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The Syntrophy hypothesis for the origin of eukaryotes revisited

Abstract

The discovery of Asgard archaea, phylogenetically closer to eukaryotes than other archaea, together with improved knowledge of microbial ecology, impose new constraints on emerging models for the origin of the eukaryotic cell (eukaryogenesis). Long-held views are metamorphosing in favour of symbiogenetic models based on metabolic interactions between archaea and bacteria. These include the classical Searcy’s and Hydrogen hypothesis, and the more recent Reverse Flow and Entangle–Engulf–Endogenize models. Two decades ago, we put forward the Syntrophy hypothesis for the origin of eukaryotes based on a tripartite metabolic symbiosis involving a methanogenic archaeon (future nucleus), a fermentative myxobacterial-like deltaproteobacterium (future eukaryotic cytoplasm) and a metabolically versatile methanotrophic alphaproteobacterium (future mitochondrion). A refined version later proposed the evolution of the endomembrane and nuclear membrane system by invagination of the deltaproteobacterial membrane. Here, we adapt the Syntrophy hypothesis to contemporary knowledge, shifting from the original hydrogen and methane-transfer-based symbiosis (HM Syntrophy) to a tripartite hydrogen and sulfur-transfer-based model (HS Syntrophy). We propose a sensible ecological scenario for eukaryogenesis in which eukaryotes originated in early Proterozoic microbial mats from the endosymbiosis of a hydrogen-producing Asgard archaeon within a complex sulfate-reducing deltaproteobacterium. Mitochondria evolved from versatile, facultatively aerobic, sulfide-oxidizing and, potentially, anoxygenic photosynthesizing alphaproteobacterial endosymbionts that recycled sulfur in the consortium. The HS Syntrophy hypothesis accounts for (endo)membrane, nucleus and metabolic evolution in a realistic ecological context. We compare and contrast the HS Syntrophy hypothesis to other models of eukaryogenesis, notably in terms of the mode and tempo of eukaryotic trait evolution, and discuss several model predictions and how these can be tested.

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Fig. 1: Environmental context, metabolic interactions and (endo)membrane evolution during eukaryogenesis according to the HS Syntrophy hypothesis.

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References

  1. Adl, S. M. et al. The revised classification of eukaryotes. J. Eukaryot. Microbiol. 59, 429–493 (2012).

    PubMed  PubMed Central  Google Scholar 

  2. Lopez-Garcia, P. & Moreira, D. Open questions on the origin of eukaryotes. Trends Ecol. Evol. 30, 697–708 (2015).

    PubMed  PubMed Central  Google Scholar 

  3. Lopez-Garcia, P., Eme, L. & Moreira, D. Symbiosis in eukaryotic evolution. J. Theor. Biol. 434, 20–33 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  4. Poole, A. M. & Penny, D. Evaluating hypotheses for the origin of eukaryotes. Bioessays 29, 74–84 (2007).

    PubMed  Google Scholar 

  5. de Duve, C. The origin of eukaryotes: a reappraisal. Nat. Rev. Genet. 8, 395–403 (2007).

    PubMed  Google Scholar 

  6. Eme, L., Spang, A., Lombard, J., Stairs, C. W. & Ettema, T. J. G. Archaea and the origin of eukaryotes. Nat. Rev. Microbiol. 15, 711–723 (2017).

    CAS  PubMed  Google Scholar 

  7. Embley, T. M. & Hirt, R. P. Early branching eukaryotes? Curr. Opin. Genet. Dev. 8, 624–629 (1998).

    CAS  PubMed  Google Scholar 

  8. Cox, C. J., Foster, P. G., Hirt, R. P., Harris, S. R. & Embley, T. M. The archaebacterial origin of eukaryotes. Proc. Natl Acad. Sci. USA 105, 20356–20361 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  9. Spang, A. et al. Complex archaea that bridge the gap between prokaryotes and eukaryotes. Nature 521, 173–179 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  10. Zaremba-Niedzwiedzka, K. et al. Asgard archaea illuminate the origin of eukaryotic cellular complexity. Nature 541, 353–358 (2017).

    CAS  PubMed  Google Scholar 

  11. Williams, T. A., Cox, C. J., Foster, P. G., Szöllősi, G. J. & Embley, T. M. Phylogenomics provides robust support for a two-domains tree of life. Nat. Ecol. Evol. 138–147 (2019).

  12. McInerney, J. O., O’Connell, M. J. & Pisani, D. The hybrid nature of the Eukaryota and a consilient view of life on Earth. Nat. Rev. Microbiol. 12, 449–455 (2014).

