1
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Moroz LL. Brief History of Ctenophora. Methods Mol Biol 2024; 2757:1-26. [PMID: 38668961 DOI: 10.1007/978-1-0716-3642-8_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2024]
Abstract
Ctenophores are the descendants of the earliest surviving lineage of ancestral metazoans, predating the branch leading to sponges (Ctenophore-first phylogeny). Emerging genomic, ultrastructural, cellular, and systemic data indicate that virtually every aspect of ctenophore biology as well as ctenophore development are remarkably different from what is described in representatives of other 32 animal phyla. The outcome of this reconstruction is that most system-level components associated with the ctenophore organization result from convergent evolution. In other words, the ctenophore lineage independently evolved as high animal complexities with the astonishing diversity of cell types and structures as bilaterians and cnidarians. Specifically, neurons, synapses, muscles, mesoderm, through gut, sensory, and integrative systems evolved independently in Ctenophora. Rapid parallel evolution of complex traits is associated with a broad spectrum of unique ctenophore-specific molecular innovations, including alternative toolkits for making an animal. However, the systematic studies of ctenophores are in their infancy, and deciphering their remarkable morphological and functional diversity is one of the hot topics in biological research, with many anticipated surprises.
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Affiliation(s)
- Leonid L Moroz
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA.
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL, USA.
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2
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Anderson RP, Woltz CR, Tosca NJ, Porter SM, Briggs DEG. Fossilisation processes and our reading of animal antiquity. Trends Ecol Evol 2023; 38:1060-1071. [PMID: 37385847 DOI: 10.1016/j.tree.2023.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 05/19/2023] [Accepted: 05/22/2023] [Indexed: 07/01/2023]
Abstract
Estimates for animal antiquity exhibit a significant disconnect between those from molecular clocks, which indicate crown animals evolved ∼800 million years ago (Ma), and those from the fossil record, which extends only ∼574 Ma. Taphonomy is often held culpable: early animals were too small/soft/fragile to fossilise, or the circumstances that preserve them were uncommon in the early Neoproterozoic. We assess this idea by comparing Neoproterozoic fossilisation processes with those of the Cambrian and its abundant animal fossils. Cambrian Burgess Shale-type (BST) preservation captures animals in mudstones showing a narrow range of mineralogies; yet, fossiliferous Neoproterozoic mudstones rarely share the same mineralogy. Animal fossils are absent where BST preservation occurs in deposits ≥789 Ma, suggesting a soft maximum constraint on animal antiquity.
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Affiliation(s)
- Ross P Anderson
- Department of Earth Sciences, University of Oxford, Oxford, OX1 3AN, UK; All Souls College, University of Oxford, Oxford, OX1 4AL, UK.
| | - Christina R Woltz
- Department of Earth Science, University of California at Santa Barbara, Santa Barbara, CA 93106, USA; Department of Earth and Planetary Sciences, Stanford University, Stanford, CA, 94305, USA
| | - Nicholas J Tosca
- Department of Earth Sciences, University of Cambridge, Cambridge, CB2 3EQ, UK
| | - Susannah M Porter
- Department of Earth Science, University of California at Santa Barbara, Santa Barbara, CA 93106, USA
| | - Derek E G Briggs
- Department of Earth and Planetary Sciences, Yale University, New Haven, CT 06511, USA; Yale Peabody Museum, Yale University, New Haven, CT 06520, USA
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3
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Li Y, Dunn FS, Murdock DJE, Guo J, Rahman IA, Cong P. Cambrian stem-group ambulacrarians and the nature of the ancestral deuterostome. Curr Biol 2023:S0960-9822(23)00530-4. [PMID: 37167976 DOI: 10.1016/j.cub.2023.04.048] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 02/17/2023] [Accepted: 04/19/2023] [Indexed: 05/13/2023]
Abstract
Deuterostomes are characterized by some of the most widely divergent body plans in the animal kingdom. These striking morphological differences have hindered efforts to predict ancestral characters, with the origin and earliest evolution of the group remaining ambiguous. Several iconic Cambrian fossils have been suggested to be early deuterostomes and hence could help elucidate ancestral character states. However, their phylogenetic relationships are controversial. Here, we describe new, exceptionally preserved specimens of the discoidal metazoan Rotadiscus grandis from the early Cambrian Chengjiang biota of China. These reveal a previously unknown double spiral structure, which we interpret as a chordate-like covering to a coelomopore, located adjacent to a horseshoe-shaped tentacle complex. The tentacles differ in key aspects from those seen in lophophorates and are instead more similar to the tentacular systems of extant pterobranchs and echinoderms. Thus, Rotadiscus exhibits a chimeric combination of ambulacrarian and chordate characters. Phylogenetic analyses recover Rotadiscus and closely related fossil taxa as stem ambulacrarians, filling a significant morphological gap in the deuterostome tree of life. These results allow us to reconstruct the ancestral body plans of major clades of deuterostomes, revealing that key traits of extant forms, such as a post-anal region, gill bars, and a U-shaped gut, evolved through convergence.
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Affiliation(s)
- Yujing Li
- Yunnan Normal University, Kunming 650500, China; Yunnan Key Laboratory for Palaeobiology & MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Institute of Palaeontology, Yunnan University, Kunming 650500, China; State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Frances S Dunn
- Oxford University Museum of Natural History, University of Oxford, Oxford OX1 3PW, UK
| | - Duncan J E Murdock
- Oxford University Museum of Natural History, University of Oxford, Oxford OX1 3PW, UK
| | - Jin Guo
- Yunnan Key Laboratory for Palaeobiology & MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Institute of Palaeontology, Yunnan University, Kunming 650500, China; Management Committee of the Chengjiang Fossil Site World Heritage, Chengjiang 652599, China
| | - Imran A Rahman
- Oxford University Museum of Natural History, University of Oxford, Oxford OX1 3PW, UK; The Natural History Museum, London SW7 5BD, UK.
| | - Peiyun Cong
- Yunnan Key Laboratory for Palaeobiology & MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Institute of Palaeontology, Yunnan University, Kunming 650500, China.
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4
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Zhao J, Li Y, Selden PA. Two new metazoans from the Cambrian Guanshan biota of China. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2023.1160530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
Abstract
Sessile epibenthos were diverse and played important part in the process of energy flow in the Cambrian marine ecosystem. Based on new specimens from the Gaoloufang Section of the Wulongqing Formation, we describe two new representatives of the group that show character traits with cnidarians and bryozoans. If confirmed, the new material can help us understand the origin and early evolution of these two phyla. The discovery of more sessile epibenthos suggests that the benthic ecosystem of the Guanshan biota (Cambrian Series 2, Stage 4) is more diverse than previously thought.
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5
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Nanglu K, Cole SR, Wright DF, Souto C. Worms and gills, plates and spines: the evolutionary origins and incredible disparity of deuterostomes revealed by fossils, genes, and development. Biol Rev Camb Philos Soc 2023; 98:316-351. [PMID: 36257784 DOI: 10.1111/brv.12908] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 09/23/2022] [Accepted: 09/28/2022] [Indexed: 01/12/2023]
Abstract
Deuterostomes are the major division of animal life which includes sea stars, acorn worms, and humans, among a wide variety of ecologically and morphologically disparate taxa. However, their early evolution is poorly understood, due in part to their disparity, which makes identifying commonalities difficult, as well as their relatively poor early fossil record. Here, we review the available morphological, palaeontological, developmental, and molecular data to establish a framework for exploring the origins of this important and enigmatic group. Recent fossil discoveries strongly support a vermiform ancestor to the group Hemichordata, and a fusiform active swimmer as ancestor to Chordata. The diverse and anatomically bewildering variety of forms among the early echinoderms show evidence of both bilateral and radial symmetry. We consider four characteristics most critical for understanding the form and function of the last common ancestor to Deuterostomia: Hox gene expression patterns, larval morphology, the capacity for biomineralization, and the morphology of the pharyngeal region. We posit a deuterostome last common ancestor with a similar antero-posterior gene regulatory system to that found in modern acorn worms and cephalochordates, a simple planktonic larval form, which was later elaborated in the ambulacrarian lineage, the ability to secrete calcium minerals in a limited fashion, and a pharyngeal respiratory region composed of simple pores. This animal was likely to be motile in adult form, as opposed to the sessile origins that have been historically suggested. Recent debates regarding deuterostome monophyly as well as the wide array of deuterostome-affiliated problematica further suggest the possibility that those features were not only present in the last common ancestor of Deuterostomia, but potentially in the ur-bilaterian. The morphology and development of the early deuterostomes, therefore, underpin some of the most significant questions in the study of metazoan evolution.
