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Bellworthy J, Scucchia F, Goodbody-Gringley G, Mass T. Genomic, morphological, and physiological insights into coral acclimation along the depth gradient following an in situ reciprocal transplantation of planulae. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 929:172090. [PMID: 38556020 DOI: 10.1016/j.scitotenv.2024.172090] [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: 12/29/2023] [Revised: 03/06/2024] [Accepted: 03/27/2024] [Indexed: 04/02/2024]
Abstract
Mesophotic coral reefs have been proposed as refugia for corals, providing shelter and larval propagules for shallow water reefs that are disproportionately challenged by global climate change and local anthropogenic stressors. For mesophotic reefs to be a viable refuge, firstly, deep origin larvae must survive on shallow reefs and, secondly, the two environments must be physically connected. This study tested the first condition. Planulae of the reef-building coral Stylophora pistillata from 5-8 and 40-44 m depth in the Gulf of Aqaba were tested in a long-term reciprocal transplantation experiment for their ability to settle and acclimate to depth in situ. We assessed survival rates, photochemical, physiological, and morphological characteristics in juveniles grown at either their parental origin or transplantation depth. Differences in gene expression patterns were compared between mesophotic and shallow corals at the adult, juvenile, and planula life stages. We found high mortality rates among all mesophotic-origin planulae, irrespective of translocation depth. Gene expression patterns suggested that deep planulae lacked settlement competency and experienced increased developmental stress upon release. For surviving shallow origin juveniles, symbiont photochemical acclimation to depth occurred within 8 days, with symbiont communities showing changes in photochemical traits without algal symbiont shuffling. However, coral host physiological and morphological acclimation towards the typical deep phenotype was incomplete within 60 days. Gene expression was influenced by both life stage and depth. A set of differentially expressed genes (DEGs) associated with initial stress responses following transplantation, latent stress response, and environmental effects of depth was identified. This study therefore refutes the Deep Reef Refugia Hypothesis, as the potential for mesophotic-origin S. pistillata planulae to recruit to the shallow reef is low. The potential remains for shallow planulae to survive at mesophotic depths.
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Affiliation(s)
- Jessica Bellworthy
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel; Interuniversity Institute of Marine Sciences, Eilat, Israel.
| | - Federica Scucchia
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel; Interuniversity Institute of Marine Sciences, Eilat, Israel
| | | | - Tali Mass
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel; Morris Kahn Marine Research Station, The Leon H. Charney School of Marine Sciences, University of Haifa, Sdot Yam, Israel
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Scucchia F, Wong K, Zaslansky P, Putnam HM, Goodbody-Gringley G, Mass T. Morphological and genetic mechanisms underlying the plasticity of the coral Porites astreoides across depths in Bermuda. J Struct Biol 2023; 215:108036. [PMID: 37832837 DOI: 10.1016/j.jsb.2023.108036] [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: 06/21/2023] [Revised: 10/08/2023] [Accepted: 10/10/2023] [Indexed: 10/15/2023]
Abstract
The widespread decline of shallow-water coral reefs has fueled interest in assessing whether mesophotic reefs can act as refugia replenishing deteriorated shallower reefs through larval exchange. Here we explore the morphological and molecular basis facilitating survival of planulae and adults of the coral Porites astreoides (Lamarck, 1816; Hexacorallia: Poritidae) along the vertical depth gradient in Bermuda. We found differences in micro-skeletal features such as bigger calyxes and coarser surface of the skeletal spines in shallow corals. Yet, tomographic reconstructions reveal an analogous mineral distribution between shallow and mesophotic adults, pointing to similar skeleton growth dynamics. Our study reveals patterns of host genetic connectivity and minimal symbiont depth-zonation across a broader depth range than previously known for this species in Bermuda. Transcriptional variations across life stages showed different regulation of metabolism and stress response functions, unraveling molecular responses to environmental conditions at different depths. Overall, these findings increase our understanding of coral acclimatory capability across broad vertical gradients, ultimately allowing better evaluation of the refugia potential of mesophotic reefs.
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Affiliation(s)
- Federica Scucchia
- Department of Marine Biology, Leon H. Charney School of Marine Sciences University of Haifa, Israel; The Interuniversity Institute of Marine Sciences, Eilat, Israel.
| | - Kevin Wong
- Department of Biological Sciences, University of Rhode Island, Kingston, United States
| | - Paul Zaslansky
- Department for Operative, Preventive and Pediatric Dentistry, Charité-Universitätsmedizin, Berlin, Germany
| | - Hollie M Putnam
- Department of Biological Sciences, University of Rhode Island, Kingston, United States
| | - Gretchen Goodbody-Gringley
- Central Caribbean Marine Institute, Little Cayman, Cayman Islands; Bermuda Institute of Ocean Sciences, St. George's, Bermuda
| | - Tali Mass
- Department of Marine Biology, Leon H. Charney School of Marine Sciences University of Haifa, Israel.
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3
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Abstract
The goal of comparative developmental biology is identifying mechanistic differences in embryonic development between different taxa and how these evolutionary changes have led to morphological and organizational differences in adult body plans. Much of this work has focused on direct-developing species in which the adult forms straight from the embryo and embryonic modifications have direct effects on the adult. However, most animal lineages are defined by indirect development, in which the embryo gives rise to a larval body plan and the adult forms by transformation of the larva. Historically, much of our understanding of complex life cycles is viewed through the lenses of ecology and zoology. In this review, we discuss the importance of establishing developmental rather than morphological or ecological criteria for defining developmental mode and explicitly considering the evolutionary implications of incorporating complex life cycles into broad developmental comparisons of embryos across metazoans.
