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Formery L, Peluso P, Rank DR, Rokhsar DS, Lowe CJ. Antero-posterior patterning in the brittle star Amphipholis squamata and the evolution of echinoderm body plans. EvoDevo 2025; 16:7. [PMID: 40450286 DOI: 10.1186/s13227-025-00244-8] [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: 02/22/2025] [Accepted: 05/11/2025] [Indexed: 06/03/2025] Open
Abstract
Although the adult pentaradial body plan of echinoderms evolved from a bilateral ancestor, identifying axial homologies between the morphologically divergent echinoderms and their bilaterian relatives has been an enduring problem in zoology. The expression of conserved bilaterian patterning genes in echinoderms provides a molecular framework for resolving this puzzle. Recent studies in juvenile asteroids suggest that the bilaterian antero-posterior axis maps onto the medio-lateral axis of the arms, perpendicular to the proximo-distal axis of each of the five rays of the pentaradial body plan. Here, we test this hypothesis in another echinoderm class, the ophiuroids, using the cosmopolitan brittle star Amphipholis squamata. Our results show that the general principles of axial patterning are similar to those described in asteroids, and comparisons with existing molecular data from other echinoderm taxa support the idea that medio-lateral deployment of the bilaterian AP patterning program across the rays predates the evolution of the asterozoans, and likely the echinoderm crown-group. Our data also reveal expression differences between A. squamata and asteroids, which we attribute to secondary modifications specific to ophiuroids. Together, this work provides important comparative data to reconstruct the evolution of axial properties in echinoderm body plans.
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Affiliation(s)
- L Formery
- Department of Biology, Hopkins Marine Station, Stanford University, 120 Oceanview Blvd, Pacific Grove, CA, 93950, USA.
- Department of Cell and Molecular Biology, University of California Berkeley, Berkeley, CA, USA.
| | - P Peluso
- Pacific Biosciences, Menlo Park, CA, USA
| | - D R Rank
- Pacific Biosciences, Menlo Park, CA, USA
| | - D S Rokhsar
- Department of Cell and Molecular Biology, University of California Berkeley, Berkeley, CA, USA
- Molecular Genetics Unit, Okinawa Institute of Science and Technology, Onna, Okinawa, Japan
- Chan Zuckerberg BioHub, San Francisco, CA, USA
| | - C J Lowe
- Department of Biology, Hopkins Marine Station, Stanford University, 120 Oceanview Blvd, Pacific Grove, CA, 93950, USA.
- Chan Zuckerberg BioHub, San Francisco, CA, USA.
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2
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Escárcega-González CE, Hernández-Cuellar E, Ruiz Esparza-Juárez FD, Chávez-Reyes J. Molecular mechanisms associated with embryotoxic effects of heavy metals in the Sea Urchin. Reprod Toxicol 2025; 134:108898. [PMID: 40118295 DOI: 10.1016/j.reprotox.2025.108898] [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: 10/25/2024] [Revised: 02/24/2025] [Accepted: 03/15/2025] [Indexed: 03/23/2025]
Abstract
The sea urchin embryo model has become a classic model for studying the harmful effects of heavy metals and the molecular responses associated with exposure to these pollutants. In this context, several biochemical pathways have been associated with exposure to heavy metals in sea urchin embryos, such as autophagy, apoptosis, oxidative stress, activation of heat shock proteins, and induction of metallothioneins. These biochemical pathways are activated or altered in embryos after exposure to heavy metals; therefore, this review provides a comprehensive literature exploration, summarizing the main biochemical changes observed in sea urchin embryos following exposure to certain heavy metals, such as cadmium, gadolinium, arsenic, manganese, zinc, mercury, copper, nickel, and lead.
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Affiliation(s)
- Carlos E Escárcega-González
- Facultad de Ciencias Químicas Universidad Autónoma de Nuevo León Av., Universidad s/n, CD, Universitaria, San Nicolás de los Garza, NL 66455, Mexico
| | - Eduardo Hernández-Cuellar
- Laboratorio de Biología Celular y Tisular, Departamento de Morfología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Ciudad Universitaria 940, Aguascalientes 20100, Mexico
| | - Fabián D Ruiz Esparza-Juárez
- Departamento de Medicina, Centro de Ciencias de la Salud, Universidad Autónoma de Aguascalientes, Ciudad Universitaria 940, Aguascalientes 20100, Mexico
| | - Jesús Chávez-Reyes
- Departamento de Fisiología y Farmacología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Ciudad Universitaria 940, Aguascalientes 20100, Mexico.
