1
|
Smrzka D, Zwicker J, Schulz-Vogt H, Little CTS, Rieder M, Meister P, Gier S, Peckmann J. Fossilized giant sulfide-oxidizing bacteria from the Devonian Hollard Mound seep deposit, Morocco. GEOBIOLOGY 2024; 22:e12581. [PMID: 38059419 DOI: 10.1111/gbi.12581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 10/22/2023] [Accepted: 11/27/2023] [Indexed: 12/08/2023]
Abstract
The giant sulfide-oxidizing bacteria are particularly prone to preservation in the rock record, and their fossils have been identified in ancient phosphorites, cherts, and carbonates. This study reports putative spherical fossils preserved in the Devonian Hollard Mound hydrocarbon-seep deposit. Based on petrographical, mineralogical, and geochemical evidence the putative microfossils are interpreted as sulfide-oxidizing bacteria similar to the present-day genus Thiomargarita, which is also found at modern hydrocarbon seeps. The morphology, distribution, size, and occurrence of the fossilized cells show a large degree of similarity to their modern counterparts. Some of the spherical fossils adhere to worm tubes analogous to the occurrence of modern Thiomargarita on the tubes of seep-dwelling siboglinid worms. Fluorapatite crystals were identified within the fossilized cell walls, suggesting the intercellular storage of phosphorus analogous to modern Thiomargarita cells. The preservation of large sulfide-oxidizing bacteria was probably linked to changing biogeochemical processes at the Hollard Mound seep or, alternatively, may have been favored by the sulfide-oxidizing bacteria performing nitrate-dependent sulfide oxidation-a process known to induce carbonate precipitation. The presence of sulfide-oxidizing bacteria at a Devonian hydrocarbon seep highlights the similarities of past and present chemosynthesis-based ecosystems and provides valuable insight into the antiquity of biogeochemical processes and element cycling at Phanerozoic seeps.
Collapse
Affiliation(s)
- Daniel Smrzka
- Faculty of Geosciences, Universität Bremen, Bremen, Germany
- MARUM Center for Marine and Environmental Sciences, Bremen, Germany
| | - Jennifer Zwicker
- Institute for Mineralogy und Crystallography, Universität Wien, Wien, Austria
| | - Heide Schulz-Vogt
- Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Rostock, Germany
| | - Crispin T S Little
- School of Earth and Environment, University of Leeds, Leeds, UK
- Life Sciences Department, Natural History Museum, London, UK
| | | | | | - Susanne Gier
- Department of Geology, Universität Wien, Wien, Austria
| | - Jörn Peckmann
- Institute for Geology, Center for Earth System Research and Sustainability, Universität Hamburg, Hamburg, Germany
| |
Collapse
|
2
|
The pathway of sulfide oxidation to octasulfur globules in the cytoplasm of aerobic bacteria. Appl Environ Microbiol 2021; 88:e0194121. [PMID: 34878813 DOI: 10.1128/aem.01941-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sulfur-oxidizing bacteria can oxidize hydrogen sulfide (H2S) to produce sulfur globules. Although the process is common, the pathway is unclear. In recombinant Escherichia coli and wild-type Corynebacterium vitaeruminis DSM20294 with SQR but no enzymes to oxidize zero valence sulfur, SQR oxidized H2S into short-chain inorganic polysulfide (H2Sn, n≥2) and organic polysulfide (RSnH, n≥2), which reacted with each other to form long-chain GSnH (n≥2) and H2Sn before producing octasulfur (S8), the main component of elemental sulfur. GSnH also reacted with GSH to form GSnG (n≥2) and H2S; H2S was again oxidized by SQR. After GSH was depleted, SQR simply oxidized H2S to H2Sn, which spontaneously generated S8. S8 aggregated into sulfur globules in the cytoplasm. The results highlight the process of sulfide oxidation to S8 globules in the bacterial cytoplasm and demonstrate the potential of using heterotrophic bacteria with SQR to convert toxic H2S into relatively benign S8 globules. IMPORTANCE Our results support a process of H2S oxidation to produce octasulfur globules via SQR catalysis and spontaneous reactions in the bacterial cytoplasm. Since the process is an important event in geochemical cycling, a better understanding facilitates further studies and provides theoretical support for using heterotrophic bacteria with SQR to oxidize toxic H2S into sulfur globules for recovery.
Collapse
|
3
|
Carlisle EM, Jobbins M, Pankhania V, Cunningham JA, Donoghue PCJ. Experimental taphonomy of organelles and the fossil record of early eukaryote evolution. SCIENCE ADVANCES 2021; 7:eabe9487. [PMID: 33571133 PMCID: PMC7840124 DOI: 10.1126/sciadv.abe9487] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/07/2020] [Indexed: 06/12/2023]
Abstract
The timing of origin of eukaryotes and the sequence of eukaryogenesis are poorly constrained because their fossil record is difficult to interpret. Claims of fossilized organelles have been discounted on the unsubstantiated perception that they decay too quickly for fossilization. We experimentally characterized the pattern and time scale of decay of nuclei, chloroplasts, and pyrenoids in red and green algae, demonstrating that they persist for many weeks postmortem as physical substrates available for preservation, a time scale consistent with known mechanisms of fossilization. Chloroplasts exhibit greater decay resistance than nuclei; pyrenoids are unlikely to be preserved, but their presence could be inferred from spaces within fossil chloroplasts. Our results are compatible with differential organelle preservation in seed plants. Claims of fossilized organelles in Proterozoic fossils can no longer be dismissed on grounds of plausibility, prompting reinterpretation of the early eukaryotic fossil record and the prospect of a fossil record of eukaryogenesis.