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Affiliation(s)
- Laurent Formery
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, California, USA;
- Department of Cell and Molecular Biology, University of California, Berkeley, California, USA
| | - Christopher J Lowe
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, California, USA;
- Chan Zuckerberg BioHub, San Francisco, California, USA
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4
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Arenas-Mena C, Akin S. Widespread priming of transcriptional regulatory elements by incipient accessibility or RNA polymerase II pause in early embryos of the sea urchin Strongylocentrotus purpuratus. Genetics 2023; 225:iyad145. [PMID: 37551428 PMCID: PMC10789315 DOI: 10.1093/genetics/iyad145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 05/17/2023] [Accepted: 07/25/2023] [Indexed: 08/09/2023] Open
Abstract
Transcriptional regulatory elements (TREs) are the primary nodes that control developmental gene regulatory networks. In embryo stages, larvae, and adult differentiated red spherule cells of the sea urchin Strongylocentrotus purpuratus, transcriptionally engaged TREs are detected by Precision Run-On Sequencing (PRO-seq), which maps genome-wide at base pair resolution the location of paused or elongating RNA polymerase II (Pol II). In parallel, TRE accessibility is estimated by the Assay for Transposase-Accessible Chromatin using Sequencing (ATAC-seq). Our analysis identifies surprisingly early and widespread TRE accessibility in 4-cell cleavage embryos that is not necessarily followed by concurrent or subsequent transcription. TRE transcriptional differences identified by PRO-seq provide more contrast among embryonic stages than ATAC-seq accessibility differences, in agreement with the apparent excess of accessible but inactive TREs during embryogenesis. Global TRE accessibility reaches a maximum around the 20-hour late blastula stage, which coincides with the consolidation of major embryo regionalizations and peak histone variant H2A.Z expression. A transcriptional potency model based on labile nucleosome TRE occupancy driven by DNA sequences and the prevalence of histone variants is proposed in order to explain the basal accessibility of transcriptionally inactive TREs during embryogenesis. However, our results would not reconcile well with labile nucleosome models based on simple A/T sequence enrichment. In addition, a large number of distal TREs become transcriptionally disengaged during developmental progression, in support of an early Pol II paused model for developmental gene regulation that eventually resolves in transcriptional activation or silencing. Thus, developmental potency in early embryos may be facilitated by incipient accessibility and transcriptional pause at TREs.
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Affiliation(s)
- Cesar Arenas-Mena
- Department of Biology, College of Staten Island, City University of New York (CUNY), 2800 Victory Boulevard, Staten Island, NY, 10314, USA
- PhD Programs in Biology and Biochemistry at the City University of New York (CUNY), Graduate Center, 365 Fifth Avenue, New York, NY, 10016, USA
| | - Serhat Akin
- Department of Biology, College of Staten Island, City University of New York (CUNY), 2800 Victory Boulevard, Staten Island, NY, 10314, USA
- PhD Program in Biology at the City University of New York (CUNY), Graduate Center, 365 Fifth Avenue, New York, NY, 10016, USA
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5
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Baghban N, Khoradmehr A, Afshar A, Jafari N, Zendehboudi T, Rasekh P, Abolfathi LG, Barmak A, Mohebbi G, Akmaral B, Askerovich KA, Maratovich MN, Azari H, Assadi M, Nabipour I, Tamadon A. MRI Tracking of Marine Proliferating Cells In Vivo Using Anti-Oct4 Antibody-Conjugated Iron Nanoparticles for Precision in Regenerative Medicine. BIOSENSORS 2023; 13:268. [PMID: 36832034 PMCID: PMC9953982 DOI: 10.3390/bios13020268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 01/09/2023] [Accepted: 01/11/2023] [Indexed: 06/18/2023]
Abstract
Marine invertebrates are multicellular organisms consisting of a wide range of marine environmental species. Unlike vertebrates, including humans, one of the challenges in identifying and tracking invertebrate stem cells is the lack of a specific marker. Labeling stem cells with magnetic particles provides a non-invasive, in vivo tracking method using MRI. This study suggests antibody-conjugated iron nanoparticles (NPs), which are detectable with MRI for in vivo tracking, to detect stem cell proliferation using the Oct4 receptor as a marker of stem cells. In the first phase, iron NPs were fabricated, and their successful synthesis was confirmed using FTIR spectroscopy. Next, the Alexa Fluor anti-Oct4 antibody was conjugated with as-synthesized NPs. Their affinity to the cell surface marker in fresh and saltwater conditions was confirmed using two types of cells, murine mesenchymal stromal/stem cell culture and sea anemone stem cells. For this purpose, 106 cells of each type were exposed to NP-conjugated antibodies and their affinity to antibodies was confirmed by an epi-fluorescent microscope. The presence of iron-NPs imaged with the light microscope was confirmed by iron staining using Prussian blue stain. Next, anti-Oct4 antibodies conjugated with iron NPs were injected into a brittle star, and proliferating cells were tracked by MRI. To sum up, anti-Oct4 antibodies conjugated with iron NPs not only have the potential for identifying proliferating stem cells in different cell culture conditions of sea anemone and mouse cell cultures but also has the potential to be used for in vivo MRI tracking of marine proliferating cells.
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Affiliation(s)
- Neda Baghban
- The Persian Gulf Marine Biotechnology Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr 7514633196, Iran
| | - Arezoo Khoradmehr
- The Persian Gulf Marine Biotechnology Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr 7514633196, Iran
| | - Alireza Afshar
- The Persian Gulf Marine Biotechnology Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr 7514633196, Iran
- PerciaVista R&D Co., Shiraz 7167683745, Iran
| | - Nazanin Jafari
- The Persian Gulf Marine Biotechnology Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr 7514633196, Iran
| | - Tuba Zendehboudi
- The Persian Gulf Marine Biotechnology Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr 7514633196, Iran
| | - Poorya Rasekh
- The Persian Gulf Marine Biotechnology Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr 7514633196, Iran
| | - Leila Gholamian Abolfathi
- MRI Department, Heart Hospital of Bushehr, Bushehr University of Medical Sciences, Bushehr 7514633196, Iran
| | - Alireza Barmak
- Food Laboratory, Bushehr University of Medical Sciences, Bushehr 7518759577, Iran
| | - Gholamhossein Mohebbi
- The Persian Gulf Marine Biotechnology Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr 7514633196, Iran
| | - Baspakova Akmaral
- Department for Scientific Work, West Kazakhstan Marat Ospanov Medical Unversity, Aktobe 030012, Kazakhstan
| | - Kaliyev Asset Askerovich
- General Surgery, West-Kazakhstan Medical University Named after Marat Ospanov, Aktobe 030012, Kazakhstan
| | - Mussin Nadiar Maratovich
- General Surgery, West-Kazakhstan Medical University Named after Marat Ospanov, Aktobe 030012, Kazakhstan
| | - Hossein Azari
- The Persian Gulf Marine Biotechnology Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr 7514633196, Iran
| | - Majid Assadi