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Affiliation(s)
- Karma Nanglu
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, USA
| | - Selina R Cole
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, 10th & Constitution Avenue NW, Washington, DC, 20560, USA.,Sam Noble Museum, University of Oklahoma, 2401 Chautauqua Avenue, Norman, OK, 73072, USA.,School of Geosciences, University of Oklahoma, 100 E Boyd Street, Norman, OK, 73019, USA
| | - David F Wright
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, 10th & Constitution Avenue NW, Washington, DC, 20560, USA.,Sam Noble Museum, University of Oklahoma, 2401 Chautauqua Avenue, Norman, OK, 73072, USA.,School of Geosciences, University of Oklahoma, 100 E Boyd Street, Norman, OK, 73019, USA
| | - Camilla Souto
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, 10th & Constitution Avenue NW, Washington, DC, 20560, USA.,School of Natural Sciences & Mathematics, Stockton University, 101 Vera King Farris Dr, Galloway, NJ, 08205, USA
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6
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Juravel K, Porras L, Höhna S, Pisani D, Wörheide G. Exploring genome gene content and morphological analysis to test recalcitrant nodes in the animal phylogeny. PLoS One 2023; 18:e0282444. [PMID: 36952565 PMCID: PMC10035847 DOI: 10.1371/journal.pone.0282444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 02/14/2023] [Indexed: 03/25/2023] Open
Abstract
An accurate phylogeny of animals is needed to clarify their evolution, ecology, and impact on shaping the biosphere. Although datasets of several hundred thousand amino acids are nowadays routinely used to test phylogenetic hypotheses, key deep nodes in the metazoan tree remain unresolved: the root of animals, the root of Bilateria, and the monophyly of Deuterostomia. Instead of using the standard approach of amino acid datasets, we performed analyses of newly assembled genome gene content and morphological datasets to investigate these recalcitrant nodes in the phylogeny of animals. We explored extensively the choices for assembling the genome gene content dataset and model choices of morphological analyses. Our results are robust to these choices and provide additional insights into the early evolution of animals, they are consistent with sponges as the sister group of all the other animals, the worm-like bilaterian lineage Xenacoelomorpha as the sister group of the other Bilateria, and tentatively support monophyletic Deuterostomia.
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Affiliation(s)
- Ksenia Juravel
- Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, München, Germany
| | - Luis Porras
- Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, München, Germany
| | - Sebastian Höhna
- Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, München, Germany
- GeoBio-Center, Ludwig-Maximilians-Universität München, München, Germany
| | - Davide Pisani
- Bristol Palaeobiology Group, School of Biological Sciences and School of Earth Sciences, University of Bristol, Bristol, United Kingdom
| | - Gert Wörheide
- Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, München, Germany
- GeoBio-Center, Ludwig-Maximilians-Universität München, München, Germany
- SNSB-Bayerische Staatssammlung für Paläontologie und Geologie, München, Germany
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7
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Bauwe H. Photorespiration - Rubisco's repair crew. JOURNAL OF PLANT PHYSIOLOGY 2023; 280:153899. [PMID: 36566670 DOI: 10.1016/j.jplph.2022.153899] [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: 11/15/2022] [Revised: 12/11/2022] [Accepted: 12/11/2022] [Indexed: 06/17/2023]
Abstract
The photorespiratory repair pathway (photorespiration in short) was set up from ancient metabolic modules about three billion years ago in cyanobacteria, the later ancestors of chloroplasts. These prokaryotes developed the capacity for oxygenic photosynthesis, i.e. the use of water as a source of electrons and protons (with O2 as a by-product) for the sunlight-driven synthesis of ATP and NADPH for CO2 fixation in the Calvin cycle. However, the CO2-binding enzyme, ribulose 1,5-bisphosphate carboxylase (known under the acronym Rubisco), is not absolutely selective for CO2 and can also use O2 in a side reaction. It then produces 2-phosphoglycolate (2PG), the accumulation of which would inhibit and potentially stop the Calvin cycle and subsequently photosynthetic electron transport. Photorespiration removes the 2-PG and in this way prevents oxygenic photosynthesis from poisoning itself. In plants, the core of photorespiration consists of ten enzymes distributed over three different types of organelles, requiring interorganellar transport and interaction with several auxiliary enzymes. It goes together with the release and to some extent loss of freshly fixed CO2. This disadvantageous feature can be suppressed by CO2-concentrating mechanisms, such as those that evolved in C4 plants thirty million years ago, which enhance CO2 fixation and reduce 2PG synthesis. Photorespiration itself provided a pioneer variant of such mechanisms in the predecessors of C4 plants, C3-C4 intermediate plants. This article is a review and update particularly on the enzyme components of plant photorespiration and their catalytic mechanisms, on the interaction of photorespiration with other metabolism and on its impact on the evolution of photosynthesis. This focus was chosen because a better knowledge of the enzymes involved and how they are embedded in overall plant metabolism can facilitate the targeted use of the now highly advanced methods of metabolic network modelling and flux analysis. Understanding photorespiration more than before as a process that enables, rather than reduces, plant photosynthesis, will help develop rational strategies for crop improvement.
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Affiliation(s)
- Hermann Bauwe
- University of Rostock, Plant Physiology, Albert-Einstein-Straße 3, D-18051, Rostock, Germany.
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8
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Zhang G, Parry LA, Vinther J, Ma X. Exceptional soft tissue preservation reveals a cnidarian affinity for a Cambrian phosphatic tubicolous enigma. Proc Biol Sci 2022; 289:20221623. [PMID: 36321492 PMCID: PMC9627713 DOI: 10.1098/rspb.2022.1623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Exoskeletal dwelling tubes are widespread among extant animals and early fossil assemblages. Exceptional fossils from the Cambrian reveal independent origins of tube dwelling by several clades including cnidarians, lophophorates, annelids, scalidophorans, panarthropods and ambulacrarians. However, most fossil tubes lack preservation of soft parts, making it difficult to understand their affinities and evolutionary significance. Gangtoucunia aspera (Wulongqing Formation, Cambrian Stage 4) was an annulated, gradually expanding phosphatic tube, with occasional attachments of multiple, smaller juveniles and has previously been interpreted as the dwelling tube of a ‘worm’ (e.g. a scalidophoran), lophophorate or problematicum. Here, we report the first soft tissues from Gangtoucunia that reveal a smooth body with circumoral tentacles and a blind, spacious gut that is partitioned by septa. This is consistent with cnidarian polyps and phylogenetic analysis resolves Gangtoucunia as a total group medusozoan. The tube of Gangtoucunia is phenotypically similar to problematic annulated tubular fossils (e.g. Sphenothallus, Byronia, hyolithelminths), which have been compared to both cnidarians and annelids, and are among the oldest assemblages of skeletal fossils. The cnidarian characters of G. aspera suggest that these early tubular taxa are best interpreted as cnidarians rather than sessile bilaterians in the absence of contrary soft tissue evidence.