Collapse
Affiliation(s)
- Emily M. Carlisle
- School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | | | - Vanisa Pankhania
- School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | | | | |
Collapse
|
4
|
Nishida H. Factors That Affect the Enlargement of Bacterial Protoplasts and Spheroplasts. Int J Mol Sci 2020; 21:E7131. [PMID: 32992574 PMCID: PMC7582836 DOI: 10.3390/ijms21197131] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/24/2020] [Accepted: 09/25/2020] [Indexed: 11/21/2022] Open
Abstract
Cell enlargement is essential for the microinjection of various substances into bacterial cells. The cell wall (peptidoglycan) inhibits cell enlargement. Thus, bacterial protoplasts/spheroplasts are used for enlargement because they lack cell wall. Though bacterial species that are capable of gene manipulation are limited, procedure for bacterial cell enlargement does not involve any gene manipulation technique. In order to prevent cell wall resynthesis during enlargement of protoplasts/spheroplasts, incubation media are supplemented with inhibitors of peptidoglycan biosynthesis such as penicillin. Moreover, metal ion composition in the incubation medium affects the properties of the plasma membrane. Therefore, in order to generate enlarged cells that are suitable for microinjection, metal ion composition in the medium should be considered. Experiment of bacterial protoplast or spheroplast enlargement is useful for studies on bacterial plasma membrane biosynthesis. In this paper, we have summarized the factors that influence bacterial cell enlargement.
Collapse
Affiliation(s)
- Hiromi Nishida
- Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| |
Collapse
|
5
|
Species-dependent protoplast enlargement involves different types of vacuole generation in bacteria. Sci Rep 2020; 10:8832. [PMID: 32483175 PMCID: PMC7264237 DOI: 10.1038/s41598-020-65759-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Accepted: 03/28/2020] [Indexed: 11/08/2022] Open
Abstract
Vacuole generation occurs frequently during the enlargement of bacterial protoplasts and spheroplasts. Gram-positive Enterococcus faecalis protoplasts and gram-negative Lelliottia amnigena spheroplasts had large and small vacuoles inside the cytoplasm, respectively. Although no vacuoles were found at the early stage of cell enlargement, all enlarged cells used in the microinjection procedures had vacuoles. The plasma membrane of L. amnigena was more flexible than that of E. faecalis. In addition, E. faecalis protoplasts had unique discoidal structures as well as spherical structures in the cytoplasm. Our findings showed that the number of vacuoles increased as the L. amnigena plasma membrane expanded and that the size of vacuoles increased as the E. faecalis plasma membrane expanded, suggesting that bacterial cell enlargement involved vacuole generation. Thus, biosynthesis of the plasma and vacuolar membranes was synchronous with the bacterial cell enlargement. Differences in the plasma membrane flexibility might influence the different types of vacuole generation.
Collapse
|
6
|
Exceptional Preservation of Fungi as H2-Bearing Fluid Inclusions in an Early Quaternary Paleo-Hydrothermal System at Cape Vani, Milos, Greece. MINERALS 2019. [DOI: 10.3390/min9120749] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The production of H2 in hydrothermal systems and subsurface settings is almost exclusively assumed a result of abiotic processes, particularly serpentinization of ultramafic rocks. The origin of H2 in environments not hosted in ultramafic rocks is, as a rule, unjustifiably linked to abiotic processes. Additionally, multiple microbiological processes among both prokaryotes and eukaryotes are known to involve H2-production, of which anaerobic fungi have been put forward as a potential source of H2 in subsurface environments, which is still unconfirmed. Here, we report fungal remains exceptionally preserved as fluid inclusions in hydrothermal quartz from feeder quartz-barite veins from the Cape Vani Fe-Ba-Mn ore on the Greek island of Milos. The inclusions possess filamentous or near-spheroidal morphologies interpreted as remains of fungal hyphae and spores, respectively. They were characterized by microthermometry, Raman spectroscopy, and staining of exposed inclusions with WGA-FITC under fluorescence microscopy. The spheroidal aqueous inclusions interpreted as fungal spores are unique by their coating of Mn-oxide birnessite, and gas phase H2. A biological origin of the H2 resulting from anaerobic fungal respiration is suggested. We propose that biologically produced H2 by micro-eukaryotes is an unrecognized source of H2 in hydrothermal systems that may support communities of H2-dependent prokaryotes.
