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John R Finnerty - One of the best experts on this subject based on the ideXlab platform.
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A report from the second Nematostella vectensis research conference
Development Genes and Evolution, 2013Co-Authors: Thomas D Gilmore, Ann M Tarrant, John R FinnertyAbstract:This report summarizes information discussed at the second Nematostella vectensis research conference, which took place on August 27, 2012 in Boston, MA, USA. The startlet sea anemone Nematostella is emerging as one of leading model organisms among cnidarians, in part because of the extensive genome and transcriptome resources that are becoming available for Nematostella , which were the focus of several presentations. In addition, research was presented on the use of Nematostella in developmental, regeneration, signal transduction, host–symbiont, and gene–environment interaction studies.
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isolation of dna rna and protein from the starlet sea anemone Nematostella vectensis
Nature Protocols, 2013Co-Authors: Derek J Stefanik, Francis S Wolenski, Thomas D Gilmore, Lauren E Friedman, John R FinnertyAbstract:Among marine invertebrates, the starlet sea anemone Nematostella vectensis has emerged as an important laboratory model system. One advantage of working with this species relative to many other marine invertebrates is the ease of isolating relatively pure DNA, RNA and protein. Nematostella can be raised at high densities, under clean culture conditions, and it lacks integumentary or skeletal structures that can impede the recovery of DNA, RNA or protein. Here we describe methods used in our lab to isolate DNA, RNA and protein from Nematostella embryos, larvae and adults. The methods described here are less expensive than commercial kits and are more easily scalable to larger tissue amounts. Preparation of DNA can be completed in ∼7 h, RNA preparation in ∼1.5 h and protein preparation in ∼1 h.
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Collecting, rearing, spawning and inducing regeneration of the starlet sea anemone, Nematostella vectensis
Nature Protocols, 2013Co-Authors: Derek J Stefanik, Lauren E Friedman, John R FinnertyAbstract:Over the past 20 years, the starlet sea anemone, Nematostella vectensis , a small estuarine animal, has emerged as a powerful model system for field and laboratory studies of development, evolution, genomics, molecular biology and toxicology. Here we describe how to collect Nematostella , culture it through its entire sexual life cycle and induce regeneration for the production of clonal stocks. In less than 1 h at a suitable field site, a researcher on foot can collect hundreds of individual anemones. In a few months, it is possible to establish a laboratory colony that will be reliable in generating hundreds or thousands of fertilized eggs on a roughly weekly schedule. By inducing regeneration roughly every 2 weeks, in less than 6 months, one can establish a clonal stock consisting of hundreds of genetically identical anemones. These results can be achieved very inexpensively and without specialized equipment.
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characterizing the spatiotemporal expression of rnas and proteins in the starlet sea anemone Nematostella vectensis
Nature Protocols, 2013Co-Authors: Francis S Wolenski, Michael J Layden, Thomas D Gilmore, Mark Q. Martindale, John R FinnertyAbstract:In an effort to reconstruct the early evolution of animal genes and proteins, there is an increasing focus on basal animal lineages such as sponges, cnidarians, ctenophores and placozoans. Among the basal animals, the starlet sea anemone Nematostella vectensis (phylum Cnidaria) has emerged as a leading laboratory model organism partly because it is well suited to experimental techniques for monitoring and manipulating gene expression. Here we describe protocols adapted for use in Nematostella to characterize the expression of RNAs by in situ hybridization using either chromogenic or fluorescence immunohistochemistry (∼1 week), as well as to characterize protein expression by whole-mount immunofluorescence (∼3 d). We also provide a protocol for labeling cnidocytes (∼3 h), the phylum-specific sensory-effector cell type that performs a variety of functions in cnidarians, including the delivery of their venomous sting.