    CAS  PubMed  Google Scholar 

  13. Koonin, E. V. Archaeal ancestors of eukaryotes: not so elusive any more. BMC Biol. 13, 84 (2015).

    PubMed  PubMed Central  Google Scholar 

  14. Williams, T. A. & Embley, T. M. Changing ideas about eukaryotic origins. Philos. Trans. R. Soc. Lond. B 370, 20140318 (2015).

    Google Scholar 

  15. Libby, E., Hebert-Dufresne, L., Hosseini, S. R. & Wagner, A. Syntrophy emerges spontaneously in complex metabolic systems. PLoS Comput. Biol. 15, e1007169 (2019).

    PubMed  PubMed Central  Google Scholar 

  16. Spang, A. et al. Proposal of the reverse flow model for the origin of the eukaryotic cell based on comparative analyses of Asgard archaeal metabolism. Nat. Microbiol. 4, 1138–1148 (2019).

    CAS  PubMed  Google Scholar 

  17. Lopez-Garcia, P. & Moreira, D. Eukaryogenesis, a syntrophy affair. Nat. Microbiol. 4, 1068–1070 (2019).

    CAS  PubMed  PubMed Central  Google Scholar 

  18. Imachi, H. et al. Isolation of an archaeon at the prokaryote-eukaryote interface. Nature 577, 519–525 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  19. López-García, P. & Moreira, D. Selective forces for the origin of the eukaryotic nucleus. Bioessays 28, 525–533 (2006).

    PubMed  Google Scholar 

  20. Koonin, E. V. & Yutin, N. The dispersed archaeal eukaryome and the complex archaeal ancestor of eukaryotes. Cold Spring Harb. Perspect. Biol. 6, a016188 (2014).

    PubMed  PubMed Central  Google Scholar 

  21. Koonin, E. V. Origin of eukaryotes from within archaea, archaeal eukaryome and bursts of gene gain: eukaryogenesis just made easier? Philos. Trans. R. Soc. Lond. B 370, 20140333 (2015).

    Google Scholar 

  22. Sagan, L. On the origin of mitosing cells. J. Theor. Biol. 14, 255–274 (1967).

    CAS  PubMed  Google Scholar 

  23. Margulis, L. Origin of eukaryotic cells (Yale Univ. Press, 1970).

  24. Margulis, L., Dolan, M. F. & Guerrero, R. The chimeric eukaryote: origin of the nucleus from the karyomastigont in amitochondriate protists. Proc. Natl Acad. Sci. USA 97, 6954–6959 (2000).

    CAS  PubMed  PubMed Central  Google Scholar 

  25. Martin, W. & Muller, M. The hydrogen hypothesis for the first eukaryote. Nature 392, 37–41 (1998).

    CAS  PubMed  Google Scholar 

  26. Moreira, D. & López-García, P. Symbiosis between methanogenic archaea and delta-Proteobacteria as the origin of eukaryotes: the syntrophic hypothesis. J. Mol. Evol. 47, 517–530 (1998).

    CAS  PubMed  Google Scholar 

  27. López-García, P. & Moreira, D. Metabolic symbiosis at the origin of eukaryotes. Trends Biochem. Sci. 24, 88–93 (1999).

    PubMed  Google Scholar 

  28. Javaux, E. J. Challenges in evidencing the earliest traces of life. Nature 572, 451–460 (2019).

    CAS  PubMed  Google Scholar 

  29. Eme, L., Sharpe, S. C., Brown, M. W. & Roger, A. J. On the age of eukaryotes: evaluating evidence from fossils and molecular clocks. Cold Spring Harb. Perspect. Biol. 6, a016139 (2014).

    PubMed  PubMed Central  Google Scholar 

  30. Betts, H. C. et al. Integrated genomic and fossil evidence illuminates life’s early evolution and eukaryote origin. Nat. Ecol. Evol. 2, 1556–1562 (2018).

    PubMed  PubMed Central  Google Scholar 

  31. Martijn, J., Vosseberg, J., Guy, L., Offre, P. & Ettema, T. J. G. Deep mitochondrial origin outside the sampled alphaproteobacteria. Nature 557, 101–105 (2018).

    CAS  PubMed  Google Scholar 

  32. Roger, A. J., Munoz-Gomez, S. A. & Kamikawa, R. The origin and diversification of mitochondria. Curr. Biol. 27, R1177–R1192 (2017).

    CAS  PubMed  Google Scholar 

  33. Luo, G. et al. Rapid oxygenation of Earth’s atmosphere 2.33 billion years ago. Sci. Adv. 2, e1600134 (2016).

    PubMed  PubMed Central  Google Scholar 

  34. Knoll, A. H., Bergmann, K. D. & Strauss, J. V. Life: the first two billion years. Philos. Trans. R. Soc. Lond. B 371, 20150493 (2016).