Collapse
|
7
|
Nishino K, Morita Y, Takahashi S, Okumura M, Shiratani S, Umemura K, Narumi I, Kondo C, Ochiai R, Oshima T, Nishida H. Enlargement of Deinococcus grandis spheroplasts requires Mg 2+ or Ca 2. MICROBIOLOGY-SGM 2018; 164:1361-1371. [PMID: 30222092 DOI: 10.1099/mic.0.000716] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
While the cell wall strictly controls cell size and morphology in bacteria, spheroplasts lack cell walls and can become enlarged in growth medium under optimal conditions. Optimal conditions depend on the bacterial species. We frequently observed extreme enlargement of spheroplasts of the radiation-resistant bacterium Deinococcus grandis in Difco Marine Broth 2216, but not in TGY broth (a commonly used growth medium for Deinococcus). Thorough investigation of media components showed that the presence of Mg2+ or Ca2+ promoted extreme spheroplast enlargement, synthesizing the outer membrane. Our findings strongly suggest that Mg2+ or Ca2+ enlarges spheroplasts, which could change the lipid composition of the spheroplast membrane.
Collapse
Affiliation(s)
- Koki Nishino
- 1Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Yusuke Morita
- 1Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Sawako Takahashi
- 1Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Mai Okumura
- 1Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Shusaku Shiratani
- 1Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Kosuke Umemura
- 1Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Issay Narumi
- 2Radiation Microbiology Laboratory, Department of Life Sciences, Faculty of Life Sciences, Toyo University, 1-1-1 Izumino, Gunma 374-0193, Japan
| | - Chie Kondo
- 3Pharmaceuticals and Life Sciences Division, Shimadzu Techno-Research, Inc., 1 Nishinokyoushimoaicho, Nakagyouku, Kyoto 604-8436, Japan
| | - Ryosuke Ochiai
- 3Pharmaceuticals and Life Sciences Division, Shimadzu Techno-Research, Inc., 1 Nishinokyoushimoaicho, Nakagyouku, Kyoto 604-8436, Japan
| | - Taku Oshima
- 1Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Hiromi Nishida
- 1Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| |
Collapse
|
8
|
Crosby CH, Bailey JV. Experimental precipitation of apatite pseudofossils resembling fossil embryos. GEOBIOLOGY 2018; 16:80-87. [PMID: 29047205 DOI: 10.1111/gbi.12264] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 09/10/2017] [Indexed: 06/07/2023]
Abstract
Certain phosphatic grains preserved in the rock record are interpreted as microfossils representing a diversity of microorganisms from bacteria to fossil embryos. In addition to bona fide primary biological features, phosphatic microfossils and fossil embryos commonly exhibit features that result from abiotic precipitation or diagenetic alteration. Distinguishing between abiotic and primary biological features can be difficult, and some features thought to represent biological tissue could instead be artifacts that are unrelated to the original morphology of a preserved organism. Here, we present experimentally generated, abiotically produced mineral precipitates that morphologically resemble biologically produced features, some of which may be observed in the rock record or noted in extant organisms, including embryos. These findings extend the diversity of biomorphic features known to result from abiotic precipitation.
Collapse
Affiliation(s)
- C H Crosby
- Department of Earth Sciences, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - J V Bailey
- Department of Earth Sciences, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| |
Collapse
|
9
|
Abstract
This paper addresses the taphonomic processes responsible for fossil preservation in calcium phosphate, or phosphatization. Aside from silicification and rarer examples of carbonaceous compression, phosphatization is the only taphonomic mode claimed to preserve putative subcellular structures. Because this fossilization window can record such valuable information, a comprehensive understanding of its patterns of occurrence and the geochemical processes involved in the replication of soft tissues are critical endeavors. Fossil phosphatization was most abundant during the latest Neoproterozoic through the early Paleozoic, coinciding with the decline of non-pelletal phosphorite deposits. Its temporal abundance during this timeframe makes it a particularly valuable window for the study of early animal evolution. Several occurrences of phosphatization from the Ediacaran through the Permian Period, including Doushantuo-type preservation of embryo-like fossils and acritarchs, phosphatized gut tracts within Burgess Shale-type carbonaceous compressions, Orsten-type preservation of meiofaunas, and other cases from the later Paleozoic are reviewed. In addition, a comprehensive description of the geochemical controls of calcium phosphate precipitation from seawater is provided, with a focus on the rates of phosphate nucleation and growth, favorable nucleation substrates, and properties of substrate tissue and pore-fluid chemistry. It is hoped that the paleontological and geochemical summaries provided here offer a practical and valuable guide to the Neoproterozoic–Paleozoic phosphatization window.
Collapse
|
10
|
Abstract
The exceptionally preserved fossil record of soft tissues sheds light on a wide range of evolutionary episodes from across geological history. Understanding how soft tissues become hard fossils is not a trivial process. A powerful tool in this context is experimentally derived decay data. By studying decay in a laboratory setting and on a laboratory timescale, an understanding of the processes and patterns underlying soft-tissue preservation can be achieved. The considerations and problems particular to experimental decay are explored here in terms of experimental aims, design, variables, and utility. Aims in this context can relate to either reconstruction of the processes of soft-tissue preservation, or to elucidation of the patterns of morphological transformation and data loss occurring during decay. Experimental design is discussed in terms of hypotheses and relevant variables: i.e., the subject organism being decayed (phylogeny, ontogeny, and history), the environment of decay (biological, chemical, and physical) and the outputs (how to measure decay). Variables and practical considerations are illustrated with reference to previous experiments. The principles behind application of experimentally derived decay data to the fossil record are illustrated with three case studies: the interpretation of fossil color, feasibility of fossil embryos, and phylogenetic bias in chordate preservation. A rich array of possibilities for further decay experiments exists and it is hoped that the methodologies outlined herein will provide guidance and a conceptual framework for future studies.