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Figure 7
2013Co-Authors: Joseph F Ryan, Maureen E Mazza, Kevin Pang, David Q. Matus, Andreas D. Baxevanis, Mark Q. Martindale, John R FinnertyAbstract:Hox/ParaHox evolutionary scenarios. The phylogenies drawn here depict six mutually exclusive scenarios regarding the evolution of the Hox and ParaHox genes. Ten distinct Hox and ParaHox lineages are thought to have been present in the ancestral bilaterian (Hox1, Hox2, Hox3, Hox4, Hox5, Hox6–8, Hox9+, Cdx, Gsx, and Xlox). Five distinct Hox/ParaHox lineages are recognized for Nematostella. (Nematostella homeodomains that tend to cluster together in the phylogenetic analyses are grouped together here: anthox1/1a; anthox2/9; anthox6/6a; anthox7/8a/8b.) Assuming no gene loss in the Cnidaria, then the existence of five Hox/ParaHox lineages in Nematostella implies that the cnidarian-bilaterian ancestor (CBA) could have possessed as few as one Hox/ParaHox gene (scenario A) or as many as five (scenario E). There is some indication that a central class Hox gene was lost in the Cnidaria [47], and that the CBA may have possessed six distinct Hox/ParaHox genes (scenario F). The ancestral Hox/ParaHox genes present in the CBA are indicated by solid squares. If a particular hypothetical clade is recovered on one or more of the phylogenetic analyses presented here, this is indicated above the relevant branch (NJ = neighbor-joining, Figure 2; Ba = Bayesian inference, Figure S1; ML = maximum- likelihood, Figure S2; φ = none). Below each branch, the average statistical support is indicated (NJ-bootstrap proportion+Bayes-posterior probability+ML-boostrap proportion/3). Each scenario implies a different number of lineage-specific gene losses.
Ulrich Technau - One of the best experts on this subject based on the ideXlab platform.
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Generating Transgenic Reporter Lines for Studying Nervous System Development in the Cnidarian Nematostella vectensis.
Methods in molecular biology (Clifton N.J.), 2019Co-Authors: Fabian Rentzsch, Eduard Renfer, Ulrich TechnauAbstract:Neurons often display complex morphologies with long and fine processes that can be difficult to visualize, in particular in living animals. Transgenic reporter lines in which fluorescent proteins are expressed in defined populations of neurons are important tools that can overcome these difficulties. By using membrane-attached fluorescent proteins, such reporter transgenes can identify the complete outline of subsets of neurons or they can highlight the subcellular localization of fusion proteins, for example at pre- or postsynaptic sites. The relative stability of fluorescent proteins furthermore allows the tracing of the progeny of cells over time and can therefore provide information about potential roles of the gene whose regulatory elements are controlling the expression of the fluorescent protein. Here we describe the generation of transgenic reporter lines in the sea anemone Nematostella vectensis, a cnidarian model organism for studying the evolution of developmental processes. We also provide an overview of existing transgenic Nematostella lines that have been used to study conserved and derived aspects of nervous system development.
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Characterization of the piRNA pathway during development of the sea anemone Nematostella vectensis
RNA biology, 2017Co-Authors: Daniela Praher, Vengamanaidu Modepalli, Yehu Moran, Bob Zimmermann, Yaara Y. Columbus-shenkar, Grigory Genikhovich, Reuven Aharoni, Ulrich TechnauAbstract:PIWI-interacting RNAs (piRNAs) and associated proteins comprise a conserved pathway for silencing transposons in metazoan germlines. piRNA pathway components are also expressed in multipotent somatic stem cells in various organisms. piRNA functions have been extensively explored in bilaterian model systems, however, comprehensive studies in non-bilaterian phyla remain limited. Here we investigate the piRNA pathway during the development of Nematostella vectensis, a well-established model system belonging to Cnidaria, the sister group to Bilateria. To date, no population of somatic stem cells has been identified in this organism, despite its long life-span and regenerative capacities that require a constant cell-renewal. We show that Nematostella piRNA pathway components are broadly expressed in early developmental stages, while piRNAs themselves show differential expression, suggesting specific developmental roles of distinct piRNA families. In adults, piRNA associated proteins are enriched in the germline but also expressed in somatic cells, indicating putative stem cell properties. Furthermore, we provide experimental evidence that Nematostella piRNAs cleave transposable elements as well as protein-coding genes. Our results demonstrate that somatic expression of piRNA associated proteins as well as the roles of piRNAs in transposon repression and gene regulation are likely ancestral features that evolved before the split between Cnidaria and Bilateria.