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3
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Miroglio R, Nugnes R, Zanetti L, Faimali M, Gambardella C. Environmental concentrations of fluoxetine antidepressant affect early development of sea urchin Paracentrotus lividus. MARINE ENVIRONMENTAL RESEARCH 2025; 207:107080. [PMID: 40090285 DOI: 10.1016/j.marenvres.2025.107080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2025] [Revised: 02/28/2025] [Accepted: 03/09/2025] [Indexed: 03/18/2025]
Abstract
Fluoxetine (FLX), one of the most widely prescribed selective serotonin reuptake inhibitors, is frequently detected in the aquatic environment. In this study we assessed the ecotoxicological effects of FLX on the early life-stages of the sea urchin Paracentrotus lividus, a key species in the Mediterranean Sea. Fertilization rate, developmental anomalies and behavioural alterations were evaluated up to 72 h by exposing gametes, zygotes, and embryos (gastrula) to environmental (0.001, 0.01 mg/L) and high concentrations (0.1, 1, 10 mg/L). Further, the different types and frequency of morphological anomalies at larval level were classified to estimate the Index of Contaminant Impact (ICI) at relevant and high concentrations. The ICI was applied to predict which FLX concentrations may pose a risk to sea urchins. Although FLX did not affect fertilization, significant skeletal anomalies and behavioural alterations were found in plutei from each exposed stage. Based on EC50 values, the sensitivity level ranks as follows: zygote > gastrula > sperm. The ICI values indicated high and moderate impacts only at high concentrations. However, a slight impact was also found in plutei from zygote exposure at relevant environmental concentrations, highlighting a potential risk for sea urchin early development. Considering increasing FLX consumption, we suggest to include this PC in monitoring plans, to not exceed levels that may impair and severely affect the early developmental stages of echinoderms. In addition, our findings promote the use of ICI as a novel tool for FLX impact assessment.
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Affiliation(s)
- Roberta Miroglio
- National Research Council, Institute of the Anthropic Impact and Sustainability in the marine environment (CNR-IAS), via de Marini 16, 16149, Genova, Italy.
| | - Roberta Nugnes
- National Research Council, Institute of the Anthropic Impact and Sustainability in the marine environment (CNR-IAS), via de Marini 16, 16149, Genova, Italy
| | - Lisa Zanetti
- National Research Council, Institute of the Anthropic Impact and Sustainability in the marine environment (CNR-IAS), via de Marini 16, 16149, Genova, Italy
| | - Marco Faimali
- National Research Council, Institute of the Anthropic Impact and Sustainability in the marine environment (CNR-IAS), via de Marini 16, 16149, Genova, Italy
| | - Chiara Gambardella
- National Research Council, Institute of the Anthropic Impact and Sustainability in the marine environment (CNR-IAS), via de Marini 16, 16149, Genova, Italy
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4
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Asnicar D, Cappelli C, Zanovello L, Masiero L, Badocco D, Marin MG, Munari M. Adaptive resilience of sea urchins against seawater acidification: A study on egg quality and offspring performance within a volcanic vents area. ENVIRONMENTAL RESEARCH 2025; 272:121143. [PMID: 39971114 DOI: 10.1016/j.envres.2025.121143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2025] [Revised: 02/04/2025] [Accepted: 02/14/2025] [Indexed: 02/21/2025]
Abstract
Local adaptation plays a critical role in an organism's ability to survive and reproduce in diverse environmental conditions, potentially improving an organism's response to stressful conditions such as ocean acidification or pollution. In this study, the effects of lower pH coupled with the presence of environmental contaminants were assessed on sea urchins (Paracentrotus lividus) collected outside and inside a volcanic CO2-vent system, where the mean ambient pH is 8.1 and 7.7, respectively. Both groups of sea urchins were spawned, and offspring were reared at pH 8.1 and 7.7, and in the presence or absence of a mixture of 100 μg/L of glyphosate and its main metabolite aminomethylphosphonic acid. Offspring performance metrics (development, abnormalities, and growth) were investigated under the different exposure conditions. The exposure to reduced pH affected the development and larval growth in echinoplutei obtained from adults of both sites, although to a different extent. Chemicals mixture had an additive effect in slowing embryo development. Results revealed that sea urchins living within the lower pH Vents area exhibited significantly higher egg quality, which likely enhanced embryonic development, reduced abnormalities, and increased larval size compared to their counterparts outside the Vents system, both in the presence and absence of contaminants. Findings suggest that sea urchins living within the CO2-Vents system developed adaptations to thrive under lower pH conditions. Elevated egg quality and improved offspring performance suggest organisms' resilience to environmental stressors associated with seawater acidification. Although insights gained from this study are preliminary, mostly due to the limited number of replicates in the egg biochemical analysis, they contribute to unveiling the adaptive capabilities of sea urchins in facing ongoing ocean acidification challenges.
