, indicate that horizontal transfer is also a force in plant nuclear genomes, and are discussed in the contexts of plant molecular phylogeny and genetically modified plants.