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Response of bacterial colonization in Nematostella vectensis to development, environment and biogeography.
Environmental microbiology, 2015Co-Authors: Benedikt M Mortzfeld, Ulrich Technau, Adam M Reitzel, Szymon Urbanski, Sven Künzel, Sebastian FrauneAbstract:Summary The establishment of host–bacterial colonization during development is a fundamental process influencing the fitness of many organisms, but the factors controlling community membership and influencing the establishment of the microbial ecosystem during development are poorly understood. The starlet sea anemone Nematostella vectensis serves as a cnidarian model organism due to the availability of laboratory cultures and its high tolerance for broad ranges of salinity and temperature. Here, we show that the anemone's epithelia are colonized by diverse bacterial communities and that the composition of its microbiota is tightly coupled to host development. Environmental variations led to robust adjustments in the microbial composition while still maintaining the ontogenetic core signature. In addition, analysis of bacterial communities of Nematostella polyps from five different populations revealed a strong correlation between host biogeography and bacterial diversity despite years of laboratory culturing. These observed variations in fine-scale community composition following environmental change and for individuals from different geographic origins could represent the microbiome's contribution to host acclimation and potentially adaptation, respectively, and thereby contribute to the maintenance of homeostasis due to environmental changes.
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Axis Patterning by BMPs: Cnidarian Network Reveals Evolutionary Constraints
Elsevier, 2015Co-Authors: Grigory Genikhovich, David Fredman, Patrick Fried, M. mandela Prünster, Johannes b. Schinko, Anna f. Gilles, Karin Meier, Dagmar Iber, Ulrich TechnauAbstract:BMP signaling plays a crucial role in the establishment of the dorso-ventral body axis in bilaterally symmetric animals. However, the topologies of the bone morphogenetic protein (BMP) signaling networks vary drastically in different animal groups, raising questions about the evolutionary constraints and evolvability of BMP signaling systems. Using loss-of-function analysis and mathematical modeling, we show that two signaling centers expressing different BMPs and BMP antagonists maintain the secondary axis of the sea anemone Nematostella. We demonstrate that BMP signaling is required for asymmetric Hox gene expression and mesentery formation. Computational analysis reveals that network parameters related to BMP4 and Chordin are constrained both in Nematostella and Xenopus, while those describing the BMP signaling modulators can vary significantly. Notably, only chordin, but not bmp4 expression needs to be spatially restricted for robust signaling gradient formation. Our data provide an explanation of the evolvability of BMP signaling systems in axis formation throughout Eumetazoa
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Current directions and future perspectives from the third Nematostella research conference.
Zoology (Jena Germany), 2014Co-Authors: Ann M Tarrant, Ulrich Technau, Adam M Reitzel, Thomas D Gilmore, Oren Levy, Mark Q. MartindaleAbstract:The third Nematostella vectensis Research Conference took place in December 2013 in Eilat, Israel, as a satellite to the 8th International Conference on Coelenterate Biology. The starlet sea anemone, N. vectensis, has emerged as a powerful cnidarian model, in large part due to the extensive genomic and transcriptomic resources and molecular approaches that are becoming available for Nematostella, which were the focus of several presentations. In addition, research was presented highlighting the broader utility of this species for studies of development, circadian rhythms, signal transduction, and gene–environment interactions.
Eric Röttinger - One of the best experts on this subject based on the ideXlab platform.
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The sea anemone Nematostella vectensis, an emerging model for biomedical research: Mechano-sensitivity, extreme regeneration and longevity
Medecine sciences : M S, 2021Co-Authors: Aldine R. Amiel, Vincent Michel, João E. Carvalho, Marina Shkreli, Christine Petit, Eric RöttingerAbstract:Nematostella has fascinating features such as whole-body regeneration, the absence of signs of aging and importantly, the absence of age-related diseases. Easy to culture and spawn, this little sea anemone in spite of its "simple" aspect, displays interesting morphological characteristics similar to vertebrates and an unexpected similarity in gene content/genome organization. Importantly, the scientific community working on Nematostella is developing a variety of functional genomics tools that enable scientists to use this anemone in the field of regenerative medicine, longevity and mecano-sensory diseases. As a complementary research model to vertebrates, this marine invertebrate is emerging and promising to dig deeper into those fields of research in an integrative manner (entire organism) and provides new opportunities for scientists to lift specific barriers that can be encountered with other commonly used animal models.