Collapse
|
11
|
Cunningham JA, Vargas K, Marone F, Bengtson S, Donoghue PCJ. A multicellular organism with embedded cell clusters from the Ediacaran Weng'an biota (Doushantuo Formation, South China). Evol Dev 2017; 18:308-316. [PMID: 27870211 PMCID: PMC6849543 DOI: 10.1111/ede.12210] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Three‐dimensional analyses of the early Ediacaran microfossils from the Weng'an biota (Doushantuo Formation) have focused predominantly on multicellular forms that have been interpreted as embryos, and yet they have defied phylogenetic interpretation principally because of absence of evidence from other stages in their life cycle. It is therefore unfortunate that the affinities of the various other Doushantuo microfossils have been neglected. A new conical fossil that is preserved at a cellular level is described here. The fossil contains distinct cell clusters that are characterized and analysed in three dimensions. These clusters are often exposed at the specimen surface, and the fossil preserves many hemispherical craters that are interpreted as positions where clusters have left the organism. The cell clusters may be either reproductive propagules or infesting organisms. Similar clusters are found in a variety of Doushantuo organisms including putative animal embryos and algae.
Collapse
Affiliation(s)
- John A Cunningham
- Department of Palaeobiology and Nordic Center for Earth Evolution, Swedish Museum of Natural History, Stockholm 10405, Sweden.,School of Earth Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, England
| | - Kelly Vargas
- School of Earth Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, England
| | - Federica Marone
- Swiss Light Source, Paul Scherrer Institute, Villigen 5232, Switzerland
| | - Stefan Bengtson
- Department of Palaeobiology and Nordic Center for Earth Evolution, Swedish Museum of Natural History, Stockholm 10405, Sweden
| | - Philip C J Donoghue
- School of Earth Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, England
| |
Collapse
|
12
|
Three-dimensional preservation of cellular and subcellular structures suggests 1.6 billion-year-old crown-group red algae. PLoS Biol 2017; 15:e2000735. [PMID: 28291791 PMCID: PMC5349422 DOI: 10.1371/journal.pbio.2000735] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 02/07/2017] [Indexed: 01/10/2023] Open
Abstract
The ~1.6 Ga Tirohan Dolomite of the Lower Vindhyan in central India contains phosphatized stromatolitic microbialites. We report from there uniquely well-preserved fossils interpreted as probable crown-group rhodophytes (red algae). The filamentous form Rafatazmia chitrakootensis n. gen, n. sp. has uniserial rows of large cells and grows through diffusely distributed septation. Each cell has a centrally suspended, conspicuous rhomboidal disk interpreted as a pyrenoid. The septa between the cells have central structures that may represent pit connections and pit plugs. Another filamentous form, Denaricion mendax n. gen., n. sp., has coin-like cells reminiscent of those in large sulfur-oxidizing bacteria but much more recalcitrant than the liquid-vacuole-filled cells of the latter. There are also resemblances with oscillatoriacean cyanobacteria, although cell volumes in the latter are much smaller. The wider affinities of Denaricion are uncertain. Ramathallus lobatus n. gen., n. sp. is a lobate sessile alga with pseudoparenchymatous thallus, “cell fountains,” and apical growth, suggesting florideophycean affinity. If these inferences are correct, Rafatazmia and Ramathallus represent crown-group multicellular rhodophytes, antedating the oldest previously accepted red alga in the fossil record by about 400 million years. The last common ancestor of modern eukaryotes is generally believed to have lived during the Mesoproterozoic era, about 1.6 to 1 billion years ago, or possibly somewhat earlier. We studied exquisitely preserved fossil communities from ~1.6 billion-year-old sedimentary rocks in central India representing a shallow-water marine environment characterized by photosynthetic biomats. We discovered amidst extensive cyanobacterial mats a biota of filamentous and lobate organisms that share significant features with modern eukaryotic algae, more specifically red algae. The rocks mainly consist of calcium and magnesium carbonates, but the microbial mats and the fossils are preserved in calcium phosphate, letting us view the cellular and subcellular structures in three dimensions with the use of synchrotron-radiation X-ray tomographic microscopy. The most conspicuous internal objects in the cells of the filamentous forms are rhomboidal platelets that we interpret to be part of the photosynthetic machinery of red algae. The lobate forms grew as radiating globular or finger-like protrusions from a common centre. These fossils predate the previously earliest accepted red algae by about 400 million years, suggesting that eukaryotes may have a longer history than commonly assumed.
