On the evolutionary descent of organisms and organelles: a global phylogeny based on a highly conserved structural core in small subunit ribosomal RNA

• Published in: Nucleic acids research Vol. 12; no. 14; pp. 5837 - 5852
• Main Authors: Gray, Michael W., Sankoff, David, Cedergren, Robert J.
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 25.07.1984
• Subjects: Animals; Base Sequence; Biological Evolution; DNA, Mitochondrial - genetics; Eukaryotic Cells - physiology; Nucleic Acid Conformation; Prokaryotic Cells - physiology; Ribosomes - ultrastructure; RNA, Ribosomal - genetics; Space life sciences
• ISSN: 0305-1048; 1362-4962
• DOI: 10.1093/nar/12.14.5837

To probe the earliest evolutionary events attending the origin of the five known genome types (archaebacterial, eubacterial, nuclear, mitochondrial and plastid), we have analyzed sequences corresponding to a ubiquitous, highly conserved core of secondary structure in small subunit rRNA. Our results support (i) the existence of three primary lineages (archaebacterial, eubacterial, and nuclear), (ii) a specific eubacterial ancestry for plastids and mitochondria (plant, animal, fungal), and (iii) an eadosymbiotic, evolutionary origin of the two types of organelle from within distinct groups of eubacteria (blue-green algae (cyanobacteria) in the case of plastids, nonphotosynthetlc aerobic bacteria in the case of mitochondria). In addition, our analysis suggests (lv) a biphyletic origin of aitochondria, with animal and fungal mitochondria branching together but separately from plant aitochondria, and Cv) a monophyletic origin of plastids. The method described here provides a powerful and generally applicable molecular taxonomic approach towards a global phylogeny encompassing all organisms and organelles.