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Lahr DJG, Kosakyan A, Lara E, Mitchell EAD, Morais L, Porfirio-Sousa AL, Ribeiro GM, Tice AK, Pánek T, Kang S, Brown MW. Phylogenomics and Morphological Reconstruction of Arcellinida Testate Amoebae Highlight Diversity of Microbial Eukaryotes in the Neoproterozoic. Curr Biol 2019; 29:991-1001.e3. [PMID: 30827918 DOI: 10.1016/j.cub.2019.01.078] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 10/26/2018] [Accepted: 01/30/2019] [Indexed: 11/26/2022]
Abstract
Life was microbial for the majority of Earth's history, but as very few microbial lineages leave a fossil record, the Precambrian evolution of life remains shrouded in mystery. Shelled (testate) amoebae stand out as an exception with rich documented diversity in the Neoproterozoic as vase-shaped microfossils (VSMs). While there is general consensus that most of these can be attributed to the Arcellinida lineage in Amoebozoa, it is still unclear whether they can be used as key fossils for interpretation of early eukaryotic evolution. Here, we present a well-resolved phylogenomic reconstruction based on 250 genes, obtained using single-cell transcriptomic techniques from a representative selection of 19 Arcellinid testate amoeba taxa. The robust phylogenetic framework enables deeper interpretations of evolution in this lineage and demanded an updated classification of the group. Additionally, we performed reconstruction of ancestral morphologies, yielding hypothetical ancestors remarkably similar to existing Neoproterozoic VSMs. We demonstrate that major lineages of testate amoebae were already diversified before the Sturtian glaciation (720 mya), supporting the hypothesis that massive eukaryotic diversification took place in the early Neoproterozoic and congruent with the interpretation that VSM are arcellinid testate amoebae.
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Affiliation(s)
- Daniel J G Lahr
- Department of Zoology, Institute of Biosciences, University of São Paulo, Brazil.
| | - Anush Kosakyan
- Department of Zoology, Institute of Biosciences, University of São Paulo, Brazil; Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 1160/31, 37005, České Budějovice, Czech Republic
| | - Enrique Lara
- Real Jardín Botánico, CSIC, Plaza Murillo 2, ES 28014 Madrid, Spain; Laboratory of Soil Biodiversity, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Edward A D Mitchell
- Laboratory of Soil Biodiversity, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland; Botanical Garden of Neuchâtel, Pertuis-du-Sault 58, 2000 Neuchâtel, Switzerland
| | - Luana Morais
- Department of Geophysics, Institute of Astronomy, Geophysics and Atmospheric Sciences, University of São Paulo, Brazil
| | | | - Giulia M Ribeiro
- Department of Zoology, Institute of Biosciences, University of São Paulo, Brazil
| | - Alexander K Tice
- Department of Biological Sciences, Mississippi State University, Starkville, MS, USA; Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Starkville, MS, USA
| | - Tomáš Pánek
- Department of Biological Sciences, Mississippi State University, Starkville, MS, USA; Department of Biology and Ecology, Faculty of Science, University of Ostrava, Czech Republic
| | - Seungho Kang
- Department of Biological Sciences, Mississippi State University, Starkville, MS, USA; Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Starkville, MS, USA
| | - Matthew W Brown
- Department of Biological Sciences, Mississippi State University, Starkville, MS, USA; Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Starkville, MS, USA.
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Oliverio AM, Lahr DJG, Grant J, Katz LA. Are microbes fundamentally different than macroorganisms? Convergence and a possible case for neutral phenotypic evolution in testate amoeba (Amoebozoa: Arcellinida). R Soc Open Sci 2015; 2:150414. [PMID: 27019725 PMCID: PMC4807447 DOI: 10.1098/rsos.150414] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 11/17/2015] [Indexed: 06/05/2023]
Abstract
This study reveals extensive phenotypic convergence based on the non-monophyly of genera and morphospecies of testate (shelled) amoebae. Using two independent markers, small subunit ribosomal DNA (ssu-rDNA) and mitochondrial cytochrome oxidase I (COI), we demonstrate discordance between morphology and molecules for 'core Nebela' species (Arcellinida; Amoebozoa). Prior work using just a single locus, ssu-rDNA, also supported the non-monophyly of the genera Hyalosphenia and Nebela as well as for several morphospecies within these genera. Here, we obtained COI gene sequences of 59 specimens from seven morphospecies and ssu-rDNA gene sequences of 50 specimens from six morphospecies of hyalosphenids. Our analyses corroborate the prior ssu-rDNA findings of morphological convergence in test (shell) morphologies, as COI and ssu-rDNA phylogenies are concordant. Further, the monophyly of morphospecies is rejected using approximately unbiased tests. Given that testate amoebae are used as bioindicators in both palaeoecological and contemporary studies of threatened ecosystems such as bogs and fens, understanding the discordance between morphology and genetics in the hyalosphenids is essential for interpretation of indicator species. Further, while convergence is normally considered the result of natural selection, it is possible that neutrality underlies phenotypic evolution in these microorganisms.
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Affiliation(s)
- Angela M. Oliverio
- Department of Biological Sciences, Smith College, Northampton, MA 01063, USA
| | - Daniel J. G. Lahr
- Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo 05508-090, Brazil
| | - Jessica Grant
- Department of Biological Sciences, Smith College, Northampton, MA 01063, USA
| | - Laura A. Katz
- Department of Biological Sciences, Smith College, Northampton, MA 01063, USA
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA 01003, USA
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