Abstract
Ever since its discovery, the double-stranded DNA contained in the mitochondria of eukaryotes has fascinated researchers because of its bacterial endosymbiotic origin, crucial role in encoding subunits of the respiratory complexes, compact nature, and specific inheritance mechanisms. In the last few years, high-throughput sequencing techniques have accelerated the sequencing of mitochondrial genomes (mitogenomes) and uncovered the great diversity of organizations, gene contents, and modes of replication and transcription found in living eukaryotes. Some early divergent lineages of unicellular eukaryotes retain certain synteny and gene content resembling those observed in the genomes of alphaproteobacteria (the inferred closest living group of mitochondria), whereas others adapted to anaerobic environments have drastically reduced or even lost the mitogenome. In the three main multicellular lineages of eukaryotes, mitogenomes have pursued diverse evolutionary trajectories in which different types of molecules (circular versus linear and single versus multipartite), gene structures (with or without self-splicing introns), gene contents, gene orders, genetic codes, and transfer RNA editing mechanisms have been selected. Whereas animals have evolved a rather compact mitochondrial genome between 11 and 50 Kb in length with a highly conserved gene content in bilaterians, plants exhibit large mitochondrial genomes of 66 Kb to 11.3 Mb with large intergenic repetitions prone to recombination, and fungal mitogenomes have intermediate sizes of 12 to 236 Kb.
Highlights
Mitochondria are specialized organelles of eukaryotic cells in charge of essential roles, including the supply of energy through aerobic respiration, the biosynthesis of different types of lipids and iron–sulfur clusters, programmed cell death, calcium homeostasis, and the reaction to stressors, among many others[1]
Faculty Reviews are review articles written by the prestigious Members of Faculty Opinions
All mitochondria descend from an ancestor related to extant alphaproteobacteria[4] which integrated into a host cell related to extant Asgard archaea[5]
Summary
Faculty Reviews are review articles written by the prestigious Members of Faculty Opinions. The articles are commissioned and peer reviewed before publication to ensure that the final, published version is comprehensive and accessible. The reviewers who approved the final version are listed with their names and affiliations. 2. Anna Klucnika, Wellcome Trust/Cancer Research UK Gurdon Institute, Cambridge, UK University of Cambridge, Cambridge, UK Hansong Ma, Wellcome Trust/Cancer Research UK Gurdon Institute, Cambridge, UK University of Cambridge, Cambridge, UK. Any comments on the article can be found at the end of the article
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