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Affiliation(s)
- Davide Asnicar
- Aquatic Bioscience, Huntsman Marine Science Centre, St Andrews, New Brunswick, Canada; Department of Biology, University of Padova, Padova, Italy.
| | - Costanza Cappelli
- Department of Biology, University of Padova, Padova, Italy; Section for Oceans and Arctic, National Institute of Aquatic Resources (DTU Aqua), Kongens Lyngby, Denmark
| | | | | | - Denis Badocco
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | | | - Marco Munari
- Department of Biology, Stazione Idrobiologica Umberto D'Ancona, University of Padova, Venice, Italy; Department of Integrative Marine Ecology, Ischia Marine Centre, Stazione Zoologica Anton Dohrn, Naples, Italy
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5
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Lebedeva T, Boström J, Kremnyov S, Mörsdorf D, Niedermoser I, Genikhovich E, Hejnol A, Adameyko I, Genikhovich G. β-catenin-driven endomesoderm specification is a Bilateria-specific novelty. Nat Commun 2025; 16:2476. [PMID: 40075083 PMCID: PMC11903683 DOI: 10.1038/s41467-025-57109-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 02/08/2025] [Indexed: 03/14/2025] Open
Abstract
Endomesoderm specification by a maternal β-catenin signal and body axis patterning by interpreting a gradient of zygotic Wnt/β-catenin signalling was suggested to predate the split between Bilateria and their sister clade Cnidaria. However, in Cnidaria, the roles of β-catenin signalling in these processes have not been demonstrated directly. Here, by tagging the endogenous β-catenin in the cnidarian Nematostella vectensis, we confirm that its oral-aboral axis is indeed patterned by a gradient of β-catenin signalling. Strikingly, we show that, in contrast to bilaterians, Nematostella endomesoderm specification is repressed by β-catenin and takes place in the maternal nuclear β-catenin-negative part of the embryo. This completely changes the accepted paradigm and suggests that β-catenin-dependent endomesoderm specification was a bilaterian innovation linking endomesoderm specification to the subsequent posterior-anterior patterning.
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Affiliation(s)
- Tatiana Lebedeva
- Department of Neurosciences and Developmental Biology, Faculty of Life Sciences, University of Vienna, Vienna, Austria
- Vienna Doctoral School of Ecology and Evolution, University of Vienna, Vienna, Austria
- Institute for Zoology and Evolutionary Research, Friedrich Schiller University Jena, Jena, Germany
| | - Johan Boström
- Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Stanislav Kremnyov
- Institute for Zoology and Evolutionary Research, Friedrich Schiller University Jena, Jena, Germany
| | - David Mörsdorf
- Department of Neurosciences and Developmental Biology, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Isabell Niedermoser
- Department of Neurosciences and Developmental Biology, Faculty of Life Sciences, University of Vienna, Vienna, Austria
- Vienna Doctoral School of Ecology and Evolution, University of Vienna, Vienna, Austria
| | | | - Andreas Hejnol
- Institute for Zoology and Evolutionary Research, Friedrich Schiller University Jena, Jena, Germany
| | - Igor Adameyko
- Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Grigory Genikhovich
- Department of Neurosciences and Developmental Biology, Faculty of Life Sciences, University of Vienna, Vienna, Austria.