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Affiliation(s)
- Guangxu Zhang
- Yunnan Key Laboratory for Palaeobiology and MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Institute of Palaeontology, Yunnan University, Kunming, People's Republic of China
| | - Luke A. Parry
- Department of Earth Sciences, University of Oxford, Oxford, UK
| | - Jakob Vinther
- Schools of Earth Sciences and Biological Sciences, University of Bristol, Bristol, UK
| | - Xiaoya Ma
- Yunnan Key Laboratory for Palaeobiology and MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Institute of Palaeontology, Yunnan University, Kunming, People's Republic of China
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK
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9
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Conway Morris S, Caron JB. A possible home for a bizarre Carboniferous animal: is Typhloesus a pelagic gastropod? Biol Lett 2022; 18:20220179. [PMID: 36126687 PMCID: PMC9489302 DOI: 10.1098/rsbl.2022.0179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
By contrast to many previously enigmatic Palaeozoic fossils, the Carboniferous metazoan Typhloesus has defied phylogenetic placement. Here, we document new features, including possible phosphatized muscle tissues and a hitherto unrecognized feeding apparatus with two sets of ca 20 spinose teeth whose closest similarities appear to lie with the molluscan radula. The ribbon-like structure, located well behind the mouth area and deep into the anterior part of the body, is interpreted as being in an inverted proboscis configuration. Gut contents, mostly conodonts, in the midgut area demonstrate that Typhloesus was an active predator. This animal was capable of propelling itself in the water column using its flexible body and a prominent posterior fin. The affinity of Typhloesus as a pelagic mollusc remains problematic but may lie more closely with the gastropods. Heteropod gastropods share with Typhloesus an active predatory lifestyle and have a comparable general body organization, albeit they possess characteristic aragonitic shells and their origins in the Jurassic post-date Typhloesus. Typhloesus may represent an independent radiation of Mid-Palaeozoic pelagic gastropods.
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Affiliation(s)
- Simon Conway Morris
- Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK
| | - Jean-Bernard Caron
- Department of Natural History, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario, Canada M5S 2C6.,Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S 3B2.,Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto, Ontario, Canada M5S 3B1
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10
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Saleh F, Ma X, Guenser P, Mángano MG, Buatois LA, Antcliffe JB. Probability-based preservational variations within the early Cambrian Chengjiang biota (China). PeerJ 2022; 10:e13869. [PMID: 36032952 PMCID: PMC9415357 DOI: 10.7717/peerj.13869] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 07/19/2022] [Indexed: 01/18/2023] Open
Abstract
The Chengjiang biota (Yunnan Province, China) is a treasure trove of soft-bodied animal fossils from the earliest stages of the Cambrian explosion. The mechanisms contributing to its unique preservation, known as the Burgess Shale-type preservation, are well understood. However, little is known about the preservation differences between various animal groups within this biota. This study compares tissue-occurrence data of 11 major animal groups in the Chengjiang biota using a probabilistic methodology. The fossil-based data from this study is compared to previous decay experiments. This shows that all groups are not equally preserved with some higher taxa more likely to preserve soft tissues than others. These differences in fossil preservation between taxa can be explained by the interaction of biological and environmental characteristics. A bias also results from differential taxonomic recognition, as some taxa are easily recognized from even poorly preserved fragments while other specimens are difficult to assign to higher taxa even with exquisite preservation.
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Affiliation(s)
- Farid Saleh
- MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Yunnan University, Kunming, China,Yunnan Key Laboratory for Palaeobiology, Yunnan University, Kunming, China
| | - Xiaoya Ma
- MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Yunnan University, Kunming, China,Yunnan Key Laboratory for Palaeobiology, Yunnan University, Kunming, China,Centre for Ecology and Conservation, University of Exeter, Penryn, United Kingdom
| | - Pauline Guenser
- University Bordeaux, CNRS, Bordeaux INP, EPOC, UMR5805, Pessac, France
| | - M. Gabriela Mángano
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, Canada
| | - Luis A. Buatois
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, Canada
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11
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Liu Y, Carlisle E, Zhang H, Yang B, Steiner M, Shao T, Duan B, Marone F, Xiao S, Donoghue PCJ. Saccorhytus is an early ecdysozoan and not the earliest deuterostome. Nature 2022; 609:541-546. [PMID: 35978194 DOI: 10.1038/s41586-022-05107-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 07/13/2022] [Indexed: 11/09/2022]
Abstract
The early history of deuterostomes, the group composed of the chordates, echinoderms and hemichordates1, is still controversial, not least because of a paucity of stem representatives of these clades2-5. The early Cambrian microscopic animal Saccorhytus coronarius was interpreted as an early deuterostome on the basis of purported pharyngeal openings, providing evidence for a meiofaunal ancestry6 and an explanation for the temporal mismatch between palaeontological and molecular clock timescales of animal evolution6-8. Here we report new material of S. coronarius, which is reconstructed as a millimetric and ellipsoidal meiobenthic animal with spinose armour and a terminal mouth but no anus. Purported pharyngeal openings in support of the deuterostome hypothesis6 are shown to be taphonomic artefacts. Phylogenetic analyses indicate that S. coronarius belongs to total-group Ecdysozoa, expanding the morphological disparity and ecological diversity of early Cambrian ecdysozoans.
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Affiliation(s)
- Yunhuan Liu
- School of Earth Science and Resources, Chang'an University, Xi'an, China
| | - Emily Carlisle
- Bristol Palaeobiology Group, School of Earth Sciences, University of Bristol, Bristol, UK
| | - Huaqiao Zhang
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing, China.
| | - Ben Yang
- MNR Key Laboratory of Stratigraphy and Palaeontology, Institute of Geology, Chinese Academy of Geological Sciences, Beijing, China
| | - Michael Steiner
- College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao, China.,Department of Earth Sciences, Freie Universität Berlin, Berlin, Germany
| | - Tiequan Shao
- School of Earth Science and Resources, Chang'an University, Xi'an, China
| | - Baichuan Duan
- Key Laboratory of Marine Geology and Metallogeny, First Institute of Oceanography, Ministry of Natural Resource, Qingdao, China
| | - Federica Marone
- Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland
| | - Shuhai Xiao
- Department of Geosciences, Virginia Tech, Blacksburg, VA, USA.
| | - Philip C J Donoghue
- Bristol Palaeobiology Group, School of Earth Sciences, University of Bristol, Bristol, UK.
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12
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Martynov AV, Korshunova TA. Renewed perspectives on the sedentary-pelagic last common bilaterian ancestor. CONTRIBUTIONS TO ZOOLOGY 2022. [DOI: 10.1163/18759866-bja10034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Various evaluations of the last common bilaterian ancestor (lcba) currently suggest that it resembled either a microscopic, non-segmented motile adult; or, on the contrary, a complex segmented adult motile urbilaterian. These fundamental inconsistencies remain largely unexplained. A majority of multidisciplinary data regarding sedentary adult ancestral bilaterian organization is overlooked. The sedentary-pelagic model is supported now by a number of novel developmental, paleontological and molecular phylogenetic data: (1) data in support of sedentary sponges, in the adult stage, as sister to all other Metazoa; (2) a similarity of molecular developmental pathways in both adults and larvae across sedentary sponges, cnidarians, and bilaterians; (3) a cnidarian-bilaterian relationship, including a unique sharing of a bona fide Hox-gene cluster, of which the evolutionary appearance does not connect directly to a bilaterian motile organization; (4) the presence of sedentary and tube-dwelling representatives of the main bilaterian clades in the early Cambrian; (5) an absence of definite taxonomic attribution of Ediacaran taxa reconstructed as motile to any true bilaterian phyla; (6) a similarity of tube morphology (and the clear presence of a protoconch-like apical structure of the Ediacaran sedentary Cloudinidae) among shells of the early Cambrian, and later true bilaterians, such as semi-sedentary hyoliths and motile molluscs; (7) recent data that provide growing evidence for a complex urbilaterian, despite a continuous molecular phylogenetic controversy. The present review compares the main existing models and reconciles the sedentary model of an urbilaterian and the model of a larva-like lcba with a unified sedentary(adult)-pelagic(larva) model of the lcba.