    Google Scholar 

  35. El Albani, A. et al. Organism motility in an oxygenated shallow-marine environment 2.1 billion years ago. Proc. Natl Acad. Sci. USA 116, 3431–3436 (2019).

    CAS  PubMed  PubMed Central  Google Scholar 

  36. Canfield, D. E., Habicht, K. S. & Thamdrup, B. The Archean sulfur cycle and the early history of atmospheric oxygen. Science 288, 658–661 (2000).

    CAS  PubMed  Google Scholar 

  37. Halevy, I., Johnston, D. T. & Schrag, D. P. Explaining the structure of the Archean mass-independent sulfur isotope record. Science 329, 204–207 (2010).

    CAS  PubMed  Google Scholar 

  38. Shen, Y., Knoll, A. H. & Walter, M. R. Evidence for low sulphate and anoxia in a mid-Proterozoic marine basin. Nature 423, 632–635 (2003).

    CAS  PubMed  Google Scholar 

  39. Poulton, S. W., Fralick, P. W. & Canfield, D. E. The transition to a sulphidic ocean approximately 1.84 billion years ago. Nature 431, 173–177 (2004).

    CAS  PubMed  Google Scholar 

  40. Stolper, D. A. & Keller, C. B. A record of deep-ocean dissolved O2 from the oxidation state of iron in submarine basalts. Nature 553, 323 (2018).

    CAS  PubMed  Google Scholar 

  41. Seitz, K. W. et al. Asgard archaea capable of anaerobic hydrocarbon cycling. Nat. Commun. 10, 1822–1822 (2019).

    PubMed  PubMed Central  Google Scholar 

  42. Saghaï, A. et al. Unveiling microbial interactions in stratified mat communities from a warm saline shallow pond. Environ. Microbiol. 19, 2405–2421 (2017).

    PubMed  PubMed Central  Google Scholar 

  43. Bulzu, P. A. et al. Casting light on Asgardarchaeota metabolism in a sunlit microoxic niche. Nat. Microbiol. 4, 1129–1137 (2019).

    CAS  PubMed  Google Scholar 

  44. Hamilton, T. L., Bryant, D. A. & Macalady, J. L. The role of biology in planetary evolution: cyanobacterial primary production in low-oxygen Proterozoic oceans. Environ. Microbiol. 18, 325–340 (2016).

    CAS  PubMed  Google Scholar 

  45. Lenton, T. M. & Daines, S. J. Matworld - the biogeochemical effects of early life on land. New Phytol. 215, 531–537 (2017).

    CAS  PubMed  Google Scholar 

  46. Bolhuis, H., Cretoiu, M. S. & Stal, L. J. Molecular ecology of microbial mats. FEMS Microbiol. Ecol. 90, 335–350 (2014).

    CAS  PubMed  Google Scholar 

  47. Paerl, H. W., Pinckney, J. L. & Steppe, T. F. Cyanobacterial-bacterial mat consortia: examining the functional unit of microbial survival and growth in extreme environments. Environ. Microbiol. 2, 11–26 (2000).

    CAS  PubMed  Google Scholar 

  48. Martiny, J. B., Jones, S. E., Lennon, J. T. & Martiny, A. C. Microbiomes in light of traits: A phylogenetic perspective. Science 350, aac9323 (2015).

    PubMed  Google Scholar 

  49. Gutierrez-Preciado, A. et al. Functional shifts in microbial mats recapitulate early Earth metabolic transitions. Nat. Ecol. Evol. 2, 1700–1708 (2018).

    PubMed  PubMed Central  Google Scholar 

  50. Harris, J. K. et al. Phylogenetic stratigraphy in the Guerrero Negro hypersaline microbial mat. ISME J. 7, 50–60 (2013).

    PubMed  Google Scholar 

  51. Wong, H. L., Smith, D. L., Visscher, P. T. & Burns, B. P. Niche differentiation of bacterial communities at a millimeter scale in Shark Bay microbial mats. Sci. Rep. 5, 15607 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  52. Dombrowski, N., Seitz, K. W., Teske, A. P. & Baker, B. J. Genomic insights into potential interdependencies in microbial hydrocarbon and nutrient cycling in hydrothermal sediments. Microbiome 5, 106 (2017).

    PubMed  PubMed Central  Google Scholar 

  53. Lovley, D. R. Syntrophy goes electric: direct interspecies electron transfer. Annu. Rev. Microbiol. 71, 643–664 (2017).