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6
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Massri AJ, Berrio A, Afanassiev A, Greenstreet L, Pipho K, Byrne M, Schiebinger G, McClay DR, Wray GA. Single-Cell Transcriptomics Reveals Evolutionary Reconfiguration of Embryonic Cell Fate Specification in the Sea Urchin Heliocidaris erythrogramma. Genome Biol Evol 2025; 17:evae258. [PMID: 39587400 PMCID: PMC11719709 DOI: 10.1093/gbe/evae258] [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: 05/13/2024] [Revised: 11/15/2024] [Accepted: 11/19/2024] [Indexed: 11/27/2024] Open
Abstract
Altered regulatory interactions during development likely underlie a large fraction of phenotypic diversity within and between species, yet identifying specific evolutionary changes remains challenging. Analysis of single-cell developmental transcriptomes from multiple species provides a powerful framework for unbiased identification of evolutionary changes in developmental mechanisms. Here, we leverage a "natural experiment" in developmental evolution in sea urchins, where a major life history switch recently evolved in the lineage leading to Heliocidaris erythrogramma, precipitating extensive changes in early development. Comparative analyses of single-cell transcriptome analysis (scRNA-seq) developmental time courses from H. erythrogramma and Lytechinus variegatus (representing the derived and ancestral states, respectively) reveal numerous evolutionary changes in embryonic patterning. The earliest cell fate specification events and the primary signaling center are co-localized in the ancestral developmental gene regulatory network; remarkably, in H. erythrogramma, they are spatially and temporally separate. Fate specification and differentiation are delayed in most embryonic cell lineages, although in some cases, these processes are conserved or even accelerated. Comparative analysis of regulator-target gene co-expression is consistent with many specific interactions being preserved but delayed in H. erythrogramma, while some otherwise widely conserved interactions have likely been lost. Finally, specific patterning events are directly correlated with evolutionary changes in larval morphology, suggesting that they are directly tied to the life history shift. Together, these findings demonstrate that comparative scRNA-seq developmental time courses can reveal a diverse set of evolutionary changes in embryonic patterning and provide an efficient way to identify likely candidate regulatory interactions for subsequent experimental validation.
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Affiliation(s)
- Abdull J Massri
- Department of Biology, Duke University, Durham, NC 27708, USA
| | | | - Anton Afanassiev
- Department of Mathematics, University of British Colombia, Vancouver, BC, Canada V6T 1Z2
| | - Laura Greenstreet
- Department of Mathematics, University of British Colombia, Vancouver, BC, Canada V6T 1Z2
| | - Krista Pipho
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Maria Byrne
- School of Life and Environmental Sciences, Sydney University, Sydney, NSW, Australia
| | - Geoffrey Schiebinger
- Department of Mathematics, University of British Colombia, Vancouver, BC, Canada V6T 1Z2
| | - David R McClay
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Gregory A Wray
- Department of Biology, Duke University, Durham, NC 27708, USA
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7
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Lhomond G, Schubert M, Croce J. Spatiotemporal requirements of nuclear β-catenin define early sea urchin embryogenesis. PLoS Biol 2024; 22:e3002880. [PMID: 39531468 DOI: 10.1371/journal.pbio.3002880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 12/20/2024] [Accepted: 10/04/2024] [Indexed: 11/16/2024] Open
Abstract
Establishment of the 3 primordial germ layers (ectoderm, endoderm, and mesoderm) during early animal development represents an essential prerequisite for the emergence of properly patterned embryos. β-catenin is an ancient protein that is known to play essential roles in this process. However, these roles have chiefly been established through inhibition of β-catenin translation or function at the time of fertilization. Comprehensive analyses reporting the totality of functions played by nuclear β-catenin during early embryogenesis of a given animal, i.e., at different developmental stages and in different germ layers, are thus still lacking. In this study, we used an inducible, conditional knockdown system in the sea urchin to characterize all possible requirements of β-catenin for germ layer establishment and patterning. By blocking β-catenin protein production starting at 7 different time points of early development, between fertilization and 12 h post fertilization, we established a clear correlation between the position of a germ layer along the primary embryonic axis (the animal-vegetal axis) and its dependence on nuclear β-catenin activity. For example, in the vegetal hemisphere, we determined that the 3 germ layers (skeletogenic mesoderm, non-skeletogenic mesoderm, and endoderm) require distinct and highly specific durations of β-catenin production for their respective specification, with the most vegetal germ layer, the skeletogenic mesoderm, requiring the shortest duration. Likewise, for the 2 animal territories (ectoderm and anterior neuroectoderm), we established that their restriction, along the animal-vegetal axis, relies on different durations of β-catenin production and that the longest duration is required for the most animal territory, the anterior neuroectoderm. Moreover, we found that 2 of the vegetal germ layers, the non-skeletogenic mesoderm and the endoderm, further require a prolonged period of nuclear β-catenin activity after their specification to maintain their respective germ layer identities through time. Finally, we determined that restriction of the anterior neuroectoderm territory depends on at least 2 nuclear β-catenin-dependent inputs and a nuclear β-catenin-independent mechanism. Taken together, this work is the first to comprehensively define the spatiotemporal requirements of β-catenin during the early embryogenesis of a single animal, the sea urchin Paracentrotus lividus, thereby providing new experimental evidence for a better understanding of the roles played by this evolutionary conserved protein during animal development.