- Nuclear Medicine and Molecular Imaging Research Center, School of Medicine, Bushehr University of Medical Sciences, Bushehr 7514633196, Iran
| | - Iraj Nabipour
- The Persian Gulf Marine Biotechnology Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr 7514633196, Iran
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Okura Y, Kuraishi R, Kaneko H. Size adjustment occurs during the larval growth of the separated blastomeres of the starfish, Patiria Pectinifera. Dev Growth Differ 2022; 64:517-526. [PMID: 36221193 DOI: 10.1111/dgd.12817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 08/12/2022] [Accepted: 08/30/2022] [Indexed: 12/31/2022]
Abstract
Starfish embryos derived from blastomeres separated at the early cleavage stage exhibit morphogenesis to form normally shaped, but smaller-sized dwarf bipinnaria larvae. To further understand this developmental capacity, we primarily characterized the morphogenetic processes of separated 2-cell and 4-cell stage blastomeres during the embryonic and larval periods of the starfish, Patiria Pectinifera. Using non-separated blastomeres as the control, we subjected the separated blastomeres to morphological analyses in conjunction with quantitative measurements of the changes in their body sizes with time post-fertilization. Our results were as follows: (i) Blastomeres separated at 2-cell and 4-cell stages synchronously developed into dwarf-sized bipinnaria larvae. (ii) Upon reaching a body size of 500-700 μm, all the bipinnaria larvae originating from the separated blastomeres and controls began to undergo a series of similar organ formation events in preparation for metamorphosis-recognized as the demarcation between the early and late substages of the bipinnaria larval period. (iii) The separated blastomeres became brachiolaria larvae capable of undergoing metamorphosis at differing rates after reaching approximately 1000-1200 μm body sizes, with adult rudiment and sensory organ forming functionally. (iv) The unfed controls and dwarf bipinnaria larvae derived from blastomeres separated at the 4-cell stage arrested their development synchronously without reaching the threshold size required for the latter half of the bipinnaria stage. These results, taken together, suggested that separated blastomeres possess the developmental capacity to become brachiolaria larvae through a shift in morphogenetic regulation from a synchronous growth to size adjustment during the larval period.
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Affiliation(s)
- Yamato Okura
- The American School in Japan, Chofu-shi, Tokyo, Japan
| | - Ritsu Kuraishi
- Department of Biology, Research, and Education Center for Natural Sciences, Keio University, Yokohama, Kanagawa, Japan
| | - Hiroyuki Kaneko
- Department of Biology, Research, and Education Center for Natural Sciences, Keio University, Yokohama, Kanagawa, Japan
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7
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Comparisons of cell proliferation and cell death from tornaria larva to juvenile worm in the hemichordate Schizocardium californicum. EvoDevo 2022; 13:13. [PMID: 35668535 PMCID: PMC9169294 DOI: 10.1186/s13227-022-00198-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 05/13/2022] [Indexed: 12/06/2022] Open
Abstract
Background There are a wide range of developmental strategies in animal phyla, but most insights into adult body plan formation come from direct-developing species. For indirect-developing species, there are distinct larval and adult body plans that are linked together by metamorphosis. Some outstanding questions in the development of indirect-developing organisms include the extent to which larval tissue undergoes cell death during the process of metamorphosis and when and where the tissue that will give rise to the adult originates. How do the processes of cell division and cell death redesign the body plans of indirect developers? In this study, we present patterns of cell proliferation and cell death during larval body plan development, metamorphosis, and adult body plan formation, in the hemichordate Schizocardium californium (Cameron and Perez in Zootaxa 3569:79–88, 2012) to answer these questions. Results We identified distinct patterns of cell proliferation between larval and adult body plan formation of S. californicum. We found that some adult tissues proliferate during the late larval phase prior to the start of overt metamorphosis. In addition, using an irradiation and transcriptomic approach, we describe a genetic signature of proliferative cells that is shared across the life history states, as well as markers that are unique to larval or juvenile states. Finally, we observed that cell death is minimal in larval stages but begins with the onset of metamorphosis. Conclusions Cell proliferation during the development of S. californicum has distinct patterns in the formation of larval and adult body plans. However, cell death is very limited in larvae and begins during the onset of metamorphosis and into early juvenile development in specific domains. The populations of cells that proliferated and gave rise to the larvae and juveniles have a genetic signature that suggested a heterogeneous pool of proliferative progenitors, rather than a set-aside population of pluripotent cells. Taken together, we propose that the gradual morphological transformation of S. californicum is mirrored at the cellular level and may be more representative of the development strategies that characterize metamorphosis in many metazoan animals. Supplementary Information The online version contains supplementary material available at 10.1186/s13227-022-00198-1.
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8
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Pates G, Maceren-Pates M. Notes on the morphological changes in the oocyte of the polychaete Perinereis wilsoni (Glasby and Hsieh 2006) from spawning to the early larval stage. INVERTEBR REPROD DEV 2022. [DOI: 10.1080/07924259.2021.2025159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Gaudioso Pates
- Department of Fisheries Science, Mindanao State University-Naawan, Naawan, Philippines
- Fishery Research Laboratory, Kyushu University, Fukutsu, Japan
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9
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Abstract
In many animals the head develops early, most of the body axis later. A larva composed mostly of the developing front end therefore can attain mobility and feeding earlier in development. Fossils, functional morphology, and inferred homologies indicate that feeding head larvae existed by the Early Cambrian in members of three major clades of animals: ecdysozoans, lophotrochozoans, and deuterostomes. Some of these early larval feeding mechanisms were also those of juveniles and adults (the lophophore of brachiopod larvae and possibly the ciliary band of the dipleurula of hemichordates and echinoderms); some were derived from structures that previously had other functions (appendages of the nauplius). Trochophores that swim with a preoral band of cilia, the prototroch, originated before divergence of annelids and molluscs, but evidence of larval growth and thus a prototrochal role in feeding is lacking for molluscs until the Ordovician. Feeding larvae that definitely originated much later, as in insects, teleost fish, and amphibians, develop all or nearly all of what will become the adult body axis before they begin feeding. On present evidence, head larvae, including feeding head larvae, evolved multiple times early in the evolution of bilaterian animals and never since.