    CAS  PubMed  Google Scholar 

  54. Fenchel, T. & Finlay, B. J. Ecology and Evolution in Anoxic Worlds (Oxford Univ. Press, 1995).

  55. Lovley, D. R. Happy together: microbial communities that hook up to swap electrons. ISME J. 11, 327–336 (2016).

    PubMed  PubMed Central  Google Scholar 

  56. Mall, A. et al. Reversibility of citrate synthase allows autotrophic growth of a thermophilic bacterium. Science 359, 563–567 (2018).

    CAS  PubMed  Google Scholar 

  57. Krukenberg, V. et al. Candidatus Desulfofervidus auxilii, a hydrogenotrophic sulfate-reducing bacterium involved in the thermophilic anaerobic oxidation of methane. Environ. Microbiol. 18, 3073–3091 (2016).

    CAS  PubMed  Google Scholar 

  58. Oremland, R. S. & Stolz, J. F. The ecology of arsenic. Science 300, 939–944 (2003).

    CAS  PubMed  Google Scholar 

  59. Muyzer, G. & Stams, A. J. The ecology and biotechnology of sulphate-reducing bacteria. Nat. Rev. Microbiol. 6, 441–454 (2008).

    CAS  PubMed  Google Scholar 

  60. Knittel, K. & Boetius, A. Anaerobic oxidation of methane: progress with an unknown process. Annu. Rev. Microbiol. 63, 311–334 (2009).

    CAS  PubMed  Google Scholar 

  61. Hillesland, K. L. et al. Erosion of functional independence early in the evolution of a microbial mutualism. Proc. Natl Acad. Sci. USA 111, 14822–14827 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  62. Hillesland, K. L. & Stahl, D. A. Rapid evolution of stability and productivity at the origin of a microbial mutualism. Proc. Natl Acad. Sci. USA 107, 2124–2129 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  63. Monteil, C. L. et al. Ectosymbiotic bacteria at the origin of magnetoreception in a marine protist. Nat. Microbiol. 4, 1088–1095 (2019).

    CAS  PubMed  PubMed Central  Google Scholar 

  64. Wang, Y., Wegener, G., Hou, J., Wang, F. & Xiao, X. Expanding anaerobic alkane metabolism in the domain of Archaea. Nat. Microbiol. 4, 595–602 (2019).

    CAS  PubMed  Google Scholar 

  65. Shi, T. & Falkowski, P. G. Genome evolution in cyanobacteria: The stable core and the variable shell. Proc. Natl Acad. Sci. USA 105, 2510–2515 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  66. Shih, P. M. et al. Improving the coverage of the cyanobacterial phylum using diversity-driven genome sequencing. Proc. Natl Acad. Sci. USA 110, 1053–1058 (2013).

    CAS  PubMed  Google Scholar 

  67. Martins, M. C. et al. How superoxide reductases and flavodiiron proteins combat oxidative stress in anaerobes. Free Radic. Biol. Med. 140, 36–60 (2019).

    CAS  PubMed  Google Scholar 

  68. Slesak, I., Kula, M., Slesak, H., Miszalski, Z. & Strzalka, K. How to define obligatory anaerobiosis? An evolutionary view on the antioxidant response system and the early stages of the evolution of life on Earth. Free Radic. Biol. Med. 140, 61–73 (2019).

    CAS  PubMed  Google Scholar 

  69. Fischer, W. W., Hemp, J. & Valentine, J. S. How did life survive Earth’s great oxygenation? Curr. Opin. Chem. Biol. 31, 166–178 (2016).

    CAS  PubMed  Google Scholar 

  70. Neubeck, A. & Freund, F. Sulfur chemistry may have paved the way for evolution of antioxidants. Astrobiology (in the press).

  71. Berghuis, B. A. et al. Hydrogenotrophic methanogenesis in archaeal phylum Verstraetearchaeota reveals the shared ancestry of all methanogens. Proc. Natl Acad. Sci. USA 116, 5037–5044 (2019).

    CAS  PubMed  PubMed Central  Google Scholar 

  72. Borrel, G. et al. Wide diversity of methane and short-chain alkane metabolisms in uncultured archaea. Nat. Microbiol. 4, 603–613 (2019).

    CAS  PubMed  PubMed Central  Google Scholar 

  73. Evans, P. N. et al. An evolving view of methane metabolism in the Archaea. Nat. Rev. Microbiol. 17, 219–232 (2019).

    CAS  PubMed  Google Scholar 

  74. McKay, L. J. et al. Co-occurring genomic capacity for anaerobic methane and dissimilatory sulfur metabolisms discovered in the Korarchaeota. Nat. Microbiol. 4, 614–622 (2019).