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Affiliation(s)
- Guy Lhomond
- Sorbonne Université, CNRS, Institut de la Mer de Villefranche (IMEV), Laboratoire de Biologie du Développement de Villefranche-sur-Mer (LBDV), Evolution of Intercellular Signaling in Development (EvoInSiDe), Villefranche-sur-Mer, France
| | - Michael Schubert
- Sorbonne Université, CNRS, Institut de la Mer de Villefranche (IMEV), Laboratoire de Biologie du Développement de Villefranche-sur-Mer (LBDV), Evolution of Intercellular Signaling in Development (EvoInSiDe), Villefranche-sur-Mer, France
| | - Jenifer Croce
- Sorbonne Université, CNRS, Institut de la Mer de Villefranche (IMEV), Laboratoire de Biologie du Développement de Villefranche-sur-Mer (LBDV), Evolution of Intercellular Signaling in Development (EvoInSiDe), Villefranche-sur-Mer, France
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8
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Tate HM, Barone V, Schrankel CS, Hamdoun A, Lyons DC. Localization and origins of juvenile skeletogenic cells in the sea urchin Lytechinuspictus. Dev Biol 2024; 514:12-27. [PMID: 38862087 DOI: 10.1016/j.ydbio.2024.05.012] [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: 07/22/2023] [Revised: 05/10/2024] [Accepted: 05/16/2024] [Indexed: 06/13/2024]
Abstract
The development of the sea urchin larval body plan is well understood from extensive studies of embryonic patterning. However, fewer studies have investigated the late larval stages during which the unique pentaradial adult body plan develops. Previous work on late larval development highlights major tissue changes leading up to metamorphosis, but the location of specific cell types during juvenile development is less understood. Here, we improve on technical limitations by applying highly sensitive hybridization chain reaction fluorescent in situ hybridization (HCR-FISH) to the fast-developing and transparent sea urchin Lytechinus pictus, with a focus on skeletogenic cells. First, we show that HCR-FISH can be used in L. pictus to precisely localize skeletogenic cells in the rudiment. In doing so, we provide a detailed staging scheme for the appearance of skeletogenic cells around the rudiment prior to and during biomineralization and show that many skeletogenic cells unassociated with larval rods localize outside of the rudiment prior to localizing inside. Second, we show that downstream biomineralization genes have similar expression patterns during larval and juvenile skeletogenesis, suggesting some conservation of skeletogenic mechanisms during development between stages. Third, we find co-expression of blastocoelar and skeletogenic cell markers around juvenile skeleton located outside of the rudiment, which is consistent with data showing that cells from the non-skeletogenic mesoderm embryonic lineage contribute to the juvenile skeletogenic cell lineage. This work sets the foundation for subsequent studies of other cell types in the late larva of L. pictus to better understand juvenile body plan development, patterning, and evolution.
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Affiliation(s)
- Heidi M Tate
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, USA
| | - Vanessa Barone
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, USA
| | - Catherine S Schrankel
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, USA; San Diego State University, San Diego, CA, USA
| | - Amro Hamdoun
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, USA
| | - Deirdre C Lyons
- Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, USA.
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El Ayari T, Ben Ahmed R, Bouriga N, Gravato C, Chelbi E, Nechi S, El Menif NT. Florfenicol induces malformations of embryos and causes altered lipid profile, oxidative damage, neurotoxicity, and histological effects on gonads of adult sea urchin, Paracentrotus lividus. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2024; 110:104533. [PMID: 39127436 DOI: 10.1016/j.etap.2024.104533] [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: 04/03/2024] [Accepted: 08/08/2024] [Indexed: 08/12/2024]
Abstract
The frequent occurrence of antibiotics in the aquatic environment has engendered negative impacts on non-target organisms. The effects of the veterinary antibiotic florfenicol (FLO) during the embryo-larval development of the sea urchin, Paracentrotus lividus was assessed using four increasing concentrations (1, 2, 5 and 10 mg/L). Furthermore, FLO toxicity to adults was investigated through the analysis of oxidative damage, histopathological alterations, lipid metabolism and acetylcholinesterase activity following an exposure period of 96 h. FLO induced embryotoxicity with estimated EC50 values of 5.75, 7.56 and 3.29 mg/L after 12 h, 24 h and 48 h, respectively. It generated oxidative stress assessed as lipid peroxidation in gonads despite the increased antioxidant activity of catalase (CAT). Neurotoxicity was also evident since the AChE activity significantly decreased. Moreover, FLO affected the lipid metabolism by increasing saturated fatty acid (SFA) and monounsaturated fatty acid proportions (MUFA), except in the group exposed to 5 mg/L. The increase in polyunsaturated fatty acid (PUFA) levels and docosahexaenoic acid (DHA, C22:6n-3) proportions were noted with all FLO concentrations. Eicosapentaenoic acid (EPA, C20:5n-3) decreased, while arachidonic acid (ARA, C20:4n-6) increased in sea urchins exposed to 5 and 10 mg/L FLO. Histopathological alterations of gonadal tissues represent an additional confirmation about the toxicity of this antibiotic that might decrease the reproductive performance of this species. Nevertheless, even if reproduction of sea urchins would be partially successful, the embryotoxicity would compromise the normal development of the embryos with consequences on the population.