Collapse
|
13
|
Wray GA. Molecular clocks and the early evolution of metazoan nervous systems. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2015.0046. [PMID: 26554040 DOI: 10.1098/rstb.2015.0046] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The timing of early animal evolution remains poorly resolved, yet remains critical for understanding nervous system evolution. Methods for estimating divergence times from sequence data have improved considerably, providing a more refined understanding of key divergences. The best molecular estimates point to the origin of metazoans and bilaterians tens to hundreds of millions of years earlier than their first appearances in the fossil record. Both the molecular and fossil records are compatible, however, with the possibility of tiny, unskeletonized, low energy budget animals during the Proterozoic that had planktonic, benthic, or meiofaunal lifestyles. Such animals would likely have had relatively simple nervous systems equipped primarily to detect food, avoid inhospitable environments and locate mates. The appearance of the first macropredators during the Cambrian would have changed the selective landscape dramatically, likely driving the evolution of complex sense organs, sophisticated sensory processing systems, and diverse effector systems involved in capturing prey and avoiding predation.
Collapse
Affiliation(s)
- Gregory A Wray
- Department of Biology and Center for Genomic and Computational Biology, Duke University, Durham, NC 27708, USA
| |
Collapse
|
14
|
Butler AD, Cunningham JA, Budd GE, Donoghue PCJ. Experimental taphonomy of Artemia reveals the role of endogenous microbes in mediating decay and fossilization. Proc Biol Sci 2016; 282:20150476. [PMID: 25972468 PMCID: PMC4455810 DOI: 10.1098/rspb.2015.0476] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Exceptionally preserved fossils provide major insights into the evolutionary history of life. Microbial activity is thought to play a pivotal role in both the decay of organisms and the preservation of soft tissue in the fossil record, though this has been the subject of very little experimental investigation. To remedy this, we undertook an experimental study of the decay of the brine shrimp Artemia, examining the roles of autolysis, microbial activity, oxygen diffusion and reducing conditions. Our findings indicate that endogenous gut bacteria are the main factor controlling decay. Following gut wall rupture, but prior to cuticle failure, gut-derived microbes spread into the body cavity, consuming tissues and forming biofilms capable of mediating authigenic mineralization, that pseudomorph tissues and structures such as limbs and the haemocoel. These observations explain patterns observed in exceptionally preserved fossil arthropods. For example, guts are preserved relatively frequently, while preservation of other internal anatomy is rare. They also suggest that gut-derived microbes play a key role in the preservation of internal anatomy and that differential preservation between exceptional deposits might be because of factors that control autolysis and microbial activity. The findings also suggest that the evolution of a through gut and its bacterial microflora increased the potential for exceptional fossil preservation in bilaterians, providing one explanation for the extreme rarity of internal preservation in those animals that lack a through gut.
Collapse
Affiliation(s)
- Aodhán D Butler
- School of Earth Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK Department of Earth Sciences, Palaeobiology Programme, Uppsala University, Villavägen 16, 75236 Uppsala, Sweden
| | - John A Cunningham
- School of Earth Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK Department of Palaeobiology and Nordic Centre for Earth Evolution, Swedish Museum of Natural History, 10405 Stockholm, Sweden
| | - Graham E Budd
- Department of Earth Sciences, Palaeobiology Programme, Uppsala University, Villavägen 16, 75236 Uppsala, Sweden
| | - Philip C J Donoghue
- School of Earth Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| |
Collapse
|
15
|
Tomescu AMF, Klymiuk AA, Matsunaga KKS, Bippus AC, Shelton GWK. Microbes and the Fossil Record: Selected Topics in Paleomicrobiology. THEIR WORLD: A DIVERSITY OF MICROBIAL ENVIRONMENTS 2016. [DOI: 10.1007/978-3-319-28071-4_3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
16
|
Zatoń M, Broda K. First Record of Soft Tissue Preservation in the Upper Devonian of Poland. PLoS One 2015; 10:e0142619. [PMID: 26559060 PMCID: PMC4641730 DOI: 10.1371/journal.pone.0142619] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Accepted: 10/23/2015] [Indexed: 11/26/2022] Open
Abstract
Soft tissue preservation is reported from Upper Devonian deposits of the Holy Cross Mountains, central Poland, for the first time. The preserved soft tissues are muscles associated with arthropod cuticle fragments. The muscles are phosphatized with variable states of preservation. Well-preserved specimens display the typical banding of striated muscles. Other muscle fragments are highly degraded and/or recrystallized such that their microstructure is barely visible. The phosphatized muscles and associated cuticle are fragmented, occur in patches and some are scattered on the bedding plane. Due to the state of preservation and the lack of diagnostic features, the cuticle identification is problematic; however, it may have belonged to a phyllocarid crustacean. Taphonomic features of the remains indicate that they do not represent fossilized fecal matter (coprolite) but may represent a regurgitate, but the hypothesis is difficult to test. Most probably they represent the leftover remains after arthropod or fish scavenging. The present study shows that soft tissues, which even earlier were manipulated by scavenger, may be preserved if only special microenvironmental conditions within and around the animal remains are established.