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L’anémone de mer Nematostella vectensis
médecine sciences, 2021Co-Authors: Aldine R. Amiel, Vincent Michel, João E. Carvalho, Marina Shkreli, Christine Petit, Eric RöttingerAbstract:Nematostella, petite anémone de mer, possède de fascinantes propriétés, telles que la régénération du corps entier, l’absence de signes de vieillissement et d’affections liées à l’âge comme, par exemple, le développement de cancers. Elle se cultive aisément et se reproduit en laboratoire. Malgré son aspect « simple », cet invertébré marin de l’embranchement des cnidaires partage avec les vertébrés des caractéristiques non seulement morphologiques, mais également génomiques. La communauté scientifique développe aujourd’hui une variété d’outils de génomique fonctionnelle permettant l’utilisation de cet animal de façon intégrative dans le domaine de la médecine régénérative, de la longévité et des maladies mécano-sensorielles. Son étude se présente comme particulièrement prometteuse pour faire progresser la connaissance dans ces différents domaines, offrant des possibilités expérimentales qui font défaut dans les modèles animaux classiques.
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Transcriptomic Analysis in the Sea Anemone Nematostella vectensis.
Methods in Molecular Biology, 2020Co-Authors: Jacob F. Warner, Eric RöttingerAbstract:The sea anemone Nematostella vectensis is an emerging research model to study embryonic development and regeneration at the molecular and global transcriptomic level. Transcriptomics analysis is now routinely used to detect differential expression at the genome level. Here we present the latest procedures for isolating high-quality RNA required for next generation sequencing, as well as methods and resources for quantifying transcriptomic data.
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nvertx a gene expression database to compare embryogenesis and regeneration in the sea anemone Nematostella vectensis
bioRxiv, 2018Co-Authors: Jacob F. Warner, Aldine R. Amiel, Hereroa Johnston, Karine Nedoncelle, Vincent Guerlais, Eric RöttingerAbstract:For more than a century researchers have been comparing embryogenesis and regeneration hoping that lessons learned from embryonic development will unlock hidden regenerative potential. This problem has historically been a difficult one to investigate since the best regenerative model systems are poor embryonic models and vice versa. Recently however, the comparison of embryogenesis and regeneration has seen renewed interest as emerging models including the sea anemone Nematostella vectensis have allowed researchers to investigate these processes in the same organism. This interest has been further fueled by the advent of high-throughput transcriptomic analyses that provide virtual mountains of data. Unfortunately much of this data remains in raw unanalyzed formats that are difficult to access or browse. Here we present Nematostella vectensis Embryogenesis and Regeneration Transcriptomics - NvERTx, the first platform for comparing gene expression during embryogenesis and regeneration. NvERTx is comprised of close to 50 RNAseq datasets spanning embryogenesis and regeneration in Nematostella. These data were used to perform a robust de novo transcriptome assembly which users can search, BLAST and plot expression of multiple genes during these two developmental processes. The site is also home to the results of gene clustering analyses, to further mine the data and identify groups of co-expressed genes. The site can be accessed at http://nvertx.kahikai.org.
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nvertx a gene expression database to compare embryogenesis and regeneration in the sea anemone Nematostella vectensis
Development, 2018Co-Authors: Jacob F. Warner, Aldine R. Amiel, Hereroa Johnston, Karine Nedoncelle, Vincent Guerlais, Eric RöttingerAbstract:For over a century, researchers have been comparing embryogenesis and regeneration hoping that lessons learned from embryonic development will unlock hidden regenerative potential. This problem has historically been a difficult one to investigate because the best regenerative model systems are poor embryonic models and vice versa. Recently, however, there has been renewed interest in this question, as emerging models have allowed researchers to investigate these processes in the same organism. This interest has been further fueled by the advent of high-throughput transcriptomic analyses that provide virtual mountains of data. Here, we present Nematostella vectensis Embryogenesis and Regeneration Transcriptomics (NvERTx), a platform for comparing gene expression during embryogenesis and regeneration. NvERTx consists of close to 50 transcriptomic data sets spanning embryogenesis and regeneration in Nematostella These data were used to perform a robust de novo transcriptome assembly, with which users can search, conduct BLAST analyses, and plot the expression of multiple genes during these two developmental processes. The site is also home to the results of gene clustering analyses, to further mine the data and identify groups of co-expressed genes. The site can be accessed at http://nvertx.kahikai.org.