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Affiliation(s)
- Alexander V. Martynov
- Zoological Museum, Moscow State University, Bolshaya Nikitskaya Str. 6, 125009 Moscow, Russia,
| | - Tatiana A. Korshunova
- Koltzov Institute of Developmental Biology RAS, 26 Vavilova Str., 119334 Moscow, Russia
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13
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Dunn FS, Kenchington CG, Parry LA, Clark JW, Kendall RS, Wilby PR. A crown-group cnidarian from the Ediacaran of Charnwood Forest, UK. Nat Ecol Evol 2022; 6:1095-1104. [PMID: 35879540 PMCID: PMC9349040 DOI: 10.1038/s41559-022-01807-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 05/23/2022] [Indexed: 11/17/2022]
Abstract
Cnidarians are a disparate and ancient phylum, encompassing corals and jellyfish, and occupy both the pelagic and benthic realms. They have a rich fossil record from the Phanerozoic eon lending insight into the early history of the group but, although cnidarians diverged from other animals in the Precambrian period, their record from the Ediacaran period (635–542 million years ago) is controversial. Here, we describe a new fossil cnidarian—Auroralumina attenboroughii gen. et sp. nov.—from the Ediacaran of Charnwood Forest (557–562 million years ago) that shows two bifurcating polyps enclosed in a rigid, polyhedral, organic skeleton with evidence of simple, densely packed tentacles. Auroralumina displays a suite of characters allying it to early medusozoans but shows others more typical of Anthozoa. Phylogenetic analyses recover Auroralumina as a stem-group medusozoan and, therefore, the oldest crown-group cnidarian. Auroralumina demonstrates both the establishment of the crown group of an animal phylum and the fixation of its body plan tens of millions of years before the Cambrian diversification of animal life. A new fossil cnidarian, Auroralumina attenboroughi, from the Ediacaran of Charnwood Forest, UK, described as showing mosaic anthozoan and medusozoan characters, is the oldest yet-known crown-group cnidarian.
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Affiliation(s)
- F S Dunn
- Oxford University Museum of Natural History, University of Oxford, Oxford, UK.
| | - C G Kenchington
- Department of Earth Sciences, University of Cambridge, Cambridge, UK
| | - L A Parry
- Department of Earth Sciences, University of Oxford, Oxford, UK
| | - J W Clark
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - R S Kendall
- British Geological Survey, Cardiff University, Cardiff, UK
| | - P R Wilby
- British Geological Survey, Nicker Hill, Keyworth, Nottingham, UK.,Department of Geology, University of Leicester, Leicester, UK
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14
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Retallack GJ. Damaged Dickinsonia specimens provide clues to Ediacaran vendobiont biology. PLoS One 2022; 17:e0269638. [PMID: 35709144 PMCID: PMC9202952 DOI: 10.1371/journal.pone.0269638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 05/19/2022] [Indexed: 12/14/2022] Open
Abstract
Recently reported specimens of the enigmatic Ediacaran fossil Dickinsonia from Russia show damage and repair that provides evidence of how they grew, and of their biological affinities. Marginal and terminal areas of wilting deformation are necrotic zones separating regenerated growth, sometimes on two divergent axes, rather than a single axis. Necrotic zones of damage to Dickinsonia are not a thick scar or callus, like a wound or amputation. Nor are they smooth transitions to a regenerated tail or arm. The wilted necrotic zone is most like damage by freezing, salt, or sunburn of leaves and lichens, compatible with evidence of terrestrial habitat from associated frigid and gypsic paleosols. Dickinsonia did not regrow by postembryonic addition of modules from a subterminal or patterned growth zone as in earthworms, myriapods, trilobites, crustaceans, and lizards. Rather Dickinsonia postembryonic regrowth from sublethal damage was from microscopic apical and lateral meristems, as in plants and lichens. Considered as fungal, Dickinsonia, and perhaps others of Class Vendobionta, were more likely Glomeromycota or Mucoromycotina, rather than Ascomycota or Basidiomycota.
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Affiliation(s)
- Gregory J. Retallack
- Department of Earth Sciences, University of Oregon, Eugene, Oregon, United States of America
- * E-mail:
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15
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Ou Q, Shu D, Zhang Z, Han J, Van Iten H, Cheng M, Sun J, Yao X, Wang R, Mayer G. Dawn of complex animal food webs: A new predatory anthozoan (Cnidaria) from Cambrian. Innovation (N Y) 2022; 3:100195. [PMID: 35005675 PMCID: PMC8717384 DOI: 10.1016/j.xinn.2021.100195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 12/07/2021] [Indexed: 12/03/2022] Open
Abstract
Cnidarians diverged very early in animal evolution; therefore, investigations of the morphology and trophic levels of early fossil cnidarians may provide critical insights into the evolution of metazoans and the origin of modern marine food webs. However, there has been a lack of unambiguous anthozoan cnidarians from Ediacaran assemblages, and undoubted anthozoans from the Cambrian radiation of metazoans are very rare and lacking in ecological evidence. Here, we report a new polypoid cnidarian, Nailiana elegans gen. et sp. nov., represented by multiple solitary specimens from the early Cambrian Chengjiang biota (∼520 Ma) of South China. These specimens show eight unbranched tentacles surrounding a single opening into the gastric cavity, which may have born multiple mesenteries. Thus, N. elegans displays a level of organization similar to that of extant cnidarians. Phylogenetic analyses place N. elegans in the stem lineage of Anthozoa and suggest that the ancestral anthozoan was a soft-bodied, solitary polyp showing octoradial symmetry. Moreover, one specimen of the new polyp preserves evidence of predation on an epifaunal lingulid brachiopod. This case provides the oldest direct evidence of macrophagous predation, the advent of which may have triggered the emergence of complex trophic/ecological relationships in Cambrian marine communities and spurred the explosive radiation of animal body plans. Polypoid animal from early Cambrian of China is a stem-group anthozoan cnidarian Anthozoan ancestor inferred to be soft-bodied, solitary polyp of octoradial symmetry The new anthozoan provides the oldest direct evidence of macrophagous predation Macrophagous predation may have triggered complex food webs in early Cambrian
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Affiliation(s)
- Qiang Ou
- Early Life Evolution Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China.,Department of Zoology, University of Kassel, Kassel 34132, Germany
| | - Degan Shu
- Shaanxi Key Laboratory of Early Life and Environment, State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, China
| | - Zhifei Zhang
- Shaanxi Key Laboratory of Early Life and Environment, State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, China
| | - Jian Han
- Shaanxi Key Laboratory of Early Life and Environment, State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, China
| | - Heyo Van Iten
- Department of Geology, Hanover College, Hanover, IN 47243, USA.,Cincinnati Museum Center, Department of Invertebrate Paleontology, 1301 Western Avenue, Cincinnati, OH 45203, USA
| | - Meirong Cheng
- Shaanxi Key Laboratory of Early Life and Environment, State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, China
| | - Jie Sun
- Shaanxi Key Laboratory of Early Life and Environment, State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, China
| | - Xiaoyong Yao
- School of Earth Science and Resources, Chang'an University, Xi'an 710054, China
| | - Rong Wang
- Early Life Evolution Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China
| | - Georg Mayer
- Department of Zoology, University of Kassel, Kassel 34132, Germany
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16
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Williams EA, Jékely G. Nervous systems: Neuropeptides define enigmatic comb-jelly neurons. Curr Biol 2021; 31:R1515-R1517. [PMID: 34875238 DOI: 10.1016/j.cub.2021.10.054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The apparently simple nerve net of comb-jellies has long intrigued biologists. A new study identifies multiple unique neuropeptides in the comb-jelly nervous system and exploits these as indicators of neuronal identity and morphology.