    CAS  PubMed  Google Scholar 

  75. Pittis, A. A. & Gabaldon, T. Late acquisition of mitochondria by a host with chimaeric prokaryotic ancestry. Nature 531, 101–104 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  76. Canfield, D. E. & Des Marais, D. J. Aerobic sulfate reduction in microbial mats. Science 251, 1471–1473 (1991).

    CAS  PubMed  Google Scholar 

  77. Visscher, P. T. et al. Formation of lithified micritic laminae in modern marine stromatolites (Bahamas): The role of sulfur cycling. Am. Mineral. 83, 1482–1493 (1998).

    CAS  Google Scholar 

  78. Munoz-Gomez, S. A., Wideman, J. G., Roger, A. J. & Slamovits, C. H. The origin of mitochondrial cristae from Alphaproteobacteria. Mol. Biol. Evol. 34, 943–956 (2017).

    CAS  PubMed  Google Scholar 

  79. Cavalier-Smith, T. Predation and eukaryote cell origins: a coevolutionary perspective. Int. J. Biochem. Cell Biol. 41, 307–322 (2009).

    CAS  PubMed  Google Scholar 

  80. Martin, W. F., Garg, S. & Zimorski, V. Endosymbiotic theories for eukaryote origin. Philos. Trans. R. Soc. Lond. B 370, 20140330 (2015).

    Google Scholar 

  81. Martijn, J. & Ettema, T. J. From archaeon to eukaryote: the evolutionary dark ages of the eukaryotic cell. Biochem. Soc. Trans. 41, 451–457 (2013).

    CAS  PubMed  Google Scholar 

  82. von Dohlen, C. D., Kohler, S., Alsop, S. T. & McManus, W. R. Mealybug beta-proteobacterial endosymbionts contain gamma-proteobacterial symbionts. Nature 412, 433–436 (2001).

    Google Scholar 

  83. Sassera, D. et al. ‘Candidatus Midichloria mitochondrii’, an endosymbiont of the tick Ixodes ricinus with a unique intramitochondrial lifestyle. Int. J. Syst. Evol. Microbiol. 56, 2535–2540 (2006).

    CAS  PubMed  Google Scholar 

  84. Wujek, D. E. Intracellular bacteria in the blue-green alga Pleurocapsa minor. Trans. Am. Microscop. Soc. 98, 143–145 (1979).

    Google Scholar 

  85. Larkin, J. M., Henk, M. C. & Burton, S. D. Occurrence of a Thiothrix sp. attached to mayfly larvae and presence of parasitic bacteria in the Thiothrix sp. Appl. Environ. Microbiol. 56, 357–361 (1990).

    CAS  PubMed  PubMed Central  Google Scholar 

  86. Larkin, J. M. & Henk, M. C. Filamentous sulfide-oxidizing bacteria at hydrocarbon seeps of the gulf of Mexico. Microsc. Res. Tech. 33, 23–31 (1996).

    CAS  PubMed  Google Scholar 

  87. Yamaguchi, M. et al. Prokaryote or eukaryote? A unique microorganism from the deep sea. Microscopy 61, 423–431 (2012).

    CAS  Google Scholar 

  88. Shiratori, T., Suzuki, S., Kakizawa, Y. & Ishida, K.-I. Phagocytosis-like cell engulfment by a planctomycete bacterium. Nat. Commun. 10, 5529–5529 (2019).

    PubMed  PubMed Central  Google Scholar 

  89. Heimerl, T. et al. A complex endomembrane system in the archaeon Ignicoccus hospitalis tapped by Nanoarchaeum equitans. Front. Microbiol. 8, 1072 (2017).

    PubMed  PubMed Central  Google Scholar 

  90. Lombard, J., López-García, P. & Moreira, D. The early evolution of lipid membranes and the three domains of life. Nat. Rev. Microbiol. 10, 507–515 (2012).

    CAS  PubMed  Google Scholar 

  91. Jekely, G. Origin and evolution of the self-organizing cytoskeleton in the network of eukaryotic organelles. Cold Spring Harb. Perspect. Biol. 6, a016030 (2014).

    PubMed  PubMed Central  Google Scholar 

  92. Dacks, J. B. & Field, M. C. Evolutionary origins and specialisation of membrane transport. Curr. Opin. Cell Biol. 53, 70–76 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  93. Dey, G., Thattai, M. & Baum, B. On the archaeal origins of eukaryotes and the challenges of inferring phenotype from genotype. Trends Cell Biol. 26, 476–485 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  94. Rout, M. P. & Field, M. C. The evolution of organellar coat complexes and organization of the eukaryotic cell. Annu. Rev. Biochem. 86, 637–657 (2017).

    CAS  PubMed  Google Scholar 

  95. Yutin, N., Wolf, M. Y., Wolf, Y. I. & Koonin, E. V. The origins of phagocytosis and eukaryogenesis. Biol. Direct 4, 9 (2009).