Mark Q. Martindale - One of the best experts on this subject based on the ideXlab platform.
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Do novel genes drive morphological novelty? An investigation of the nematosomes in the sea anemone Nematostella vectensis.
BMC evolutionary biology, 2016Co-Authors: Leslie S. Babonis, Mark Q. Martindale, Joseph F RyanAbstract:The evolution of novel genes is thought to be a critical component of morphological innovation but few studies have explicitly examined the contribution of novel genes to the evolution of novel tissues. Nematosomes, the free-floating cellular masses that circulate through the body cavity of the sea anemone Nematostella vectensis, are the defining apomorphy of the genus Nematostella and are a useful model for understanding the evolution of novel tissues. Although many hypotheses have been proposed, the function of nematosomes is unknown. To gain insight into their putative function and to test hypotheses about the role of lineage-specific genes in the evolution of novel structures, we have re-examined the cellular and molecular biology of nematosomes. Using behavioral assays, we demonstrate that nematosomes are capable of immobilizing live brine shrimp (Artemia salina) by discharging their abundant cnidocytes. Additionally, the ability of nematosomes to engulf fluorescently labeled bacteria (E. coli) reveals the presence of phagocytes in this tissue. Using RNA-Seq, we show that the gene expression profile of nematosomes is distinct from that of the tentacles and the mesenteries (their tissue of origin) and, further, that nematosomes (a Nematostella-specific tissue) are enriched in Nematostella-specific genes. Despite the small number of cell types they contain, nematosomes are distinct among tissues, both functionally and molecularly. We provide the first evidence that nematosomes comprise part of the innate immune system in N. vectensis, and suggest that this tissue is potentially an important place to look for genes associated with pathogen stress. Finally, we demonstrate that Nematostella-specific genes comprise a significant proportion of the differentially expressed genes in all three of the tissues we examined and may play an important role in novel cell functions.
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In vivo imaging of Nematostella vectensis embryogenesis and late development using fluorescent probes
BMC cell biology, 2014Co-Authors: Timothy Q. Dubuc, Eric Röttinger, Mark Q. Martindale, Ada Dattoli, Miguel Salinas-saavedra, Leslie S. Babonis, Marten PostmaAbstract:Cnidarians are the closest living relatives to bilaterians and have been instrumental to studying the evolution of bilaterian properties. The cnidarian model, Nematostella vectensis, is a unique system in which embryology and regeneration are both studied, making it an ideal candidate to develop in vivo imaging techniques. Live imaging is the most direct way for quantitative and qualitative assessment of biological phenomena. Actin and tubulin are cytoskeletal proteins universally important for regulating many embryological processes but so far studies in Nematostella primarily focused on the localization of these proteins in fixed embryos. We used fluorescent probes expressed in vivo to investigate the dynamics of Nematostella development. Lifeact-mTurquoise2, a fluorescent cyan F-actin probe, can be visualized within microvilli along the cellular surface throughout embryonic development and is stable for two months after injection. Co-expression of Lifeact-mTurquoise2 with End-Binding protein1 (EB1) fused to mVenus or tdTomato-NLS allows for the visualization of cell-cycle properties in real time. Utilizing fluorescent probes in vivo helped to identify a concentrated ‘flash’ of Lifeact-mTurquoise2 around the nucleus, immediately prior to cytokinesis in developing embryos. Moreover, Lifeact-mTurquoise2 expression in adult animals allowed the identification of various cell types as well as cellular boundaries. The methods developed in this manuscript provide an alternative protocol to investigate Nematostella development through in vivo cellular analysis. This study is the first to utilize the highly photo-stable florescent protein mTurquoise2 as a marker for live imaging. Finally, we present a clear methodology for the visualization of minute temporal events during cnidarian development.