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Affiliation(s)
- Elizabeth A Williams
- College of Live and Environmental Sciences, Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.
| | - Gáspár Jékely
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.
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17
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Burkhardt P, Jékely G. Evolution of synapses and neurotransmitter systems: The divide-and-conquer model for early neural cell-type evolution. Curr Opin Neurobiol 2021; 71:127-138. [PMID: 34826676 DOI: 10.1016/j.conb.2021.11.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 09/09/2021] [Accepted: 11/02/2021] [Indexed: 01/08/2023]
Abstract
Nervous systems evolved around 560 million years ago to coordinate and empower animal bodies. Ctenophores - one of the earliest-branching lineages - are thought to share a few neuronal genes with bilaterians and may have evolved neurons convergently. Here we review our current understanding of the evolution of neuronal molecules in nonbilaterians. We also reanalyse single-cell sequencing data in light of new cell-cluster identities from a ctenophore and uncover evidence supporting the homology of one ctenophore neuron-type with neurons in Bilateria. The specific coexpression of the presynaptic proteins Unc13 and RIM with voltage-gated channels, neuropeptides and homeobox genes pinpoint a spiking sensory-peptidergic cell in the ctenophore mouth. Similar Unc13-RIM neurons may have been present in the first eumetazoans to rise to dominance only in stem Bilateria. We hypothesise that the Unc13-RIM lineage ancestrally innervated the mouth and conquered other parts of the body with the rise of macrophagy and predation during the Cambrian explosion.
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Affiliation(s)
- Pawel Burkhardt
- Sars International Centre for Marine Molecular Biology, University of Bergen, Norway.
| | - Gáspár Jékely
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, UK.
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18
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Parry LA, Lerosey-Aubril R, Weaver JC, Ortega-Hernández J. Cambrian comb jellies from Utah illuminate the early evolution of nervous and sensory systems in ctenophores. iScience 2021; 24:102943. [PMID: 34522849 PMCID: PMC8426560 DOI: 10.1016/j.isci.2021.102943] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 06/01/2021] [Accepted: 07/30/2021] [Indexed: 12/11/2022] Open
Abstract
Ctenophores are a group of predatory macroinvertebrates whose controversial phylogenetic position has prompted several competing hypotheses regarding the evolution of animal organ systems. Although ctenophores date back at least to the Cambrian, they have a poor fossil record due to their gelatinous bodies. Here, we describe two ctenophore species from the Cambrian of Utah, which illuminate the early evolution of nervous and sensory features in the phylum. Thalassostaphylos elegans has 16 comb rows, an oral skirt, and an apical organ with polar fields. Ctenorhabdotus campanelliformis has 24 comb rows, an oral skirt, an apical organ enclosed by a capsule and neurological tissues preserved as carbonaceous films. These are concentrated around the apical organ and ciliated furrows, which connect to a circumoral nerve ring via longitudinal axons. C. campanelliformis deviates from the neuroanatomy of living ctenophores and demonstrates a substantial complexity in the nervous system of Cambrian ctenophores. Two species of rare fossil ctenophores are described from the Cambrian of Utah Fossil ctenophores preserve remains of nervous tissue and sensory structures Neurological structures include an oral nerve ring and giant longitudinal axons Cambrian ctenophores had a more complex neuroanatomy than living species
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Affiliation(s)
- Luke A Parry
- Department of Earth Sciences, University of Oxford, 3 South Parks Road, Oxford, OX1 3AN, UK.,Department of Geology and Geophysics, Yale University, 210 Whitney Avenue, New Haven, CT 06511, USA
| | - Rudy Lerosey-Aubril
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
| | - James C Weaver
- Wyss Institute for Biologically Inspired Engineering, Harvard University, 60 Oxford Street, Cambridge, MA 02138, USA
| | - Javier Ortega-Hernández
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
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19
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Klug C, Kerr J, Lee MSY, Cloutier R. A late-surviving stem-ctenophore from the Late Devonian of Miguasha (Canada). Sci Rep 2021; 11:19039. [PMID: 34561497 PMCID: PMC8463547 DOI: 10.1038/s41598-021-98362-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 09/06/2021] [Indexed: 11/08/2022] Open
Abstract
Like other soft-bodied organisms, ctenophores (comb jellies) produce fossils only under exceptional taphonomic conditions. Here, we present the first record of a Late Devonian ctenophore from the Escuminac Formation from Miguasha in eastern Canada. Based on the 18-fold symmetry of this disc-shaped fossil, we assign it to the total-group Ctenophora. Our phylogenetic analyses suggest that the new taxon Daihuoides jakobvintheri gen. et sp. nov. falls near Cambrian stem ctenophores such as 'dinomischids' and 'scleroctenophorans'. Accordingly, Daihuoides is a Lazarus-taxon, which post-dates its older relatives by over 140 million years, and overlaps temporally with modern ctenophores, whose oldest representatives are known from the Early Devonian. Our analyses also indicate that the fossil record of ctenophores does not provide strong evidence for or against the phylogenomic hypothesis that ctenophores are sister to all other metazoans.
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Affiliation(s)
- Christian Klug
- Paläontologisches Institut und Museum, Universität Zürich, Karl-Schmid-Strasse 4, 8006, Zurich, Switzerland
| | - Johanne Kerr
- Parc national de Miguasha, 231 Route de Miguasha Ouest, Nouvelle, QC, G0C 2E0, Canada
| | - Michael S Y Lee
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia
- Earth Sciences Section, South Australian Museum, Adelaide, SA, Australia
| | - Richard Cloutier
- Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, 300 allée des Ursulines, Rimouski, QC, G5L 3A1, Canada.
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20
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Dunn FS, Liu AG, Grazhdankin DV, Vixseboxse P, Flannery-Sutherland J, Green E, Harris S, Wilby PR, Donoghue PCJ. The developmental biology of Charnia and the eumetazoan affinity of the Ediacaran rangeomorphs. SCIENCE ADVANCES 2021; 7:eabe0291. [PMID: 34301594 PMCID: PMC8302126 DOI: 10.1126/sciadv.abe0291] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 06/09/2021] [Indexed: 06/13/2023]
Abstract
Molecular timescales estimate that early animal lineages diverged tens of millions of years before their earliest unequivocal fossil evidence. The Ediacaran macrobiota (~574 to 538 million years ago) are largely eschewed from this debate, primarily due to their extreme phylogenetic uncertainty, but remain germane. We characterize the development of Charnia masoni and establish the affinity of rangeomorphs, among the oldest and most enigmatic components of the Ediacaran macrobiota. We provide the first direct evidence for the internal interconnected nature of rangeomorphs and show that Charnia was constructed of repeated branches that derived successively from pre-existing branches. We find homology and rationalize morphogenesis between disparate rangeomorph taxa, before producing a phylogenetic analysis, resolving Charnia as a stem-eumetazoan and expanding the anatomical disparity of that group to include a long-extinct bodyplan. These data bring competing records of early animal evolution into closer agreement, reformulating our understanding of the evolutionary emergence of animal bodyplans.