    PubMed  PubMed Central  Google Scholar 

  96. Lombard, J. The multiple evolutionary origins of the eukaryotic N-glycosylation pathway. Biol. Direct 11, 36 (2016).

    PubMed  PubMed Central  Google Scholar 

  97. Tromer, E. C., van Hooff, J. J. E., Kops, G. & Snel, B. Mosaic origin of the eukaryotic kinetochore. Proc. Natl Acad. Sci. USA 116, 12873–12882 (2019).

    CAS  PubMed  PubMed Central  Google Scholar 

  98. Akıl, C. & Robinson, R. C. Genomes of Asgard archaea encode profilins that regulate actin. Nature 562, 439–443 (2018).

    PubMed  Google Scholar 

  99. Klinger, C. M., Spang, A., Dacks, J. B. & Ettema, T. J. Tracing the archaeal origins of eukaryotic membrane-trafficking system building blocks. Mol. Biol. Evol. 33, 1528–1541 (2016).

    CAS  PubMed  Google Scholar 

  100. Jekely, G. Small GTPases and the evolution of the eukaryotic cell. Bioessays 25, 1129–1138 (2003).

    CAS  PubMed  Google Scholar 

  101. Low, H. H. & Lowe, J. A bacterial dynamin-like protein. Nature 444, 766–769 (2006).

    CAS  PubMed  Google Scholar 

  102. Santana-Molina, C., Rivas-Marin, E., Rojas, A. M. & Devos, D. P. Origin and evolution of polycyclic triterpene synthesis. Mol. Biol. Evol. (in the press).

  103. Caforio, A. et al. Converting Escherichia coli into an archaebacterium with a hybrid heterochiral membrane. Proc. Natl Acad. Sci. USA 115, 3704–3709 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  104. Pogozheva, I. D., Tristram-Nagle, S., Mosberg, H. I. & Lomize, A. L. Structural adaptations of proteins to different biological membranes. Biochim. Biophys. Acta 1828, 2592–2608 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  105. Makarova, M. et al. Delineating the rules for structural adaptation of membrane-associated proteins to evolutionary changes in membrane lipidome. Curr. Biol. 30, 367–380 (2020).

    PubMed  PubMed Central  Google Scholar 

  106. Shimada, H. & Yamagishi, A. Stability of heterochiral hybrid membrane made of bacterial sn-G3P lipids and archaeal sn-G1P lipids. Biochem. 50, 4114–4120 (2011).

    CAS  Google Scholar 

  107. Diekmann, Y. & Pereira-Leal, J. B. Evolution of intracellular compartmentalization. Biochem. J. 449, 319–331 (2013).

    CAS  PubMed  Google Scholar 

  108. Greene, S. E. & Komeili, A. Biogenesis and subcellular organization of the magnetosome organelles of magnetotactic bacteria. Curr. Opin. Cell Biol. 24, 490–495 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  109. van Niftrik, L. A. et al. The anammoxosome: an intracytoplasmic compartment in anammox bacteria. FEMS Microbiol. Lett. 233, 7–13 (2004).

    PubMed  Google Scholar 

  110. Jahn, M. T. et al. Shedding light on cell compartmentation in the candidate phylum Poribacteria by high resolution visualisation and transcriptional profiling. Sci. Rep. 6, 35860 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  111. Fuerst, J. A. Intracellular compartmentation in planctomycetes. Annu. Rev. Microbiol. 59, 299–328 (2005).

    CAS  PubMed  Google Scholar 

  112. Katayama, T. et al. Membrane-bounded nucleoid discovered in a cultivated bacterium of the candidate phylum ‘Atribacteria’. Preprint at https://www.biorxiv.org/content/10.1101/728279v1 (2019).

  113. Borgnia, M. J., Subramaniam, S. & Milne, J. L. Three-dimensional imaging of the highly bent architecture of Bdellovibrio bacteriovorus by using cryo-electron tomography. J. Bacteriol. 190, 2588–2596 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  114. Remis, J. P. et al. Bacterial social networks: structure and composition of Myxococcus xanthus outer membrane vesicle chains. Environ. Microbiol. 16, 598–610 (2014).

    CAS  PubMed  Google Scholar 

  115. Naor, A., Lapierre, P., Mevarech, M., Papke, R. T. & Gophna, U. Low species barriers in halophilic archaea and the formation of recombinant hybrids. Curr. Biol. 22, 1444–1448 (2012).

    CAS  PubMed  Google Scholar 

  116. Nudleman, E., Wall, D. & Kaiser, D. Cell-to-cell transfer of bacterial outer membrane lipoproteins. Science 309, 125–127 (2005).