Collapse
Affiliation(s)
- Michał Zatoń
- University of Silesia, Faculty of Earth Sciences, Będzińska 60, Sosnowiec, Poland
- * E-mail:
| | - Krzysztof Broda
- University of Silesia, Faculty of Earth Sciences, Będzińska 60, Sosnowiec, Poland
| |
Collapse
|
17
|
Bernard S, Benzerara K, Beyssac O, Balan E, Brown GE. Evolution of the macromolecular structure of sporopollenin during thermal degradation. Heliyon 2015; 1:e00034. [PMID: 27123494 PMCID: PMC4832518 DOI: 10.1016/j.heliyon.2015.e00034] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 08/28/2015] [Accepted: 09/25/2015] [Indexed: 11/13/2022] Open
Abstract
Reconstructing the original biogeochemistry of organic microfossils requires quantifying the extent of the chemical transformations they experienced during burial and maturation processes. In the present study, fossilization experiments have been performed using modern sporopollenin chosen as an analogue for the resistant biocompounds possibly constituting the wall of many organic microfossils. Sporopollenin powder has been processed thermally under argon atmosphere at different temperatures (up to 1000 °C) for varying durations (up to 900 min). Solid residues of each experiment have been characterized using infrared, Raman and synchrotron-based XANES spectroscopies. Results indicate that significant defunctionalisation and aromatization affect the molecular structure of sporopollenin with increasing temperature. Two distinct stages of evolution with temperature are observed: in a first stage, sporopollenin experiences dehydrogenation and deoxygenation simultaneously (below 500 °C); in a second stage (above 500 °C) an increasing concentration in aromatic groups and a lateral growth of aromatic layers are observed. With increasing heating duration (up to 900 min) at a constant temperature (360 °C), oxygen is progressively lost and conjugated carbon–carbon chains or domains grow progressively, following a log-linear kinetic behavior. Based on the comparison with natural spores fossilized within metasediments which experienced intense metamorphism, we show that the present experimental simulations may not perfectly mimic natural diagenesis and metamorphism. Yet, performing such laboratory experiments provides key insights on the processes transforming biogenic molecules into molecular fossils.
Collapse
Affiliation(s)
- S Bernard
- Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie (IMPMC), Sorbonne Universités - MNHN, UPMC Univ Paris 06, CNRS UMR 7590, IRD UMR 206, 75005 Paris, France
| | - K Benzerara
- Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie (IMPMC), Sorbonne Universités - MNHN, UPMC Univ Paris 06, CNRS UMR 7590, IRD UMR 206, 75005 Paris, France
| | - O Beyssac
- Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie (IMPMC), Sorbonne Universités - MNHN, UPMC Univ Paris 06, CNRS UMR 7590, IRD UMR 206, 75005 Paris, France
| | - E Balan
- Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie (IMPMC), Sorbonne Universités - MNHN, UPMC Univ Paris 06, CNRS UMR 7590, IRD UMR 206, 75005 Paris, France
| | - G E Brown
- Surface & Aqueous Geochemistry Group, Department of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305-2115, USA; Department of Photon Science and Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| |
Collapse
|
18
|
Chi Fru E, Ivarsson M, Kilias SP, Frings PJ, Hemmingsson C, Broman C, Bengtson S, Chatzitheodoridis E. Biogenicity of an Early Quaternary iron formation, Milos Island, Greece. GEOBIOLOGY 2015; 13:225-244. [PMID: 25645266 DOI: 10.1111/gbi.12128] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Accepted: 01/05/2015] [Indexed: 06/04/2023]
Abstract
A ~2.0-million-year-old shallow-submarine sedimentary deposit on Milos Island, Greece, harbours an unmetamorphosed fossiliferous iron formation (IF) comparable to Precambrian banded iron formations (BIFs). This Milos IF holds the potential to provide clues to the origin of Precambrian BIFs, relative to biotic and abiotic processes. Here, we combine field stratigraphic observations, stable isotopes of C, S and Si, rock petrography and microfossil evidence from a ~5-m-thick outcrop to track potential biogeochemical processes that may have contributed to the formation of the BIF-type rocks and the abrupt transition to an overlying conglomerate-hosted IF (CIF). Bulk δ(13) C isotopic compositions lower than -25‰ provide evidence for biological contribution by the Calvin and reductive acetyl-CoA carbon fixation cycles to the origin of both the BIF-type and CIF strata. Low S levels of ~0.04 wt.% combined with δ(34) S estimates of up to ~18‰ point to a non-sulphidic depository. Positive δ(30) Si records of up to +0.53‰ in the finely laminated BIF-type rocks indicate chemical deposition on the seafloor during weak periods of arc magmatism. Negative δ(30) Si data are consistent with geological observations suggesting a sudden change to intense arc volcanism potentially terminated the deposition of the BIF-type layer. The typical Precambrian rhythmic rocks of alternating Fe- and Si-rich bands are associated with abundant and spatially distinct microbial fossil assemblages. Together with previously proposed anoxygenic photoferrotrophic iron cycling and low sedimentary N and C potentially connected to diagenetic denitrification, the Milos IF is a biogenic submarine volcano-sedimentary IF showing depositional conditions analogous to Archaean Algoma-type BIFs.