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Affiliation(s)
- Tahani El Ayari
- Group of Fundamental and Applied Malacology (MAF), Laboratory of Environment Bio-monitoring (LBE), Faculty of Sciences of Bizerte, University of Carthage, Bizerte, Zarzouna 7021, Tunisia.
| | - Raja Ben Ahmed
- University of El Manar, Faculty of Sciences of Tunis, Department of Biology, Ecology, Biology and physiology of Aquatic Organisms Laboratory, Tunis, Tunisia
| | - Nawzet Bouriga
- University of El Manar, Faculty of Sciences of Tunis, Department of Biology, Ecology, Biology and physiology of Aquatic Organisms Laboratory, Tunis, Tunisia; Higher Institute of Fisheries and Aquaculture of Bizerte, University of Carthage., Errimel B.P.15, Bizerte 7080, Tunisia
| | - Carlos Gravato
- Centre for Ecology, Evolution and Environmental Changes (cE3c) & CHANGE - Global Change and Sustainability Institute, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Lisboa 1749-016, Portugal; Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Lisboa 1749-016, Portugal
| | - Emna Chelbi
- Anatomy and Cytology Service, CHU Mohamed Taher Maamouri Hospital, University Tunis El Manar, Tunis 2092, Tunisia
| | - Salwa Nechi
- Anatomy and Cytology Service, CHU Mohamed Taher Maamouri Hospital, University Tunis El Manar, Tunis 2092, Tunisia
| | - Najoua Trigui El Menif
- Group of Fundamental and Applied Malacology (MAF), Laboratory of Environment Bio-monitoring (LBE), Faculty of Sciences of Bizerte, University of Carthage, Bizerte, Zarzouna 7021, Tunisia
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10
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Clarke DN, Formery L, Lowe CJ. See-Star: a versatile hydrogel-based protocol for clearing large, opaque and calcified marine invertebrates. EvoDevo 2024; 15:8. [PMID: 38918798 PMCID: PMC11201320 DOI: 10.1186/s13227-024-00228-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 05/28/2024] [Indexed: 06/27/2024] Open
Abstract
Studies of morphology and developmental patterning in adult stages of many invertebrates are hindered by opaque structures, such as shells, skeletal elements, and pigment granules that block or refract light and necessitate sectioning for observation of internal features. An inherent challenge in studies relying on surgical approaches is that cutting tissue is semi-destructive, and delicate structures, such as axonal processes within neural networks, are computationally challenging to reconstruct once disrupted. To address this problem, we developed See-Star, a hydrogel-based tissue clearing protocol to render the bodies of opaque and calcified invertebrates optically transparent while preserving their anatomy in an unperturbed state, facilitating molecular labeling and observation of intact organ systems. The resulting protocol can clear large (> 1 cm3) specimens to enable deep-tissue imaging, and is compatible with molecular techniques, such as immunohistochemistry and in situ hybridization to visualize protein and mRNA localization. To test the utility of this method, we performed a whole-mount imaging study of intact nervous systems in juvenile echinoderms and molluscs and demonstrate that See-Star allows for comparative studies to be extended far into development, facilitating insights into the anatomy of juveniles and adults that are usually not amenable to whole-mount imaging.