    CAS  PubMed  Google Scholar 

  117. Cao, P. & Wall, D. Direct visualization of a molecular handshake that governs kin recognition and tissue formation in myxobacteria. Nat. Commun. 10, 3073 (2019).

    PubMed  PubMed Central  Google Scholar 

  118. Jakobczak, B., Keilberg, D., Wuichet, K. & Sogaard-Andersen, L. Contact- and protein transfer-dependent stimulation of assembly of the gliding motility machinery in Myxococcus xanthus. PLoS Genet. 11, e1005341 (2015).

    PubMed  PubMed Central  Google Scholar 

  119. Wolgemuth, C. W. & Oster, G. The junctional pore complex and the propulsion of bacterial cells. J. Mol. Microbiol. Biotechnol. 7, 72–77 (2004).

    CAS  PubMed  Google Scholar 

  120. Nan, B. & Zusman, D. R. Uncovering the mystery of gliding motility in the myxobacteria. Annu. Rev. Genet. 45, 21–39 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  121. Munoz-Dorado, J., Marcos-Torres, F. J., Garcia-Bravo, E., Moraleda-Munoz, A. & Perez, J. Myxobacteria: moving, killing, feeding, and surviving together. Front. Microbiol. 7, 781 (2016).

    PubMed  PubMed Central  Google Scholar 

  122. Patron, N. J. & Waller, R. F. Transit peptide diversity and divergence: A global analysis of plastid targeting signals. Bioessays 29, 1048–1058 (2007).

    CAS  PubMed  Google Scholar 

  123. Rogozin, I. B., Carmel, L., Csuros, M. & Koonin, E. V. Origin and evolution of spliceosomal introns. Biol. Direct 7, 11 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  124. Catania, F., Gao, X. & Scofield, D. G. Endogenous mechanisms for the origins of spliceosomal introns. J. Hered. 100, 591–596 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  125. Vosseberg, J. & Snel, B. Domestication of self-splicing introns during eukaryogenesis: the rise of the complex spliceosomal machinery. Biol. Direct 12, 30 (2017).

    PubMed  PubMed Central  Google Scholar 

  126. Martin, W. & Koonin, E. V. Introns and the origin of nucleus-cytosol compartmentalization. Nature 440, 41–45 (2006).

    CAS  PubMed  Google Scholar 

  127. D’Angelo, M. A. Nuclear pore complexes as hubs for gene regulation. Nucleus 9, 142–148 (2018).

    PubMed  PubMed Central  Google Scholar 

  128. Peña, C., Hurt, E. & Panse, V. G. Eukaryotic ribosome assembly, transport and quality control. Nat. Struct. Mol. Biol. 24, 689 (2017).

    PubMed  Google Scholar 

  129. Feng, J. M., Tian, H. F. & Wen, J. F. Origin and evolution of the eukaryotic SSU processome revealed by a comprehensive genomic analysis and implications for the origin of the nucleolus. Genome Biol. Evol. 5, 2255–2267 (2013).

    PubMed  PubMed Central  Google Scholar 

  130. Rivera, M. C., Jain, R., Moore, J. E. & Lake, J. A. Genomic evidence for two functionally distinct gene classes. Proc. Natl Acad. Sci. USA 95, 6239–6244 (1998).

    CAS  PubMed  PubMed Central  Google Scholar 

  131. Pisani, D., Cotton, J. A. & McInerney, J. O. Supertrees disentangle the chimerical origin of eukaryotic genomes. Mol. Biol. Evol. 24, 1752–1760 (2007).

    CAS  PubMed  Google Scholar 

  132. Gabaldon, T. & Huynen, M. A. From endosymbiont to host-controlled organelle: the hijacking of mitochondrial protein synthesis and metabolism. PLoS Comput. Biol. 3, e219 (2007).

    PubMed  PubMed Central  Google Scholar 

  133. Gabaldon, T. Relative timing of mitochondrial endosymbiosis and the “pre-mitochondrial symbioses” hypothesis. IUBMB Life 70, 1188–1196 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  134. Ku, C. et al. Endosymbiotic gene transfer from prokaryotic pangenomes: Inherited chimerism in eukaryotes. Proc. Natl Acad. Sci. USA 112, 10139–10146 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  135. López-García, P., Zivanovic, Y., Deschamps, P. & Moreira, D. Bacterial gene import and mesophilic adaptation in archaea. Nat. Rev. Microbiol. 13, 447–456 (2015).