Collapse
Affiliation(s)
- E Chi Fru
- Department of Geological Sciences, Stockholm University, Stockholm, Sweden; Department of Palaeobiology and Nordic Centre for Earth Evolution (NordCEE), Swedish Museum of Natural History, Stockholm, Sweden
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Xiao S, Muscente AD, Chen L, Zhou C, Schiffbauer JD, Wood AD, Polys NF, Yuan X. The Weng'an biota and the Ediacaran radiation of multicellular eukaryotes. Natl Sci Rev 2014. [DOI: 10.1093/nsr/nwu061] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
The rise of multicellularity represents a major evolutionary transition and it occurred independently in multiple eukaryote clades. Although simple multicellular organisms may have evolved in the Mesoproterozoic Era or even earlier, complex multicellular eukaryotes began to diversify only in the Ediacaran Period, just before the Cambrian explosion. Thus, the Ediacaran fossil record can provide key paleontological evidence about the early radiation of multicellular eukaryotes that ultimately culminated in the Cambrian explosion. The Ediacaran Weng'an biota in South China hosts exceptionally preserved eukaryote fossils, including various acanthomorphic acritarchs, pseudoparenchymatous thalli, tubular microfossils, and spheroidal fossils such as Megasphaera, Helicoforamina, Spiralicellula, and Caveasphaera. Many of these fossils have been interpreted as multicellular eukaryotes, although alternative interpretations have also been proposed. In this review, we critically examine these various interpretations, focusing particularly on Megasphaera, which has been variously interpreted as a sulfur-oxidizing bacterium, a unicellular protist, a mesomycetozoean-like holozoan, a volvocine green alga, a stem-group animal, or a crown-group animal. We conclude that Megasphaera is a multicellular eukaryote with evidence for cell-to-cell adhesion, a flexible membrane unconstrained by a rigid cell wall, spatial cellular differentiation, germ–soma separation, and programmed cell death. These features are inconsistent with the bacterium, unicellular protist, and mesomycetozoean-like holozoan interpretations. Thus, the surviving hypotheses, particularly the stem-group animal and algal interpretations, should be further tested with additional evidence. The Weng'an biota also hosts cellularly differentiated pseudoparenchymatous thalli with specialized reproductive structures indicative of an affinity with florideophyte red algae. The other Weng'an fossils reviewed here may also be multicellular eukaryotes, although direct cellular evidence is lacking in some and phylogenetic affinities are poorly constrained in others. The Weng'an biota offers many research opportunities to resolve the life histories and phylogenetic diversity of early multicellular eukaryotes and to illuminate the evolutionary prelude to the Cambrian explosion.
Collapse
Affiliation(s)
- Shuhai Xiao
- Department of Geosciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - A. D. Muscente
- Department of Geosciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Lei Chen
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, Nanjing 210008, China
- College of Earth Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chuanming Zhou
- Key Laboratory of Economic Stratigraphy and Palaeogeography, Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, Nanjing 210008, China
| | - James D. Schiffbauer
- Department of Geological Sciences, University of Missouri, Columbia, MO 65211, USA
| | - Andrew D. Wood
- Advanced Research Computing, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Nicholas F. Polys
- Advanced Research Computing, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Xunlai Yuan
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, Nanjing 210008, China
| |
Collapse
|
20
|
Bailey JV, Corsetti FA, Greene SE, Crosby CH, Liu P, Orphan VJ. Filamentous sulfur bacteria preserved in modern and ancient phosphatic sediments: implications for the role of oxygen and bacteria in phosphogenesis. GEOBIOLOGY 2013; 11:397-405. [PMID: 23786451 DOI: 10.1111/gbi.12046] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 05/24/2013] [Indexed: 06/02/2023]
Abstract
Marine phosphate-rich sedimentary deposits (phosphorites) are important geological reservoirs for the biologically essential nutrient phosphorous. Phosphorites first appear in abundance approximately 600 million years ago, but their proliferation at that time is poorly understood. Recent marine phosphorites spatially correlate with the habitats of vacuolated sulfide-oxidizing bacteria that store polyphosphates under oxic conditions to be utilized under sulfidic conditions. Hydrolysis of the stored polyphosphate results in the rapid precipitation of the phosphate-rich mineral apatite-providing a mechanism to explain the association between modern phosphorites and these bacteria. Whether sulfur bacteria were important to the formation of ancient phosphorites has been unresolved. Here, we present the remains of modern sulfide-oxidizing bacteria that are partially encrusted in apatite, providing evidence that bacterially mediated phosphogenesis can rapidly permineralize sulfide-oxidizing bacteria and perhaps other types of organic remains. We also describe filamentous microfossils that resemble modern sulfide-oxidizing bacteria from two major phosphogenic episodes in the geologic record. These microfossils contain sulfur-rich inclusions that may represent relict sulfur globules, a diagnostic feature of modern sulfide-oxidizing bacteria. These findings suggest that sulfur bacteria, which are known to mediate the precipitation of apatite in modern sediments, were also present in certain phosphogenic settings for at least the last 600 million years. If polyphosphate-utilizing sulfide-oxidizing bacteria also played a role in the formation of ancient phosphorites, their requirements for oxygen, or oxygen-requiring metabolites such as nitrate, might explain the temporal correlation between the first appearance of globally distributed marine phosphorites and increasing oxygenation of Neoproterozoic oceans.