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Current directions and future perspectives from the third Nematostella research conference.
Zoology (Jena Germany), 2014Co-Authors: Ann M Tarrant, Ulrich Technau, Adam M Reitzel, Thomas D Gilmore, Oren Levy, Mark Q. MartindaleAbstract:The third Nematostella vectensis Research Conference took place in December 2013 in Eilat, Israel, as a satellite to the 8th International Conference on Coelenterate Biology. The starlet sea anemone, N. vectensis, has emerged as a powerful cnidarian model, in large part due to the extensive genomic and transcriptomic resources and molecular approaches that are becoming available for Nematostella, which were the focus of several presentations. In addition, research was presented highlighting the broader utility of this species for studies of development, circadian rhythms, signal transduction, and gene–environment interactions.
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ectopic activation of the canonical wnt signaling pathway affects ectodermal patterning along the primary axis during larval development in the anthozoan Nematostella vectensis
Developmental Biology, 2013Co-Authors: Heather Marlow, David Q. Matus, Mark Q. MartindaleAbstract:The primary axis of cnidarians runs from the oral pole to the apical tuft and defines the major body axis of both the planula larva and adult polyp. In the anthozoan cnidarian Nematostella vectensis, the primary oral–aboral (O–Ab) axis first develops during the early embryonic stage. Here, we present evidence that pharmaceutical activators of canonical wnt signaling affect molecular patterning along the primary axis of Nematostella. Although not overtly morphologically complex, molecular investigations in Nematostella reveal that the O–Ab axis is demarcated by the expression of differentially localized signaling molecules and transcription factors that may serve roles in establishing distinct ectodermal domains. We have further characterized the larval epithelium by determining the position of a nested set of molecular boundaries, utilizing several newly characterized as well as previously reported epithelial markers along the primary axis. We have assayed shifts in their position in control embryos and in embryos treated with the pharmacological agents alsterpaullone and azakenpaullone, Gsk3β inhibitors that act as canonical wnt agonists, and the Wnt antagonist iCRT14, following gastrulation. Agonist drug treatments result in an absence of aboral markers, a shift in the expression boundaries of oral markers toward the aboral pole, and changes in the position of differentially localized populations of neurons in a dose-dependent manner, while antagonist treatment had the opposite effect. These experiments are consistent with canonical wnt signaling playing a role in an orally localized wnt signaling center. These findings suggest that in Nematostella, wnt signaling mediates O–Ab ectodermal patterning across a surprisingly complex epithelium in planula stages following gastrulation in addition to previously described roles for the wnt signaling pathway in endomesoderm specification during gastrulation and overall animal–vegetal patterning at earlier stages of anthozoan development.
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characterizing the spatiotemporal expression of rnas and proteins in the starlet sea anemone Nematostella vectensis
Nature Protocols, 2013Co-Authors: Francis S Wolenski, Michael J Layden, Thomas D Gilmore, Mark Q. Martindale, John R FinnertyAbstract:In an effort to reconstruct the early evolution of animal genes and proteins, there is an increasing focus on basal animal lineages such as sponges, cnidarians, ctenophores and placozoans. Among the basal animals, the starlet sea anemone Nematostella vectensis (phylum Cnidaria) has emerged as a leading laboratory model organism partly because it is well suited to experimental techniques for monitoring and manipulating gene expression. Here we describe protocols adapted for use in Nematostella to characterize the expression of RNAs by in situ hybridization using either chromogenic or fluorescence immunohistochemistry (∼1 week), as well as to characterize protein expression by whole-mount immunofluorescence (∼3 d). We also provide a protocol for labeling cnidocytes (∼3 h), the phylum-specific sensory-effector cell type that performs a variety of functions in cnidarians, including the delivery of their venomous sting.
Adam M Reitzel - One of the best experts on this subject based on the ideXlab platform.
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Toxin-like neuropeptides in the sea anemone Nematostella unravel recruitment from the nervous system to venom.