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Affiliation(s)
- Frances S Dunn
- Oxford University Museum of Natural History, University of Oxford, Parks Road, Oxford OX1 3PW, UK.
- British Geological Survey, Nicker Hill, Keyworth, Nottingham NG12 5GG, UK
- School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Alexander G Liu
- Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK
| | - Dmitriy V Grazhdankin
- Trofimuk Institute of Petroleum Geology and Geophysics, Prospekt Akademika Koptyuga 3, Novosibirsk 630090, Russia
- Novosibirsk State University, Pirogova Street 1, Novosibirsk 630090, Russia
| | - Philip Vixseboxse
- School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Joseph Flannery-Sutherland
- School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Emily Green
- School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Simon Harris
- British Geological Survey, Nicker Hill, Keyworth, Nottingham NG12 5GG, UK
| | - Philip R Wilby
- British Geological Survey, Nicker Hill, Keyworth, Nottingham NG12 5GG, UK
- School of Geography, Geology and the Environment, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - Philip C J Donoghue
- School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
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21
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Jékely G, Godfrey-Smith P, Keijzer F. Reafference and the origin of the self in early nervous system evolution. Philos Trans R Soc Lond B Biol Sci 2021; 376:20190764. [PMID: 33550954 PMCID: PMC7934971 DOI: 10.1098/rstb.2019.0764] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/07/2020] [Indexed: 12/20/2022] Open
Abstract
Discussions of the function of early nervous systems usually focus on a causal flow from sensors to effectors, by which an animal coordinates its actions with exogenous changes in its environment. We propose, instead, that much early sensing was reafferent; it was responsive to the consequences of the animal's own actions. We distinguish two general categories of reafference-translocational and deformational-and use these to survey the distribution of several often-neglected forms of sensing, including gravity sensing, flow sensing and proprioception. We discuss sensing of these kinds in sponges, ctenophores, placozoans, cnidarians and bilaterians. Reafference is ubiquitous, as ongoing action, especially whole-body motility, will almost inevitably influence the senses. Corollary discharge-a pathway or circuit by which an animal tracks its own actions and their reafferent consequences-is not a necessary feature of reafferent sensing but a later-evolving mechanism. We also argue for the importance of reafferent sensing to the evolution of the body-self, a form of organization that enables an animal to sense and act as a single unit. This article is part of the theme issue 'Basal cognition: multicellularity, neurons and the cognitive lens'.
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Affiliation(s)
- Gáspár Jékely
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
| | - Peter Godfrey-Smith
- School of History and Philosophy of Science, University of Sydney, New South Wales 2006, Australia
| | - Fred Keijzer
- Department of Theoretical Philosophy, University of Groningen, Groningen, The Netherlands
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22
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Evidence for sponges as sister to all other animals from partitioned phylogenomics with mixture models and recoding. Nat Commun 2021; 12:1783. [PMID: 33741994 PMCID: PMC7979703 DOI: 10.1038/s41467-021-22074-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 02/24/2021] [Indexed: 11/08/2022] Open
Abstract
Resolving the relationships between the major lineages in the animal tree of life is necessary to understand the origin and evolution of key animal traits. Sponges, characterized by their simple body plan, were traditionally considered the sister group of all other animal lineages, implying a gradual increase in animal complexity from unicellularity to complex multicellularity. However, the availability of genomic data has sparked tremendous controversy as some phylogenomic studies support comb jellies taking this position, requiring secondary loss or independent origins of complex traits. Here we show that incorporating site-heterogeneous mixture models and recoding into partitioned phylogenomics alleviates systematic errors that hamper commonly-applied phylogenetic models. Testing on real datasets, we show a great improvement in model-fit that attenuates branching artefacts induced by systematic error. We reanalyse key datasets and show that partitioned phylogenomics does not support comb jellies as sister to other animals at either the supermatrix or partition-specific level.
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23
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Jékely G, Budd GE. Animal Phylogeny: Resolving the Slugfest of Ctenophores, Sponges and Acoels? Curr Biol 2021; 31:R202-R204. [DOI: 10.1016/j.cub.2020.12.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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24
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Shore AJ, Wood RA, Butler IB, Zhuravlev AY, McMahon S, Curtis A, Bowyer FT. Ediacaran metazoan reveals lophotrochozoan affinity and deepens root of Cambrian Explosion. SCIENCE ADVANCES 2021; 7:7/1/eabf2933. [PMID: 33523867 PMCID: PMC7775780 DOI: 10.1126/sciadv.abf2933] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 11/09/2020] [Indexed: 05/12/2023]
Abstract
Through exceptional preservation, we establish a phylogenetic connection between Ediacaran and Cambrian metazoans. We describe the first three-dimensional, pyritized soft tissue in Namacalathus from the Ediacaran Nama Group, Namibia, which follows the underlying form of a stalked, cup-shaped, calcitic skeleton, with six radially arranged lobes projecting into an apical opening and lateral lumens. A thick body wall and probable J-shaped gut are present within the cup, and the middle layer of the often-spinose skeleton and skeletal pores are selectively pyritized, supporting an organic-rich composition and tripartite construction with possible sensory punctae. These features suggest a total group lophotrochozoan affinity. These morphological data support molecular phylogenies and demonstrates that the origin of modern lophotrochozoan phyla, and their ability to biomineralize, had deep roots in the Ediacaran.
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Affiliation(s)
- A J Shore
- School of GeoSciences, University of Edinburgh, James Hutton Road, Edinburgh EH9 3FE, UK.
| | - R A Wood
- School of GeoSciences, University of Edinburgh, James Hutton Road, Edinburgh EH9 3FE, UK
| | - I B Butler
- School of GeoSciences, University of Edinburgh, James Hutton Road, Edinburgh EH9 3FE, UK
| | - A Yu Zhuravlev
- Department of Biological Evolution, Faculty of Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow 119991, Russia
| | - S McMahon
- School of GeoSciences, University of Edinburgh, James Hutton Road, Edinburgh EH9 3FE, UK
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, James Clerk Maxwell Building, Peter Guthrie Tait Road, Edinburgh EH9 3FD, UK
| | - A Curtis
- School of GeoSciences, University of Edinburgh, James Hutton Road, Edinburgh EH9 3FE, UK
| | - F T Bowyer
- School of GeoSciences, University of Edinburgh, James Hutton Road, Edinburgh EH9 3FE, UK
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25
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Fleming JF, Feuda R, Roberts NW, Pisani D. A Novel Approach to Investigate the Effect of Tree Reconstruction Artifacts in Single-Gene Analysis Clarifies Opsin Evolution in Nonbilaterian Metazoans. Genome Biol Evol 2020; 12:3906-3916. [PMID: 32031627 PMCID: PMC7058159 DOI: 10.1093/gbe/evaa015] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2020] [Indexed: 12/02/2022] Open
Abstract
Our ability to correctly reconstruct a phylogenetic tree is strongly affected by both systematic errors and the amount of phylogenetic signal in the data. Current approaches to tackle tree reconstruction artifacts, such as the use of parameter-rich models, do not translate readily to single-gene alignments. This, coupled with the limited amount of phylogenetic information contained in single-gene alignments, makes gene trees particularly difficult to reconstruct. Opsin phylogeny illustrates this problem clearly. Opsins are G-protein coupled receptors utilized in photoreceptive processes across Metazoa and their protein sequences are roughly 300 amino acids long. A number of incongruent opsin phylogenies have been published and opsin evolution remains poorly understood. Here, we present a novel approach, the canary sequence approach, to investigate and potentially circumvent errors in single-gene phylogenies. First, we demonstrate our approach using two well-understood cases of long-branch attraction in single-gene data sets, and simulations. After that, we apply our approach to a large collection of well-characterized opsins to clarify the relationships of the three main opsin subfamilies.