    PubMed  PubMed Central  Google Scholar 

  136. Larkum, A. W., Lockhart, P. J. & Howe, C. J. Shopping for plastids. Trends Plant. Sci. 12, 189–195 (2007).

    CAS  PubMed  Google Scholar 

  137. Philippe, H. et al. Comparison of molecular and paleontological data in diatoms suggests a major gap in the fossil record. J. Evol. Biol. 7, 247–265 (1994).

    Google Scholar 

  138. Zhu, S. Evidence for myxobacterial origin of eukaryotic defensins. Immunogenetics 59, 949–954 (2007).

    CAS  PubMed  Google Scholar 

  139. Perez, J., Castaneda-Garcia, A., Jenke-Kodama, H., Muller, R. & Munoz-Dorado, J. Eukaryotic-like protein kinases in the prokaryotes and the myxobacterial kinome. Proc. Natl Acad. Sci. USA 105, 15950–15955 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  140. Kerk, D., Uhrig, R. G., Moorhead, G. B. & Bacterial-like, P. P. P. protein phosphatases: novel sequence alterations in pathogenic eukaryotes and peculiar features of bacterial sequence similarity. Plant Signal. Behav. 8, e27365 (2013).

    PubMed  PubMed Central  Google Scholar 

  141. Elias-Arnanz, M., Padmanabhan, S. & Murillo, F. J. The regulatory action of the myxobacterial CarD/CarG complex: a bacterial enhanceosome? FEMS Microbiol. Rev. 34, 764–778 (2010).

    CAS  PubMed  Google Scholar 

  142. Bock, T., Kasten, J., Muller, R. & Blankenfeldt, W. Crystal structure of the HMG-CoA synthase MvaS from the gram-negative bacterium Myxococcus xanthus. Chembiochem. 17, 1257–1262 (2016).

    CAS  PubMed  Google Scholar 

  143. Osborn, A. R. et al. Evolution and distribution of C7-cyclitol synthases in prokaryotes and eukaryotes. ACS Chem. Biol. 12, 979–988 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  144. Pereto, J., Lopez-Garcia, P. & Moreira, D. Phylogenetic analysis of eukaryotic thiolases suggests multiple proteobacterial origins. J. Mol. Evol. 61, 65–74 (2005).

    CAS  PubMed  Google Scholar 

  145. Schluter, A., Ruiz-Trillo, I. & Pujol, A. Phylogenomic evidence for a myxococcal contribution to the mitochondrial fatty acid beta-oxidation. PloS ONE 6, e21989 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  146. Stairs, C. W., Leger, M. M. & Roger, A. J. Diversity and origins of anaerobic metabolism in mitochondria and related organelles. Philos. Trans. R. Soc. Lond. B 370, 20140326 (2015).

    Google Scholar 

  147. Baum, D. A. & Baum, B. An inside-out origin for the eukaryotic cell. BMC Biol. 12, 76 (2014).

    PubMed  PubMed Central  Google Scholar 

  148. Sousa, F. L., Neukirchen, S., Allen, J. F., Lane, N. & Martin, W. F. Lokiarchaeon is hydrogen dependent. Nat. Microbiol. 1, 16034 (2016).

    CAS  PubMed  Google Scholar 

  149. Searcy, D. G. in The Origin and Evolution of the Cell (eds Hartman, H. & Matsuno, K.) 47–78 (World Scientific, 1992).

  150. Searcy, D. G. Metabolic integration during the evolutionary origin of mitochondria. Cell Res. 13, 229–238 (2003).

    CAS  PubMed  Google Scholar 

  151. Gould, S. B., Garg, S. G. & Martin, W. F. Bacterial vesicle secretion and the evolutionary origin of the eukaryotic endomembrane system. Trends Microbiol. 24, 525–534 (2016).

    CAS  PubMed  Google Scholar 

  152. Embley, T. M. & Martin, W. Eukaryotic evolution, changes and challenges. Nature 440, 623–630 (2006).

    CAS  PubMed  Google Scholar 

  153. Field, M. C. & Rout, M. P. Pore timing: the evolutionary origins of the nucleus and nuclear pore complex. F1000 Res. 8, 369 (2019).

    Google Scholar 

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Acknowledgements

The authors acknowledge funding from the European Research Council (ERC) grants ProtistWorld (to P.L.-G.; agreement no. 322669) and Plast-Evol (to D.M.; agreement no. 787904), and the French Agence Nationale de la Recherche (to P.L.-G.; grant no. ANR-18-CE02-0013-1).

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P.L.-G. and D.M. conceived and discussed the ideas presented in the manuscript. P.L.-G. wrote the manuscript with critical input from D.M.

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López-García, P., Moreira, D. The Syntrophy hypothesis for the origin of eukaryotes revisited. Nat Microbiol 5, 655–667 (2020). https://doi.org/10.1038/s41564-020-0710-4

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