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Affiliation(s)
- D N Clarke
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - L Formery
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, USA
| | - C J Lowe
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
- Chan Zuckerberg BioHub, San Francisco, CA, USA
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11
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Wilkie IC. Basement Membranes, Brittlestar Tendons, and Their Mechanical Adaptability. BIOLOGY 2024; 13:375. [PMID: 38927255 PMCID: PMC11200632 DOI: 10.3390/biology13060375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 05/20/2024] [Accepted: 05/21/2024] [Indexed: 06/28/2024]
Abstract
Basement membranes (BMs) are thin layers of extracellular matrix that separate epithelia, endothelia, muscle cells, and nerve cells from adjacent interstitial connective tissue. BMs are ubiquitous in almost all multicellular animals, and their composition is highly conserved across the Metazoa. There is increasing interest in the mechanical functioning of BMs, including the involvement of altered BM stiffness in development and pathology, particularly cancer metastasis, which can be facilitated by BM destabilization. Such BM weakening has been assumed to occur primarily through enzymatic degradation by matrix metalloproteinases. However, emerging evidence indicates that non-enzymatic mechanisms may also contribute. In brittlestars (Echinodermata, Ophiuroidea), the tendons linking the musculature to the endoskeleton consist of extensions of muscle cell BMs. During the process of brittlestar autotomy, in which arms are detached for the purpose of self-defense, muscles break away from the endoskeleton as a consequence of the rapid destabilization and rupture of their BM-derived tendons. This contribution provides a broad overview of current knowledge of the structural organization and biomechanics of non-echinoderm BMs, compares this with the equivalent information on brittlestar tendons, and discusses the possible relationship between the weakening phenomena exhibited by BMs and brittlestar tendons, and the potential translational value of the latter as a model system of BM destabilization.
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Affiliation(s)
- Iain C Wilkie
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow G12 8QQ, UK
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Gambardella C, Miroglio R, Prieto Amador M, Castelli F, Castellano L, Piazza V, Faimali M, Garaventa F. High concentrations of phthalates affect the early development of the sea urchin Paracentrotus lividus. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 279:116473. [PMID: 38781890 DOI: 10.1016/j.ecoenv.2024.116473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 04/29/2024] [Accepted: 05/15/2024] [Indexed: 05/25/2024]
Abstract
The toxicity of three phthalates (PAEs) - butylbenzyl phthalate (BBP), diethyl phthalate (DEP), and di-(2-ethylhexyl) phthalate (DEHP) - was tested on the Mediterranean sea urchin Paracentrotus lividus. Fertilized eggs were exposed to environmental and high PAE concentrations for 72 h. The potential toxic effects on larval development and any morphological anomalies were then assessed to estimate PAEs impact. Environmental concentrations never affected development, while high concentrations induced toxic effects in larvae exposed to BBP (EC50: 2.9 ×103 µg/L) and DEHP (EC50: 3.72 ×103 µg/L). High concentrations caused skeletal anomalies, with a slight to moderate impact for DEP/DEHP and BBP, respectively. PAE toxicity was: BBP>DEHP>DEP. In conclusion, the three PAEs at environmental concentrations do not pose a risk to sea urchins. However, PAE concentrations should be further monitored in order not to constitute a concern to marine species, especially at their early developmental stages.
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Affiliation(s)
- Chiara Gambardella
- CNR-IAS, via de Marini 6, Genova 16149, Italy; National Biodiversity Future Center (NBFC) S.c.a.r.l., Piazza Marina 61 (c/o palazzo Steri), Palermo, Italy.