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Affiliation(s)
- Richard R. Strathmann
- Friday Harbor Laboratories, 620 University Road, Friday Harbor, WA 98250, USA
- Friday Harbor Laboratories, 620 University Road, Friday Harbor, WA 98250, USA
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10
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Wang J, Zhang L, Lian S, Qin Z, Zhu X, Dai X, Huang Z, Ke C, Zhou Z, Wei J, Liu P, Hu N, Zeng Q, Dong B, Dong Y, Kong D, Zhang Z, Liu S, Xia Y, Li Y, Zhao L, Xing Q, Huang X, Hu X, Bao Z, Wang S. Evolutionary transcriptomics of metazoan biphasic life cycle supports a single intercalation origin of metazoan larvae. Nat Ecol Evol 2020; 4:725-736. [PMID: 32203475 DOI: 10.1038/s41559-020-1138-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 02/06/2020] [Indexed: 12/16/2022]
Abstract
The transient larva-bearing biphasic life cycle is the hallmark of many metazoan phyla, but how metazoan larvae originated remains a major enigma in animal evolution. There are two hypotheses for larval origin. The 'larva-first' hypothesis suggests that the first metazoans were similar to extant larvae, with later evolution of the adult-added biphasic life cycle; the 'adult-first' hypothesis suggests that the first metazoans were adult forms, with the biphasic life cycle arising later via larval intercalation. Here, we investigate the evolutionary origin of primary larvae by conducting ontogenetic transcriptome profiling for Mollusca-the largest marine phylum characterized by a trochophore larval stage and highly variable adult forms. We reveal that trochophore larvae exhibit rapid transcriptome evolution with extraordinary incorporation of novel genes (potentially contributing to adult shell evolution), and that cell signalling/communication genes (for example, caveolin and innexin) are probably crucial for larval evolution. Transcriptome age analysis of eight metazoan species reveals the wide presence of young larval transcriptomes in both trochozoans and other major metazoan lineages, therefore arguing against the prevailing larva-first hypothesis. Our findings support an adult-first evolutionary scenario with a single metazoan larval intercalation, and suggest that the first appearance of proto-larva probably occurred after the divergence of direct-developing Ctenophora from a metazoan ancestor.
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Affiliation(s)
- Jing Wang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
| | - Lingling Zhang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
| | - Shanshan Lian
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
| | - Zhenkui Qin
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Xuan Zhu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Xiaoting Dai
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Zekun Huang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Caihuan Ke
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Zunchun Zhou
- Liaoning Key Lab of Marine Fishery Molecular Biology, Liaoning Ocean and Fisheries Science Research Institute, Dalian, China
| | - Jiankai Wei
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Pingping Liu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Naina Hu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Qifan Zeng
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
| | - Bo Dong
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
| | - Ying Dong
- Liaoning Key Lab of Marine Fishery Molecular Biology, Liaoning Ocean and Fisheries Science Research Institute, Dalian, China
| | - Dexu Kong
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Zhifeng Zhang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Sinuo Liu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Yu Xia
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Yangping Li
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Liang Zhao
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Qiang Xing
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Xiaoting Huang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Xiaoli Hu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.,Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
| | - Zhenmin Bao
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.,Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
| | - Shi Wang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China. .,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China. .,The Sars-Fang Centre, Ocean University of China, Qingdao, China.
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11
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Nielsen C. Origin of the trochophora larva. ROYAL SOCIETY OPEN SCIENCE 2018; 5:180042. [PMID: 30109065 PMCID: PMC6083724 DOI: 10.1098/rsos.180042] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 06/21/2018] [Indexed: 06/08/2023]
Abstract
The trochophora larva, which is so well known from the marine plankton, is central to our understanding of the evolution of a large branch of the bilaterians. Two theories for this larval type have been prevalent, the trochaea theory and the theory proposed by Ivanova-Kazas. The embryology, or more precisely the cell-lineage, of these larvae seems to be central for our understanding of their origin, but important details have been missing. According to the trochaea theory, a circumblastoporal ring of blastomeres differentiates to follow the convoluted shape of the conspicuous ciliary bands of the larvae, with prototroch and metatroch around the mouth, forming a filtering system, and telotroch around the anus. According to the Ivanova-Kazas theory, the blastomeres with the ciliary bands develop through specialization of rings of cells of the general ciliation in a lecithotrophic larva. Now, a new cell-lineage study of the gastropod Crepidula has shown that the ring of cells at the edge of the blastopore develops into the band of cells carrying prototroch and metatroch, characteristic of the trochophora. This gives strong support to the trochaea theory.
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12
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Maristem—Stem Cells of Marine/Aquatic Invertebrates: From Basic Research to Innovative Applications. SUSTAINABILITY 2018. [DOI: 10.3390/su10020526] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
Over 100 years of sponge biology research has demonstrated spectacular diversity of cell behaviors during embryonic development, metamorphosis and regeneration. The past two decades have allowed the first glimpses into molecular and cellular mechanisms of these processes. We have learned that while embryonic development of sponges utilizes a conserved set of developmental regulatory genes known from other animals, sponge cell differentiation appears unusually labile. During normal development, and especially as a response to injury, sponge cells appear to have an uncanny ability to transdifferentiate. Here, I argue that sponge cell differentiation plasticity does not preclude homology of cell types and processes between sponges and other animals. Instead, it does provide a wonderful opportunity to better understand transdifferentiation processes in all animals.
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Affiliation(s)
- Maja Adamska
- Division of Biomedical Science and Biochemistry, Research School of Biology, The Australian National University, Canberra, Australia.
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14
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Abstract
The leap from simple unicellularity to complex multicellularity remains one of life's major enigmas. The origins of metazoan developmental gene regulatory mechanisms are sought by analyzing gene regulation in extant eumetazoans, sponges, and unicellular organisms. The main hypothesis of this manuscript is that, developmental enhancers evolved from unicellular inducible promoters that diversified the expression of regulatory genes during metazoan evolution. Promoters and enhancers are functionally similar; both can regulate the transcription of distal promoters and both direct local transcription. Additionally, enhancers have experimentally characterized structural features that reveal their origin from inducible promoters. The distal co-operative regulation among promoters identified in unicellular opisthokonts possibly represents the precursor of distal regulation of promoters by enhancers. During metazoan evolution, constitutive-type promoters of regulatory genes would have acquired novel receptivity to distal regulatory inputs from promoters of inducible genes that eventually specialized as enhancers. The novel regulatory interactions would have caused constitutively expressed genes controlling differential gene expression in unicellular organisms to become themselves differentially expressed. The consequence of the novel regulatory interactions was that regulatory pathways of unicellular organisms became interlaced and ultimately evolved into the intricate developmental gene regulatory networks (GRNs) of extant metazoans.