Proceedings of the National Academy of Sciences of the United States of America, 2020Co-Authors: Maria Y. Sachkova, Adam M Reitzel, Morani Landau, Joachim M. Surm, Jason Macrander, Shir A. Singer, Yehu MoranAbstract:The sea anemone Nematostella vectensis (Anthozoa, Cnidaria) is a powerful model for characterizing the evolution of genes functioning in venom and nervous systems. Although venom has evolved independently numerous times in animals, the evolutionary origin of many toxins remains unknown. In this work, we pinpoint an ancestral gene giving rise to a new toxin and functionally characterize both genes in the same species. Thus, we report a case of protein recruitment from the cnidarian nervous to venom system. The ShK-like1 peptide has a ShKT cysteine motif, is lethal for fish larvae and packaged into nematocysts, the cnidarian venom-producing stinging capsules. Thus, ShK-like1 is a toxic venom component. Its paralog, ShK-like2, is a neuropeptide localized to neurons and is involved in development. Both peptides exhibit similarities in their functional activities: They provoke contraction in Nematostella polyps and are toxic to fish. Because ShK-like2 but not ShK-like1 is conserved throughout sea anemone phylogeny, we conclude that the two paralogs originated due to a Nematostella-specific duplication of a ShK-like2 ancestor, a neuropeptide-encoding gene, followed by diversification and partial functional specialization. ShK-like2 is represented by two gene isoforms controlled by alternative promoters conferring regulatory flexibility throughout development. Additionally, we characterized the expression patterns of four other peptides with structural similarities to studied venom components and revealed their unexpected neuronal localization. Thus, we employed genomics, transcriptomics, and functional approaches to reveal one venom component, five neuropeptides with two different cysteine motifs, and an evolutionary pathway from nervous to venom system in Cnidaria.
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Toxin-like neuropeptides in the sea anemone Nematostella unravel recruitment from the nervous system to venom
2020Co-Authors: Maria Y. Sachkova, Adam M Reitzel, Morani Landau, Joachim M. Surm, Jason Macrander, Shir A. Singer, Yehu MoranAbstract:Abstract The sea anemone Nematostella vectensis (Anthozoa, Cnidaria) is a powerful model system for characterizing the evolution of genes functioning in venom and nervous systems. Despite being an example for evolutionary novelty, the evolutionary origin of most toxins remains unknown. Here we report the first bona fide case of protein recruitment from the cnidarian nervous to venom system. The ShK-like1 peptide has ShKT cysteine motif, is lethal for fish larvae and packaged into nematocysts, the cnidarian venom-producing stinging capsules. Thus, ShK-like1 is a toxic venom component. Its paralog, ShK-like2, is a neuropeptide localized to neurons and is involved in development. Interestingly, both peptides exhibit similarities in their functional activities: both of them provoke contraction in Nematostella polyps and are toxic to fish. Because ShK-like2 but not ShK-like1 is conserved throughout sea anemone phylogeny, we conclude that the two paralogs originated due to a Nematostella-specific duplication of a ShK-like2 ancestor, a neuropeptide-encoding gene, followed by diversification and partial functional specialization. Strikingly, ShK-like2 is represented by two gene isoforms controlled by alternative promoters conferring regulatory flexibility throughout development. Additionally, we characterized the expression patterns of four other peptides with structural similarities to studied venom components, and revealed their unexpected neuronal localization. Thus, we employed genomics, transcriptomics and functional approaches to reveal one new venom component, five neuropeptides with two different cysteine motifs and an evolutionary pathway from nervous to venom system in Cnidaria.
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Dataset of Nematostella vectensis Hsp70 isoform interactomes upon heat shock
Data in brief, 2019Co-Authors: Laura E. Knighton, Adam M Reitzel, Nitika, Donald Wolfgeher, Andrew W. TrumanAbstract:Abstract Nematostella vectensis is an estuarine sea anemone that has emerged as a model species to characterize molecular responses to physiological stressors due to its exposure to diverse, extreme abiotic conditions. In marine cnidarians, Hsp70 proteins can be effective biomarkers to determine mechanisms of physiological acclimation and evolutionary adaptations to environmental stress: a pressing issue as concerns about climate change grow. Here we show the results of affinity purification mass spectrometry of three Nematostella vectensis Hsp70 isoforms, NvHsp70A, B and D when expressed in untreated and heat shocked yeast cells lacking their native Hsp70s. We identified a total of 1031 interactors for the three NvHsp70 isoforms, 549 or which were shared. NvHsp70 isoform interactions altered substantially under heat stress with 17% of NvHsp70A, 51% of NvHsp70B and 20% of NvHsp70D interactions increasing after exposure to 39 °C for 2 hours. For further interpretation of the data presented in this article, please see the research article “Dynamic remodeling of the interactomes of Nematostella vectensis Hsp70 isoforms under heat shock”.