Collapse
Affiliation(s)
- J V Bailey
- Department of Earth Sciences, University of Minnesota- Twin Cities, Minneapolis, MN, USA.
| | | | | | | | | | | |
Collapse
|
21
|
Raff EC, Andrews ME, Turner FR, Toh E, Nelson DE, Raff RA. Contingent interactions among biofilm-forming bacteria determine preservation or decay in the first steps toward fossilization of marine embryos. Evol Dev 2013; 15:243-56. [PMID: 23809699 DOI: 10.1111/ede.12028] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Fossils of soft tissues provide important records of early animals and embryos, and there is substantial evidence for a role for microbes in soft tissue fossilization. We are investigating the initial events in interactions of bacteria with freshly dead tissue, using marine embryos as a model system. We previously found that microbial invasion can stabilize embryo tissue that would otherwise disintegrate in hours or days by generating a bacterial pseudomorph, a three dimensional biofilm that both replaces the tissue and replicates its morphology. In this study, we sampled seawater at different times and places near Sydney, Australia, and determined the range and frequency of different taphonomic outcomes. Although destruction was most common, bacteria in 35% of seawater samples yielded morphology‐preserving biofilms. We could replicate the taphonomic pathways seen with seawater bacterial communities using single cultured strains of marine gammaproteobacteria. Each given species reproducibly generated a consistent taphonomic outcome and we identified species that yielded each of the distinct pathways produced by seawater bacterial communities. Once formed,bacterial pseudomorphs are stable for over a year and resist attack by other bacteria and destruction by proteases and other lytic enzymes. Competition studies showed that the initial action of a pseudomorphing strain can be blocked by a strain that destroys tissues. Thus embryo preservation in nature may depend on contingent interactions among bacterial species that determine if pseudomorphing occurs.We used Artemia nauplius larvae to show that bacterial biofilm replacement of tissue is not restricted to embryos, but is relevant for preservation of small multicellular organisms. We present a model for bacterial self‐assembly of large‐scale three‐dimensional tissue pseudomorphs, based on smallscaleinteractions among individual bacterial cells to form local biofilms at structural boundaries within the tissue. Localbiofilms then conjoin to generate the pseudomorph.
Collapse
Affiliation(s)
- Elizabeth C Raff
- Department of Biology, Indiana University, Bloomington, IN 47405, USA.
| | | | | | | | | | | |
Collapse
|
22
|
Crosby CH, Bailey JV. The role of microbes in the formation of modern and ancient phosphatic mineral deposits. Front Microbiol 2012; 3:241. [PMID: 22783245 PMCID: PMC3389779 DOI: 10.3389/fmicb.2012.00241] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 06/16/2012] [Indexed: 11/13/2022] Open
Abstract
The formation of marine phosphatic mineral deposits remains incompletely understood, despite decades of research. The involvement of bacteria in this process has long been suspected, and both modern and ancient associations between bacteria and phosphorites have been recorded. Only recently has a specific bacterial metabolic process associated with the formation of phosphorites been discovered. Recent studies demonstrate that polyphosphate utilization by sulfide-oxidizing bacteria results in the rapid precipitation of apatite - providing at least a partial mechanism to explain the close spatial correlation between accumulations of sulfide-oxidizing bacteria and modern phosphorites. Possible fossilized bacteria are known from ancient phosphatic mineral deposits. Potentially, the fossilized cells represent the remains of bacteria that induced the formation of those phosphorites. However, robust criteria for the recognition of these bacteria have yet to be identified.
Collapse
Affiliation(s)
- Chris H Crosby
- Department of Earth Sciences, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | | |
Collapse
|
23
|
Cunningham JA, Thomas CW, Bengtson S, Kearns SL, Xiao S, Marone F, Stampanoni M, Donoghue PCJ. Distinguishing geology from biology in the Ediacaran Doushantuo biota relaxes constraints on the timing of the origin of bilaterians. Proc Biol Sci 2012; 279:2369-76. [PMID: 22319125 DOI: 10.1098/rspb.2011.2280] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The Ediacaran Doushantuo biota has yielded fossils that include the oldest widely accepted record of the animal evolutionary lineage, as well as specimens with alleged bilaterian affinity. However, these systematic interpretations are contingent on the presence of key biological structures that have been reinterpreted by some workers as artefacts of diagenetic mineralization. On the basis of chemistry and crystallographic fabric, we characterize and discriminate phases of mineralization that reflect: (i) replication of original biological structure, and (ii) void-filling diagenetic mineralization. The results indicate that all fossils from the Doushantuo assemblage preserve a complex mélange of mineral phases, even where subcellular anatomy appears to be preserved. The findings allow these phases to be distinguished in more controversial fossils, facilitating a critical re-evaluation of the Doushantuo fossil assemblage and its implications as an archive of Ediacaran animal diversity. We find that putative subcellular structures exhibit fabrics consistent with preservation of original morphology. Cells in later developmental stages are not in original configuration and are therefore uninformative concerning gastrulation. Key structures used to identify Doushantuo bilaterians can be dismissed as late diagenetic artefacts. Therefore, when diagenetic mineralization is considered, there is no convincing evidence for bilaterians in the Doushantuo assemblage.
Collapse
Affiliation(s)
- John A Cunningham
- School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK.
| | | | | | | | | | | | | | | |
Collapse
|