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Affiliation(s)
- César Arenas-Mena
- Department of Biology, College of Staten Island and Graduate Center, The City University of New York (CUNY), Staten Island, NY 10314, USA
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15
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Gonzalez P, Uhlinger KR, Lowe CJ. The Adult Body Plan of Indirect Developing Hemichordates Develops by Adding a Hox-Patterned Trunk to an Anterior Larval Territory. Curr Biol 2016; 27:87-95. [PMID: 27939313 DOI: 10.1016/j.cub.2016.10.047] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 10/12/2016] [Accepted: 10/25/2016] [Indexed: 01/27/2023]
Abstract
Many animals are indirect developers with distinct larval and adult body plans [1]. The molecular basis of differences between larval and adult forms is often poorly understood, adding a level of uncertainty to comparative developmental studies that use data from both indirect and direct developers. Here we compare the larval and adult body plans of an indirect developing hemichordate, Schizocardium californicum [2]. We describe the expression of 27 transcription factors with conserved roles in deuterostome ectodermal anteroposterior (AP) patterning in developing embryos, tornaria larvae, and post-metamorphic juveniles and show that the tornaria larva of S. californicum is transcriptionally similar to a truncated version of the adult. The larval ectoderm has an anterior molecular signature, while most of the trunk, defined by the expression of hox1-7, is absent. Posterior ectodermal activation of Hox is initiated in the late larva prior to metamorphosis, in preparation for the transition to the adult form, in which the AP axis converges on a molecular architecture similar to that of the direct developing hemichordate Saccoglossus kowalevskii. These results identify a molecular correlate of a major difference in body plan between hemichordate larval and adult forms and confirm the hypothesis that deuterostome larvae are "swimming heads" [3]. This will allow future comparative studies with hemichordates to take into account molecular differences caused by early life history evolution within the phylum. Additionally, comparisons with other phyla suggest that a delay in trunk development is a feature of indirect development shared across distantly related phyla.
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Affiliation(s)
- Paul Gonzalez
- Hopkins Marine Station, Department of Biology, Stanford University, 120 Ocean View Boulevard, Pacific Grove, CA 93950, USA
| | - Kevin R Uhlinger
- Hopkins Marine Station, Department of Biology, Stanford University, 120 Ocean View Boulevard, Pacific Grove, CA 93950, USA
| | - Christopher J Lowe
- Hopkins Marine Station, Department of Biology, Stanford University, 120 Ocean View Boulevard, Pacific Grove, CA 93950, USA.
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16
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Evolutionary origin of endochondral ossification: the transdifferentiation hypothesis. Dev Genes Evol 2016; 227:121-127. [DOI: 10.1007/s00427-016-0567-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 11/23/2016] [Indexed: 02/06/2023]
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17
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High expression of new genes in trochophore enlightening the ontogeny and evolution of trochozoans. Sci Rep 2016; 6:34664. [PMID: 27698463 PMCID: PMC5048140 DOI: 10.1038/srep34664] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 09/19/2016] [Indexed: 11/08/2022] Open
Abstract
Animals with trochophore larvae belong to Trochozoa, one of the main branches of Bilateria. In addition to exhibiting spiral cleavage and early cell fate determination, trochozoans typically undergo indirect development, which contributes to the most unique characteristics of their ontogeny. The indirect development of trochozoans has provoked discussion regarding the origin and evolution of marine larvae and is interesting from the perspective of phylogeny-ontogeny correspondence. While these phylo-onto correlations have an hourglass shape in Deuterostomia, Ecdysozoa, plants and even fungi, they have seldom been studied in Trochozoa, and even Lophotrochozoa. Here, we compared the ontogenetic transcriptomes of the Pacific oyster, Crassostrea gigas (Bivalvia, Mollusca), the Pacific abalone, Haliotis discus hannai (Gastropoda, Mollusca), and the sand worm Perinereis aibuhitensis (Polychaeta, Annelida) using several complementary phylotranscriptomic methods to examine their evolutionary trajectories. The results revealed the late trochophore stage as the phylotypic phase. However, this basic pattern is accompanied with increased use of new genes in the trochophore stages which marks specific adaptations of the larval body plans.
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18
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Randel N, Jékely G. Phototaxis and the origin of visual eyes. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150042. [PMID: 26598725 DOI: 10.1098/rstb.2015.0042] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Vision allows animals to detect spatial differences in environmental light levels. High-resolution image-forming eyes evolved from low-resolution eyes via increases in photoreceptor cell number, improvements in optics and changes in the neural circuits that process spatially resolved photoreceptor input. However, the evolutionary origins of the first low-resolution visual systems have been unclear. We propose that the lowest resolving (two-pixel) visual systems could initially have functioned in visual phototaxis. During visual phototaxis, such elementary visual systems compare light on either side of the body to regulate phototactic turns. Another, even simpler and non-visual strategy is characteristic of helical phototaxis, mediated by sensory-motor eyespots. The recent mapping of the complete neural circuitry (connectome) of an elementary visual system in the larva of the annelid Platynereis dumerilii sheds new light on the possible paths from non-visual to visual phototaxis and to image-forming vision. We outline an evolutionary scenario focusing on the neuronal circuitry to account for these transitions. We also present a comprehensive review of the structure of phototactic eyes in invertebrate larvae and assign them to the non-visual and visual categories. We propose that non-visual systems may have preceded visual phototactic systems in evolution that in turn may have repeatedly served as intermediates during the evolution of image-forming eyes.