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The Birth and Death of Toxins with Distinct Functions: A Case Study in the Sea Anemone Nematostella.
Molecular biology and evolution, 2019Co-Authors: Maria Y. Sachkova, Adam M Reitzel, Jason Macrander, Shir A. Singer, Steve Peigneur, Jan Tytgat, Yehu MoranAbstract:The cnidarian Nematostella vectensis has become an established lab model, providing unique opportunities for venom evolution research. The Nematostella venom system is multimodal: involving both nematocytes and ectodermal gland cells, which produce a toxin mixture whose composition changes throughout the life cycle. Additionally, their modes of interaction with predators and prey vary between eggs, larvae, and adults, which is likely shaped by the dynamics of the venom system. Nv1 is a major component of adult venom, with activity against arthropods (through specific inhibition of sodium channel inactivation) and fish. Nv1 is encoded by a cluster of at least 12 nearly identical genes that were proposed to be undergoing concerted evolution. Surprisingly, we found that Nematostella venom includes several Nv1 paralogs escaping a pattern of general concerted evolution, despite belonging to the Nv1-like family. Here, we show two of these new toxins, Nv4 and Nv5, are lethal for zebrafish larvae but harmless to arthropods, unlike Nv1. Furthermore, unlike Nv1, the newly identified toxins are expressed in early life stages. Using transgenesis and immunostaining, we demonstrate that Nv4 and Nv5 are localized to ectodermal gland cells in larvae. The evolution of Nv4 and Nv5 can be described either as neofunctionalization or as subfunctionalization. Additionally, the Nv1-like family includes several pseudogenes being an example of nonfunctionalization and venom evolution through birth-and-death mechanism. Our findings reveal the evolutionary history for a toxin radiation and point toward the ecological function of the novel toxins constituting a complex cnidarian venom.
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Ultraviolet radiation significantly enhances the molecular response to dispersant and sweet crude oil exposure in Nematostella vectensis.
Marine environmental research, 2018Co-Authors: Ann M Tarrant, Adam M Reitzel, Samantha L. Payton, Danielle T. Porter, Matthew J. JennyAbstract:Estuarine organisms are subjected to combinations of anthropogenic and natural stressors, which together can reduce an organisms' ability to respond to either stress or can potentiate or synergize the cellular impacts for individual stressors. Nematostella vectensis (starlet sea anemone) is a useful model for investigating novel and evolutionarily conserved cellular and molecular responses to environmental stress. Using RNA-seq, we assessed global changes in gene expression in Nematostella in response to dispersant and/or sweet crude oil exposure alone or combined with ultraviolet radiation (UV). A total of 110 transcripts were differentially expressed by dispersant and/or crude oil exposure, primarily dominated by the down-regulation of 74 unique transcripts in the dispersant treatment. In contrast, UV exposure alone or combined with dispersant and/or oil resulted in the differential expression of 1133 transcripts, of which 436 were shared between all four treatment combinations. Most significant was the differential expression of 531 transcripts unique to one or more of the combined UV/chemical exposures. Main categories of genes affected by one or more of the treatments included enzymes involved in xenobiotic metabolism and transport, DNA repair enzymes, and general stress response genes conserved among vertebrates and invertebrates. However, the most interesting observation was the induction of several transcripts indicating de novo synthesis of mycosporine-like amino acids and other novel cellular antioxidants. Together, our data suggest that the toxicity of oil and/or dispersant and the complexity of the molecular response are significantly enhanced by UV exposure, which may co-occur for shallow water species like Nematostella.