| | - Roberta Miroglio
- CNR-IAS, via de Marini 6, Genova 16149, Italy; National Biodiversity Future Center (NBFC) S.c.a.r.l., Piazza Marina 61 (c/o palazzo Steri), Palermo, Italy
| | | | | | - Laura Castellano
- Costa Edutainment SpA - Acquario di Genova, Area Porto Antico, Ponte Spinola, Genoa 16128, Italy
| | | | - Marco Faimali
- CNR-IAS, via de Marini 6, Genova 16149, Italy; National Biodiversity Future Center (NBFC) S.c.a.r.l., Piazza Marina 61 (c/o palazzo Steri), Palermo, Italy
| | - Francesca Garaventa
- CNR-IAS, via de Marini 6, Genova 16149, Italy; National Biodiversity Future Center (NBFC) S.c.a.r.l., Piazza Marina 61 (c/o palazzo Steri), Palermo, Italy
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Massri AJ, Berrio A, Afanassiev A, Greenstreet L, Pipho K, Byrne M, Schiebinger G, McClay DR, Wray GA. Single-cell transcriptomics reveals evolutionary reconfiguration of embryonic cell fate specification in the sea urchin Heliocidaris erythrogramma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.30.591752. [PMID: 38746376 PMCID: PMC11092583 DOI: 10.1101/2024.04.30.591752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Altered regulatory interactions during development likely underlie a large fraction of phenotypic diversity within and between species, yet identifying specific evolutionary changes remains challenging. Analysis of single-cell developmental transcriptomes from multiple species provides a powerful framework for unbiased identification of evolutionary changes in developmental mechanisms. Here, we leverage a "natural experiment" in developmental evolution in sea urchins, where a major life history switch recently evolved in the lineage leading to Heliocidaris erythrogramma, precipitating extensive changes in early development. Comparative analyses of scRNA-seq developmental time courses from H. erythrogramma and Lytechinus variegatus (representing the derived and ancestral states respectively) reveals numerous evolutionary changes in embryonic patterning. The earliest cell fate specification events, and the primary signaling center are co-localized in the ancestral dGRN but remarkably, in H. erythrogramma they are spatially and temporally separate. Fate specification and differentiation are delayed in most embryonic cell lineages, although in some cases, these processes are conserved or even accelerated. Comparative analysis of regulator-target gene co-expression is consistent with many specific interactions being preserved but delayed in H. erythrogramma, while some otherwise widely conserved interactions have likely been lost. Finally, specific patterning events are directly correlated with evolutionary changes in larval morphology, suggesting that they are directly tied to the life history shift. Together, these findings demonstrate that comparative scRNA-seq developmental time courses can reveal a diverse set of evolutionary changes in embryonic patterning and provide an efficient way to identify likely candidate regulatory interactions for subsequent experimental validation.
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Affiliation(s)
- Abdull J Massri
- Department of Biology, Duke University, Durham, NC 27701 USA
| | | | - Anton Afanassiev
- Department of Mathematics, University of British Colombia, Vancouver, BC V6T 1Z4 Canada
| | - Laura Greenstreet
- Department of Mathematics, University of British Colombia, Vancouver, BC V6T 1Z4 Canada
| | - Krista Pipho
- Department of Biology, Duke University, Durham, NC 27701 USA
| | - Maria Byrne
- School of Life and Environmental Sciences, Sydney University, Sydney, NSW Australia
| | - Geoffrey Schiebinger
- Department of Mathematics, University of British Colombia, Vancouver, BC V6T 1Z4 Canada
| | - David R McClay
- Department of Biology, Duke University, Durham, NC 27701 USA
| | - Gregory A Wray
- Department of Biology, Duke University, Durham, NC 27701 USA
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Cocurullo M, Paganos P, Benvenuto G, Arnone MI. Characterization of thyrotropin-releasing hormone producing neurons in sea urchin, from larva to juvenile. Front Neurosci 2024; 18:1378520. [PMID: 38660219 PMCID: PMC11039832 DOI: 10.3389/fnins.2024.1378520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 03/27/2024] [Indexed: 04/26/2024] Open
Abstract
Most sea urchin species are indirect developers, going through a larval stage called pluteus. The pluteus possesses its own nervous system, consisting mainly of the apical organ neurons (controlling metamorphosis and settlement) and ciliary band neurons (controlling swimming behavior and food collection). Additional neurons are located in various areas of the gut. In recent years, the molecular complexity of this apparently "simple" nervous system has become apparent, with at least 12 neuronal populations identified through scRNA-sequencing in the species Strongylocentrotus purpuratus. Among these, there is a cluster of neurosecretory cells that produce a thyrotropin-releasing hormone-type neuropeptide (TRHergic) and that are also photosensory (expressing a Go-Opsin). However, much less is known about the organization of the nervous system in other sea urchin species. The aim of this work was to thoroughly characterize the localization of the TRHergic cells from early pluteus to juvenile stages in the Mediterranean sea urchin species Paracentrotus lividus combining immunostaining and whole mount in situ hybridization. We also compared the localization of TRHergic cells in early plutei of two other sea urchin species, Arbacia lixula and Heliocidaris tuberculata. This work provides new information on the anatomy and development of the nervous system in sea urchins. Moreover, by comparing the molecular signature of the TRHergic cells in P. lividus and S. purpuratus, we have obtained new insights how TRH-type neuropeptide signaling evolved in relatively closely related species.
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Affiliation(s)
| | | | | | - Maria Ina Arnone
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
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