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Affiliation(s)
- Nadine Randel
- Max Planck Institute for Developmental Biology, Spemannstrasse 35, 72076 Tübingen, Germany
| | - Gáspár Jékely
- Max Planck Institute for Developmental Biology, Spemannstrasse 35, 72076 Tübingen, Germany
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19
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Wong KSY, Arenas-Mena C. Expression ofGATAandPOUtranscription factors during the development of the planktotrophic trochophore of the polychaete serpulidHydroides elegans. Evol Dev 2016; 18:254-66. [DOI: 10.1111/ede.12196] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Kimberly Suk-Ying Wong
- Department of Biology; San Diego State University; 5500 Campanile Drive San Diego CA 92182-4614 USA
| | - Cesar Arenas-Mena
- Department of Biology, College of Staten Island and Graduate Center; The City University of New York (CUNY); Staten Island NY 10314 USA
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20
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Arenas-Mena C, Coffman JA. Developmental control of transcriptional and proliferative potency during the evolutionary emergence of animals. Dev Dyn 2015; 244:1193-201. [PMID: 26173445 PMCID: PMC4705838 DOI: 10.1002/dvdy.24305] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Revised: 06/18/2015] [Accepted: 07/07/2015] [Indexed: 12/13/2022] Open
Abstract
It is proposed that the evolution of complex animals required repressive genetic mechanisms for controlling the transcriptional and proliferative potency of cells. Unicellular organisms are transcriptionally potent, able to express their full genetic complement as the need arises through their life cycle, whereas differentiated cells of multicellular organisms can only express a fraction of their genomic potential. Likewise, whereas cell proliferation in unicellular organisms is primarily limited by nutrient availability, cell proliferation in multicellular organisms is developmentally regulated. Repressive genetic controls limiting the potency of cells at the end of ontogeny would have stabilized the gene expression states of differentiated cells and prevented disruptive proliferation, allowing the emergence of diverse cell types and functional shapes. We propose that distal cis-regulatory elements represent the primary innovations that set the stage for the evolution of developmental gene regulatory networks and the repressive control of key multipotency and cell-cycle control genes. The testable prediction of this model is that the genomes of extant animals, unlike those of our unicellular relatives, encode gene regulatory circuits dedicated to the developmental control of transcriptional and proliferative potency.
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Affiliation(s)
- Cesar Arenas-Mena
- Department of Biology, College of Staten Island and Graduate Center, The City University of New York (CUNY), Staten Island, New York
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21
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Martín-Durán JM, Vellutini BC, Hejnol A. Evolution and development of the adelphophagic, intracapsular Schmidt's larva of the nemertean Lineus ruber. EvoDevo 2015; 6:28. [PMID: 26417429 PMCID: PMC4584431 DOI: 10.1186/s13227-015-0023-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 09/14/2015] [Indexed: 11/22/2022] Open
Abstract
Background The life cycle of many animals includes a larval stage, which has diversified into an astonishing variety of ecological strategies. The Nemertea is a group of spiralians that exhibits a broad diversity of larval forms, including the iconic pilidium. A pelagic planktotrophic pilidium is the ancestral form in the Pilidiophora, but several lineages exhibit deviations of this condition, mostly as a transition to pelagic lecithotrophy. The most extreme case occurs, however, in the Pilidiophoran Lineus ruber, which exhibits an adelphophagic intracapsular pilidium, the so-called Schmidt’s larva. Results We combined confocal laser scanning microscopy and gene expression studies to characterize the development and metamorphosis of the Schmidt’s larva of L. ruber. The larva forms after gastrulation, and comprises a thin epidermis, a proboscis rudiment and two pairs of imaginal discs from which the juvenile will develop. The cells internalized during gastrulation form a blind gut and the blastopore gives rise to the mouth of the larva and juvenile. The Schmidt’s larva eats other siblings that occupy the same egg capsule, accumulating nutrients for the juvenile. A gradual metamorphosis involves the differentiation of the juvenile cell types from the imaginal discs and the shedding of the larval epidermis. The expression of evolutionarily conserved anterior (foxQ2, six3/6, gsc, otx), endomesodermal (foxA, GATA456-a, twi-a) and posterior (evx, cdx) markers demonstrate that the juvenile retains the molecular patterning of the Schmidt’s larva. After metamorphosis, the juveniles stay over 20 days within the egg masses, until they are fully mature and hatch. Conclusions The evolution of the intracapsular Schmidt’s larva involved the loss of the typical feeding structures of the planktotrophic pilidium and a precocious formation of the imaginal discs, as also observed in other pelagic lecithotrophic forms. However, no special adaptations are observed related to adelphophagy. As in planktotrophic pilidium, the molecular mechanism patterning the juvenile is only active in the imaginal discs and not during the early development of the larva, suggesting two separate molecular programs during nemertean embryogenesis. Our results illuminate the diversification of larval forms in the Pilidiophora and Nemertea, and thus on the developmental mechanisms underlying metazoan larval evolution. Electronic supplementary material The online version of this article (doi:10.1186/s13227-015-0023-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- José M Martín-Durán
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5008 Bergen, Norway
| | - Bruno C Vellutini
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5008 Bergen, Norway
| | - Andreas Hejnol
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5008 Bergen, Norway
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22
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Lyons DC, Perry KJ, Henry JQ. Spiralian gastrulation: germ layer formation, morphogenesis, and fate of the blastopore in the slipper snail Crepidula fornicata. EvoDevo 2015; 6:24. [PMID: 26664718 PMCID: PMC4673862 DOI: 10.1186/s13227-015-0019-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 04/15/2015] [Indexed: 12/14/2022] Open
Abstract
Background Gastrulation is a critical step in bilaterian development, directly linked to the segregation of germ layers, establishment of axes, and emergence of the through-gut. Theories about the evolution of gastrulation often concern the fate of the blastopore (site of endomesoderm internalization), which varies widely in a major branch of bilaterians, the Spiralia. In this group, the blastopore has been said to become the mouth, the anus, both, or neither. Different developmental explanations for this variation exist, yet no modern lineage tracing study has ever correlated the position of cells surrounding the blastopore with their contribution to tissues of the mouth, foregut, and anus in a spiralian. This is the first study to do so, using the gastropod Crepidula fornicata. Results Crepidula gastrulation occurs by epiboly: the first through third quartet micromeres form an epithelial animal cap that expands to cover vegetal endomesodermal precursors. Initially, descendants of the second and third quartet micromeres (2a–2d, 3a–3d) occupy a portion of the blastopore lip. As the blastopore narrows, the micromeres’ progeny exhibit lineage-specific behaviors that result in certain sublineages leaving the lip’s edge. Anteriorly, cells derived from 3a2 and 3b2 undergo a unique epithelial-to-mesenchymal transition involving proliferation and a collective movement of cells into the archenteron. These cells make a novel spiralian germ layer, the ectomesoderm. Posteriorly, cells derived from 3c2 and 3d2 undergo a form of convergence and extension that involves zippering of cells and their intercalation across the ventral midline. During this process, several of these cells, as well as the 2d clone, become displaced posteriorly, away from the blastopore. Progeny of 2a-2c and 3a-3d make the mouth and foregut, and the blastopore becomes the opening to the mouth. The anus forms days later, as a secondary opening within the 2d2 clone, and not from the classically described “anal cells”, which we identify as the 3c221 and 3d221 cells. Conclusions Our analysis of Crepidula gastrulation constitutes the first description of blastopore lip morphogenesis and fates using lineage tracing and live imaging. These data have profound implications for hypotheses about the evolution of the bilaterian gut and help explain observed variation in blastopore morphogenesis among spiralians. Electronic supplementary material The online version of this article (doi:10.1186/s13227-015-0019-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Deirdre C Lyons