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Affiliation(s)
- James F Fleming
- School of Earth Sciences, University of Bristol, United Kingdom.,Faculty of Environment and Information Studies, Keio University, Tsuruoka, Yamagata, Japan
| | - Roberto Feuda
- School of Earth Sciences, University of Bristol, United Kingdom
| | | | - Davide Pisani
- School of Earth Sciences, University of Bristol, United Kingdom.,School of Biological Sciences, University of Bristol, United Kingdom
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26
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Marín I. Tumor Necrosis Factor Superfamily: Ancestral Functions and Remodeling in Early Vertebrate Evolution. Genome Biol Evol 2020; 12:2074-2092. [PMID: 33210144 PMCID: PMC7674686 DOI: 10.1093/gbe/evaa140] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/29/2020] [Indexed: 01/01/2023] Open
Abstract
The evolution of the tumor necrosis factor superfamily (TNFSF) in early vertebrates is inferred by comparing the TNFSF genes found in humans and nine fishes: three agnathans, two chondrichthyans, three actinopterygians, and the sarcopterygian Latimeria chalumnae. By combining phylogenetic and synteny analyses, the TNFSF sequences detected are classified into five clusters of genes and 24 orthology groups. A model for their evolution since the origin of vertebrates is proposed. Fifteen TNFSF genes emerged from just three progenitors due to the whole-genome duplications (WGDs) that occurred before the agnathan/gnathostome split. Later, gnathostomes not only kept most of the genes emerged in the WGDs but soon added several tandem duplicates. More recently, complex, lineage-specific patterns of duplications and losses occurred in different gnathostome lineages. In agnathan species only seven to eight TNFSF genes are detected, because this lineage soon lost six of the genes emerged in the ancestral WGDs and additional losses in both hagfishes and lampreys later occurred. The orthologs of many of these lost genes are, in mammals, ligands of death-domain-containing TNFSF receptors, indicating that the extrinsic apoptotic pathway became simplified in the agnathan lineage. From the patterns of emergence of these genes, it is deduced that both the regulation of apoptosis and the control of the NF-κB pathway that depends in modern mammals on TNFSF members emerged before the ancestral vertebrate WGDs.
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Affiliation(s)
- Ignacio Marín
- Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas (IBV-CSIC), Valencia, Spain
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27
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Hancy AD, Antcliffe JB. Anoxia can increase the rate of decay for cnidarian tissue: Using Actinia equina to understand the early fossil record. GEOBIOLOGY 2020; 18:167-184. [PMID: 31990129 DOI: 10.1111/gbi.12370] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 10/02/2019] [Accepted: 11/05/2019] [Indexed: 06/10/2023]
Abstract
An experimental decay methodology is developed for a cnidarian model organism to serve as a comparison to the many previous such studies on bilaterians. This allows an examination of inherent bias against the fossilisation of cnidarian tissue and their diagnostic characters, under what conditions these occur, and in what way. The decay sequence of Actinia equina was examined under a series of controlled conditions. These experiments show that cnidarian decay begins with an initial rupturing of the epidermis, followed by rapid loss of recognisable internal morphological characters. This suggests that bacteria work quicker on the epidermis than autolysis does on the internal anatomy. The data also show that diploblastic tissue is not universally decayed more slowly under anoxic or reducing conditions than under oxic conditions. Indeed, some cnidarian characters decay more rapidly under anoxic conditions than they do under oxic conditions. This suggests the decay pathways acting may be different to those affecting soft bilaterian tissue such as soft epidermis and internal organs. What is most important in the decay of soft polyp anatomy is the microbial community, which can be dominated by oxic or anoxic bacteria. Different Lagerstätte, even of the same type, will inevitably have subtle difference in their bacterial communities, which among other factors, could be a control on soft polyp preservation leading to either an absence of compelling soft anthozoans (Burgess Shale) or an astonishing abundance (Qingjiang biota).
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Affiliation(s)
- Anthony D Hancy
- School of Earth Sciences, University of Bristol, Bristol, UK
| | - Jonathan B Antcliffe
- Oxford University Museum of Natural History, Oxford, UK
- Institut des Sciences de la Terre, Bâtiment Géopolis, UNIL-Mouline, Université de Lausanne, Lausanne, Switzerland
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A Screen for Gene Paralogies Delineating Evolutionary Branching Order of Early Metazoa. G3-GENES GENOMES GENETICS 2020; 10:811-826. [PMID: 31879283 PMCID: PMC7003098 DOI: 10.1534/g3.119.400951] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The evolutionary diversification of animals is one of Earth’s greatest marvels, yet its earliest steps are shrouded in mystery. Animals, the monophyletic clade known as Metazoa, evolved wildly divergent multicellular life strategies featuring ciliated sensory epithelia. In many lineages epithelial sensoria became coupled to increasingly complex nervous systems. Currently, different phylogenetic analyses of single-copy genes support mutually-exclusive possibilities that either Porifera or Ctenophora is sister to all other animals. Resolving this dilemma would advance the ecological and evolutionary understanding of the first animals and the evolution of nervous systems. Here we describe a comparative phylogenetic approach based on gene duplications. We computationally identify and analyze gene families with early metazoan duplications using an approach that mitigates apparent gene loss resulting from the miscalling of paralogs. In the transmembrane channel-like (TMC) family of mechano-transducing channels, we find ancient duplications that define separate clades for Eumetazoa (Placozoa + Cnidaria + Bilateria) vs. Ctenophora, and one duplication that is shared only by Eumetazoa and Porifera. In the Max-like protein X (MLX and MLXIP) family of bHLH-ZIP regulators of metabolism, we find that all major lineages from Eumetazoa and Porifera (sponges) share a duplicated gene pair that is sister to the single-copy gene maintained in Ctenophora. These results suggest a new avenue for deducing deep phylogeny by choosing rather than avoiding ancient gene paralogies.
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Martynov A, Lundin K, Picton B, Fletcher K, Malmberg K, Korshunova T. Multiple paedomorphic lineages of soft-substrate burrowing invertebrates: parallels in the origin of Xenocratena and Xenoturbella. PLoS One 2020; 15:e0227173. [PMID: 31940379 PMCID: PMC6961895 DOI: 10.1371/journal.pone.0227173] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 12/12/2019] [Indexed: 01/21/2023] Open
Abstract
Paedomorphosis is an important evolutionary force. It has previously been suggested that a soft-substrate sediment-dwelling (infaunal) environment facilitates paedomorphic evolution in marine invertebrates. However, until recently this proposal was never rigorously tested with robust phylogeny and broad taxon selection. Here, for the first time, we present a molecular phylogeny for a majority of the 21 families of one of the largest nudibranch subgroups (Aeolidacea) and show that the externally highly simplified vermiform nudibranch family, Pseudovermidae, with clearly defined paedomorphic traits and inhabiting a soft-substrata environment, is a sister group to the complex nudibranch family, Cumanotidae. We also report the rediscovery of one of the most enigmatic nudibranchs-Xenocratena suecica-on the Swedish and Norwegian coasts 70 years after it was first found. Xenocratena was described from the same location and environment in the Swedish Gullmar fjord as one of the most enigmatic vermiform organisms, Xenoturbella bocki, which represents either an original simple bilaterian body plan or secondary simplification of a more complex organisation. Our results show that Xenocratena suecica reveals an onset of parallel paedomorphic evolution so we have proposed the new family, Xenocratenidae fam. n., to accommodate the molecular and morphological disparities we discovered. The paedomorphic origin of another aeolidacean family, Embletoniidae, is also demonstrated for the first time. Thus, by presenting three independent lineages from non-closely related aeolidacean families, Xenocratenidae fam. n., Cumanotidae and Embletoniidae, we confirm with phylogenetic data that a soft-substrata burrowing-related environment strongly favours paedomorphic evolution. We suggest criteria to distinguish ancestral and derived characters in the context of modifications of ontogenetic cycles. Applying an evolutionary model of the soft substrate-driven multiple paedomorphic origin of several families of nudibranch molluscs we propose that it is plausible to extend this model to other marine invertebrates and suggest that the ancestral organisation of the enigmatic metazoan, Xenoturbella, might correspond to the larval part of a complex ancestral bilaterian ontogenetic cycle with sedentary/semi-sedentary adult stages and planula-like larval stages.