- Biology Department, Duke University, 124 Science Drive, Durham, NC 27708 USA
| | - Kimberly J Perry
- Department of Cell and Developmental Biology, University of Illinois, 601 S. Goodwin Ave., Urbana, IL 61801 USA
| | - Jonathan Q Henry
- Department of Cell and Developmental Biology, University of Illinois, 601 S. Goodwin Ave., Urbana, IL 61801 USA
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23
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Nielsen C. Life cycle evolution: was the eumetazoan ancestor a holopelagic, planktotrophic gastraea? BMC Evol Biol 2013; 13:171. [PMID: 23957497 PMCID: PMC3751718 DOI: 10.1186/1471-2148-13-171] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 08/06/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Two theories for the origin of animal life cycles with planktotrophic larvae are now discussed seriously: The terminal addition theory proposes a holopelagic, planktotrophic gastraea as the ancestor of the eumetazoans with addition of benthic adult stages and retention of the planktotrophic stages as larvae, i.e. the ancestral life cycles were indirect. The intercalation theory now proposes a benthic, deposit-feeding gastraea as the bilaterian ancestor with a direct development, and with planktotrophic larvae evolving independently in numerous lineages through specializations of juveniles. RESULTS Information from the fossil record, from mapping of developmental types onto known phylogenies, from occurrence of apical organs, and from genetics gives no direct information about the ancestral eumetazoan life cycle; however, there are plenty of examples of evolution from an indirect development to direct development, and no unequivocal example of evolution in the opposite direction. Analyses of scenarios for the two types of evolution are highly informative. The evolution of the indirect spiralian life cycle with a trochophora larva from a planktotrophic gastraea is explained by the trochophora theory as a continuous series of ancestors, where each evolutionary step had an adaptational advantage. The loss of ciliated larvae in the ecdysozoans is associated with the loss of outer ciliated epithelia. A scenario for the intercalation theory shows the origin of the planktotrophic larvae of the spiralians through a series of specializations of the general ciliation of the juvenile. The early steps associated with the enhancement of swimming seem probable, but the following steps which should lead to the complicated downstream-collecting ciliary system are without any advantage, or even seem disadvantageous, until the whole structure is functional. None of the theories account for the origin of the ancestral deuterostome (ambulacrarian) life cycle. CONCLUSIONS All the available information is strongly in favor of multiple evolution of non-planktotrophic development, and only the terminal addition theory is in accordance with the Darwinian theory by explaining the evolution through continuous series of adaptational changes. This implies that the ancestor of the eumetazoans was a holopelagic, planktotrophic gastraea, and that the adult stages of cnidarians (sessile) and bilaterians (creeping) were later additions to the life cycle. It further implies that the various larval types are of considerable phylogenetic value.
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Affiliation(s)
- Claus Nielsen
- Zoological Museum, The Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark.
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Materna SC, Swartz SZ, Smith J. Notch and Nodal control forkhead factor expression in the specification of multipotent progenitors in sea urchin. Development 2013; 140:1796-806. [PMID: 23533178 PMCID: PMC3621494 DOI: 10.1242/dev.091157] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/18/2013] [Indexed: 01/23/2023]
Abstract
Indirect development, in which embryogenesis gives rise to a larval form, requires that some cells retain developmental potency until they contribute to the different tissues in the adult, including the germ line, in a later, post-embryonic phase. In sea urchins, the coelomic pouches are the major contributor to the adult, but how coelomic pouch cells (CPCs) are specified during embryogenesis is unknown. Here we identify the key signaling inputs into the CPC specification network and show that the forkhead factor foxY is the first transcription factor specifically expressed in CPC progenitors. Through dissection of its cis-regulatory apparatus we determine that the foxY expression pattern is the result of two signaling inputs: first, Delta/Notch signaling activates foxY in CPC progenitors; second, Nodal signaling restricts its expression to the left side, where the adult rudiment will form, through direct repression by the Nodal target pitx2. A third signal, Hedgehog, is required for coelomic pouch morphogenesis and institution of laterality, but does not directly affect foxY transcription. Knockdown of foxY results in a failure to form coelomic pouches and disrupts the expression of virtually all transcription factors known to be expressed in this cell type. Our experiments place foxY at the top of the regulatory hierarchy underlying the specification of a cell type that maintains developmental potency.
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Affiliation(s)
- Stefan C. Materna
- California Institute of Technology, Division of Biology, m/c 156-29, Pasadena, CA 91125, USA
| | - S. Zachary Swartz
- Brown University, Department of Molecular Biology, Cell Biology and Biochemistry, 185 Meeting Street, Providence, RI 02912, USA
| | - Joel Smith
- California Institute of Technology, Division of Biology, m/c 156-29, Pasadena, CA 91125, USA
- Brown University, Department of Molecular Biology, Cell Biology and Biochemistry, 185 Meeting Street, Providence, RI 02912, USA
- Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543, USA
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Richards GS, Degnan BM. The expression of Delta ligands in the sponge Amphimedon queenslandica suggests an ancient role for Notch signaling in metazoan development. EvoDevo 2012; 3:15. [PMID: 22824137 PMCID: PMC3482393 DOI: 10.1186/2041-9139-3-15] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Accepted: 06/27/2012] [Indexed: 01/09/2023] Open
Abstract
Background Intercellular signaling via the Notch pathway regulates cell fate, patterning, differentiation and proliferation, and is essential for the proper development of bilaterians and cnidarians. To investigate the origins of the Notch pathway, we are studying its deployment in a representative of an early branching lineage, the poriferan Amphimedon queenslandica. The A. queenslandica genome encodes a single Notch receptor and five membrane-bound Delta ligands, as well as orthologs of many genes that enact and regulate canonical Notch signaling events in other animals. Methods In the present report we analyze the structure of the five A. queenslandica Deltas using bioinformatic methods, and characterize their developmental expression via whole mount in situ hybridization and histological staining. Results Sequence analysis of the A. queenslandica Delta ligands highlights the conservation of their extracellular domains. This contrasts with the divergence of their intracellular regions, each of which is predicted to bear a unique repertoire of protein interaction motifs. In keeping with this diversity, these ligands are expressed differentially and dynamically throughout A. queenslandica embryogenesis, both in cell type specific patterns and broader regional domains. Notably, this expression coincides with the development of the photosensitive larval pigment ring, the non-ciliated cuboidal cells located at the anterior pole of the larva, and the intraepithelial flask cells and globular cells that are presumed to have sensory and/or secretory roles. Conclusions Based on the dynamic and complex patterns of expression of these Delta ligands and the Notch receptor, we propose that the Notch signaling pathway is involved in regulating the development of diverse cell types in A. queenslandica. From these observations we infer that Notch signaling is a conserved feature of metazoan development, ancestrally contributing to cell determination, patterning and differentiation processes.
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Affiliation(s)
- Gemma S Richards
- School of Biological Sciences, University of Queensland, Brisbane, QLD, 4072, Australia.
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26
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Bakalenko NI, Novikova EL, Kulakova MA. Regulatory evolution, Hox genes, and larvae of bilateral animals. BIOL BULL+ 2012. [DOI: 10.1134/s1062359012020033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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27
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Rieger V, Perez Y, Müller CHG, Lacalli T, Hansson BS, Harzsch S. Development of the nervous system in hatchlings of Spadella cephaloptera (Chaetognatha), and implications for nervous system evolution in Bilateria. Dev Growth Differ 2011; 53:740-59. [PMID: 21671921 DOI: 10.1111/j.1440-169x.2011.01283.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Chaetognaths (arrow worms) play an important role as predators in planktonic food webs. Their phylogenetic position is unresolved, and among the numerous hypotheses, affinities to both protostomes and deuterostomes have been suggested. Many aspects of their life history, including ontogenesis, are poorly understood and, though some aspects of their embryonic and postembryonic development have been described, knowledge of early neural development is still limited. This study sets out to provide new insights into neurogenesis of newly hatched Spadella cephaloptera and their development during the following days, with attention to the two main nervous centers, the brain and the ventral nerve center. These were examined with immunohistological methods and confocal laser-scan microscopic analysis, using antibodies against tubulin, FMRFamide, and synapsin to trace the emergence of neuropils and the establishment of specific peptidergic subsystems. At hatching, the neuronal architecture of the ventral nerve center is already well established, whereas the brain and the associated vestibular ganglia are still rudimentary. The development of the brain proceeds rapidly over the next 6 days to a state that resembles the adult pattern. These data are discussed in relation to the larval life style and behaviors such as feeding. In addition, we compare the larval chaetognath nervous system and that of other bilaterian taxa in order to extract information with phylogenetic value. We conclude that larval neurogenesis in chaetognaths does not suggest an especially close relationship to either deuterostomes or protostomes, but instead displays many apomorphic features.
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Affiliation(s)
- Verena Rieger
- Zoologisches Institut und Museum, Cytologie und Evolutionsbiologie, Ernst Moritz Arndt Universität Greifswald, Soldmannstraße 23, 17487 Greifswald.
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Ikuta T. Evolution of invertebrate deuterostomes and Hox/ParaHox genes. GENOMICS, PROTEOMICS & BIOINFORMATICS 2011; 9:77-96. [PMID: 21802045 PMCID: PMC5054439 DOI: 10.1016/s1672-0229(11)60011-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Accepted: 03/21/2011] [Indexed: 11/10/2022]
Abstract
Transcription factors encoded by Antennapedia-class homeobox genes play crucial roles in controlling development of animals, and are often found clustered in animal genomes. The Hox and ParaHox gene clusters have been regarded as evolutionary sisters and evolved from a putative common ancestral gene complex, the ProtoHox cluster, prior to the divergence of the Cnidaria and Bilateria (bilaterally symmetrical animals). The Deuterostomia is a monophyletic group of animals that belongs to the Bilateria, and a sister group to the Protostomia. The deuterostomes include the vertebrates (to which we belong), invertebrate chordates, hemichordates, echinoderms and possibly xenoturbellids, as well as acoelomorphs. The studies of Hox and ParaHox genes provide insights into the origin and subsequent evolution of the bilaterian animals. Recently, it becomes apparent that among the Hox and ParaHox genes, there are significant variations in organization on the chromosome, expression pattern, and function. In this review, focusing on invertebrate deuterostomes, I first summarize recent findings about Hox and ParaHox genes. Next, citing unsolved issues, I try to provide clues that might allow us to reconstruct the common ancestor of deuterostomes, as well as understand the roles of Hox and ParaHox genes in the development and evolution of deuterostomes.
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Affiliation(s)
- Tetsuro Ikuta
- Marine Genomics Unit, Okinawa Institute of Science and Technology, Uruma, Japan.
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Martín-Durán JM, Romero R. Evolutionary implications of morphogenesis and molecular patterning of the blind gut in the planarian Schmidtea polychroa. Dev Biol 2011; 352:164-76. [DOI: 10.1016/j.ydbio.2011.01.032] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 01/20/2011] [Accepted: 01/25/2011] [Indexed: 10/18/2022]
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Fusco G, Minelli A. Phenotypic plasticity in development and evolution: facts and concepts. Introduction. Philos Trans R Soc Lond B Biol Sci 2010; 365:547-56. [PMID: 20083631 PMCID: PMC2817147 DOI: 10.1098/rstb.2009.0267] [Citation(s) in RCA: 242] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
This theme issue pursues an exploration of the potential of taking into account the environmental sensitivity of development to explaining the evolution of metazoan life cycles, with special focus on complex life cycles and the role of developmental plasticity. The evolution of switches between alternative phenotypes as a response to different environmental cues and the evolution of the control of the temporal expression of alternative phenotypes within an organism's life cycle are here treated together as different dimensions of the complex relationships between genotype and phenotype, fostering the emergence of a more general and comprehensive picture of phenotypic evolution through a quite diverse sample of case studies. This introductory article reviews fundamental facts and concepts about phenotypic plasticity, adopting the most authoritative terminology in use in the current literature. The main topics are types and components of phenotypic variation, the evolution of organismal traits through plasticity, the origin and evolution of phenotypic plasticity and its adaptive value.
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Affiliation(s)
- Giuseppe Fusco
- Department of Biology, University of Padova, Via U. Bassi 58/B, I-35131 Padova, Italy.
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