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Affiliation(s)
| | - Kennet Lundin
- Gothenburg Natural History Museum, Gothenburg, Sweden
- Gothenburg Global Biodiversity Centre, Gothenburg, Sweden
| | - Bernard Picton
- National Museums Northern Ireland, Holywood, Northern Ireland, United Kingdom
- Queen’s University, Belfast, Northern Ireland, United Kingdom
| | - Karin Fletcher
- Milltech Marine, Port Orchard, Washington, United States of America
| | - Klas Malmberg
- Gothenburg Global Biodiversity Centre, Gothenburg, Sweden
- Gothenburg Global Biodiversity Centre, Aquatilis, Gothenburg, Sweden
| | - Tatiana Korshunova
- Zoological Museum, Moscow State University, Moscow, Russia
- Koltzov Institute of Developmental Biology RAS, Moscow, Russia
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Abstract
Ctenophores or 'comb-jellies' are marine animals whose relationship to other phyla is uncertain, yet important for understanding major steps in animal evolution. Fossil ctenophores from the Cambrian indicate that ctenophores may have evolved from a sessile, cnidarian-like ancestor.
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Affiliation(s)
- Allison C Daley
- Institute of Earth Sciences, University of Lausanne, Geopolis, CH-1015 Lausanne, Switzerland.
| | - Jonathan B Antcliffe
- Institute of Earth Sciences, University of Lausanne, Geopolis, CH-1015 Lausanne, Switzerland
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32
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Mayorova TD, Hammar K, Winters CA, Reese TS, Smith CL. The ventral epithelium of Trichoplax adhaerens deploys in distinct patterns cells that secrete digestive enzymes, mucus or diverse neuropeptides. Biol Open 2019; 8:bio045674. [PMID: 31366453 PMCID: PMC6737977 DOI: 10.1242/bio.045674] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 07/23/2019] [Indexed: 01/11/2023] Open
Abstract
The disk-shaped millimeter-sized marine animal, Trichoplax adhaerens, is notable because of its small number of cell types and primitive mode of feeding. It glides on substrates propelled by beating cilia on its lower surface and periodically pauses to feed on underlying microorganisms, which it digests externally. Here, a combination of advanced electron and light microscopic techniques are used to take a closer look at its secretory cell types and their roles in locomotion and feeding. We identify digestive enzymes in lipophils, a cell type implicated in external digestion and distributed uniformly throughout the ventral epithelium except for a narrow zone near its edge. We find three morphologically distinct types of gland cell. The most prevalent contains and secretes mucus, which is shown to be involved in adhesion and gliding. Half of the mucocytes are arrayed in a tight row around the edge of the ventral epithelium while the rest are scattered further inside, in the region containing lipophils. The secretory granules in mucocytes at the edge label with an antibody against a neuropeptide that was reported to arrest ciliary beating during feeding. A second type of gland cell is arrayed in a narrow row just inside the row of mucocytes while a third is located more centrally. Our maps of the positions of the structurally distinct secretory cell types provide a foundation for further characterization of the multiple peptidergic cell types in Trichoplax and the microscopic techniques we introduce provide tools for carrying out these studies.
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Affiliation(s)
- Tatiana D Mayorova
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 49 Convent Drive, Bethesda, MD 20892, USA
| | - Katherine Hammar
- Central Microscopy Facility, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543, USA
| | - Christine A Winters
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 49 Convent Drive, Bethesda, MD 20892, USA
| | - Thomas S Reese
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 49 Convent Drive, Bethesda, MD 20892, USA
| | - Carolyn L Smith
- Light Imaging Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, USA
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Laumer CE, Fernández R, Lemer S, Combosch D, Kocot KM, Riesgo A, Andrade SCS, Sterrer W, Sørensen MV, Giribet G. Revisiting metazoan phylogeny with genomic sampling of all phyla. Proc Biol Sci 2019; 286:20190831. [PMID: 31288696 PMCID: PMC6650721 DOI: 10.1098/rspb.2019.0831] [Citation(s) in RCA: 123] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 06/17/2019] [Indexed: 11/21/2022] Open
Abstract
Proper biological interpretation of a phylogeny can sometimes hinge on the placement of key taxa-or fail when such key taxa are not sampled. In this light, we here present the first attempt to investigate (though not conclusively resolve) animal relationships using genome-scale data from all phyla. Results from the site-heterogeneous CAT + GTR model recapitulate many established major clades, and strongly confirm some recent discoveries, such as a monophyletic Lophophorata, and a sister group relationship between Gnathifera and Chaetognatha, raising continued questions on the nature of the spiralian ancestor. We also explore matrix construction with an eye towards testing specific relationships; this approach uniquely recovers support for Panarthropoda, and shows that Lophotrochozoa (a subclade of Spiralia) can be constructed in strongly conflicting ways using different taxon- and/or orthologue sets. Dayhoff-6 recoding sacrifices information, but can also reveal surprising outcomes, e.g. full support for a clade of Lophophorata and Entoprocta + Cycliophora, a clade of Placozoa + Cnidaria, and raising support for Ctenophora as sister group to the remaining Metazoa, in a manner dependent on the gene and/or taxon sampling of the matrix in question. Future work should test the hypothesis that the few remaining uncertainties in animal phylogeny might reflect violations of the various stationarity assumptions used in contemporary inference methods.
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Affiliation(s)
- Christopher E. Laumer
- Museum of Comparative Zoology (MCZ) and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
- EMBL-European Bioinformatics Institute (EBI), Wellcome Genome Campus, Hinxton CB10 1SD, UK
| | - Rosa Fernández
- Museum of Comparative Zoology (MCZ) and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
- Bioinformatics & Genomics Unit, Center for Genomic Regulation, Carrer del Dr. Aiguader 88, 08003 Barcelona (Spain)
| | - Sarah Lemer
- Museum of Comparative Zoology (MCZ) and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
- Marine Laboratory, University of Guam, UOG Station, Mangilao, Guam 96923, USA
| | - David Combosch
- Museum of Comparative Zoology (MCZ) and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
- Marine Laboratory, University of Guam, UOG Station, Mangilao, Guam 96923, USA
| | - Kevin M. Kocot
- Department of Biological Sciences and Alabama Museum of Natural History, The University of Alabama, Campus Box 870344, Tuscaoosa, AL 35487, USA
| | - Ana Riesgo
- Department of Life Sciences, Natural History Museum of London, Cromwell Road, London SW7 5BD, UK
| | - Sónia C. S. Andrade
- Departamento de Genética e Biologia Evolutiva, IB, Universidade de São Paulo, 05508090 São Paulo, SP, Brazil
| | - Wolfgang Sterrer
- Bermuda Natural History Museum, PO Box FL 145, Flatts, FLBX, Bermuda
| | - Martin V. Sørensen
- Natural History Museum of Denmark, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Gonzalo Giribet
- Museum of Comparative Zoology (MCZ) and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
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