Environmental and molecular regulation of asexual reproduction in the cnidarian Nematostella vectensis
Ontology highlight
ABSTRACT:
ORGANISM(S): Nematostella vectensis
PROVIDER: GSE223794 | GEO | 2023/06/21
REPOSITORIES: GEO
Similar Datasets
Project description:Cnidarians exhibit incredible reproductive diversity, with most capable of sexual and asexual reproduction. Here we investigate factors that influence asexual reproduction in the burrowing sea anemone Nematostella vectensis , which can propagate asexually by transverse fission of the body column. By altering culture conditions, we demonstrate that the presence of a burrowing substrate strongly promotes transverse fission. In addition, we show that animal size does not affect fission rates, and that the plane of fission is fixed along the oral-aboral axis of the polyp. Homeobox transcription factors and components of the TGFβ, Notch, and FGF signaling pathways are differentially expressed in polyps undergoing physal pinching suggesting they are important regulators of transverse fission. Gene ontology analyses further suggest that during transverse fission the cell cycle is suppressed and that cell adhesion and patterning mechanisms are downregulated to promote separation of the body column. Finally, we demonstrate that the rate of asexual reproduction is sensitive to population density. Collectively, these experiments provide a foundation for mechanistic studies of asexual reproduction in Nematostella , with implications for understanding the reproductive and regenerative biology of other cnidarian species.
| S-EPMC9900923 | biostudies-literature
Project description:Cnidarians exhibit incredible reproductive diversity, with most capable of sexual and asexual reproduction. Here, we investigate factors that influence asexual reproduction in the burrowing sea anemone Nematostella vectensis, which can propagate asexually by transverse fission of the body column. By altering culture conditions, we demonstrate that the presence of a burrowing substrate strongly promotes transverse fission. In addition, we show that animal size does not affect fission rates, and that the plane of fission is fixed along the oral-aboral axis of the polyp. Homeobox transcription factors and components of the TGFβ, Notch, and FGF signalling pathways are differentially expressed in polyps undergoing physal pinching suggesting they are important regulators of transverse fission. Gene ontology analyses further suggest that during transverse fission the cell cycle is suppressed, and that cell adhesion and patterning mechanisms are downregulated to promote separation of the body column. Finally, we demonstrate that the rate of asexual reproduction is sensitive to population density. Collectively, these experiments provide a foundation for mechanistic studies of asexual reproduction in Nematostella, with implications for understanding the reproductive and regenerative biology of other cnidarian species.
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Project description:Using forward transcriptomics, we show that beta-catenin/Tcf signaling and BMP2/4 signaling provide differential inputs into the cnidarian endomesodermal gene regulatory network (GRN) at the onset of gastrulation (24 h postfertilization) in N. vectensis. Surprisingly, beta-catenin/Tcf signaling and BMP2/4 signaling regulate a subset of common downstream target genes in the GRN in opposite ways, leading to the spatial and temporal differentiation of fields of cells in the developing embryo. Thus, we show that regulatory interactions between beta-catenin/Tcf signaling and BMP2/4 signaling are required for the specification and determination of different embryonic regions and the patterning of the oral?aboral axis in Nematostella.
2017-07-19 | GSE101604 | GEO
Project description:The ability to learn and form memories allows animals to adapt their behavior based on previous experiences. Associative learning, the process through which organisms learn about the relationship between two distinct events, has been extensively studied in various animal taxa. However, the existence of associative learning, prior to the emergence of centralized nervous systems in bilaterian animals, remains unclear. Cnidarians such as sea anemones or jellyfish possess a nerve net, which lacks centralization. As the sister group to bilaterians, they are particularly well suited for studying the evolution of nervous system functions. Here, we probe the capacity of the starlet sea anemone Nematostella vectensis to form associative memories by using a classical conditioning approach. We developed a protocol combining light as the conditioned stimulus with an electric shock as the aversive unconditioned stimulus. After repetitive training, animals exhibited a conditioned response to light alone-indicating that they learned the association. In contrast, all control conditions did not form associative memories. Besides shedding light on an aspect of cnidarian behavior, these results root associative learning before the emergence of NS centralization in the metazoan lineage and raise fundamental questions about the origin and evolution of cognition in brainless animals.
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Project description:Notch signaling is among the oldest of known Metazoan signaling pathways and is used in a multitude of developmental contexts to effect cellular differentiation, specification and the maintenance of stem cell state. Here we report the isolation and expression of the canonical Notch signaling pathway in the early branching metazoan Nematostella vectensis (Anthozoa, Cnidaria) during embryonic and larval development. We have used pharmacological treatment, morpholino knockdown, and dominant negative misexpression experiments to demonstrate that Notch signaling acts to mediate cnidogenesis, the development of cnidarian-specific neural effecter cells. Notch signaling often results in the transcriptional activation of NvHes genes, a conserved family of bHLH transcription factors. A loss of Notch signaling through use of pharmacological inhibition or knock-down of the Notch effecter gene Suppressor of Hairless Su(H) similarly results in a loss of cnidocyte cell fate. We also provide evidence that Notch signaling is responsible for certain aspects of neurogenesis in developing N. vectensis planula in which disruption of Notch cleavage via the pharmacological agent DAPT results in increased expression of neural marker genes in vivo. This data suggests that Notch signaling acting on components of the developing nervous system is an ancient role of this pathway. The shared requirement of Notch signaling for the development of both cnidocytes and neurons further supports the hypothesis that cnidocytes and neurons share common origins as multifunctional sensory-effecter cells.
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Project description:In animals, circadian rhythms are driven by oscillations in transcription, translation, and proteasomal degradation of highly conserved genes, resulting in diel cycles in the expression of numerous clock-regulated genes. Transcription is largely regulated through the binding of transcription factors to cis-regulatory elements within accessible regions of the chromatin. Chromatin remodeling is linked to circadian regulation in mammals, but it is unknown whether cycles in chromatin accessibility are a general feature of clock-regulated genes throughout evolution. To assess this, we applied an ATAC-seq approach using Nematostella vectensis, grown under two separate light regimes (light:dark (LD) and constant darkness (DD)). Based on previously identified N. vectensis circadian genes, our results show the coupling of chromatin accessibility and circadian transcription rhythmicity under LD conditions. Out of 180 known circadian genes, we were able to list 139 gene promoters that were highly accessible compared to common promoters. Furthermore, under LD conditions, we identified 259 active enhancers as opposed to 333 active enhancers under DD conditions, with 171 enhancers shared between the two treatments. The development of a highly reproducible ATAC-seq protocol integrated with published RNA-seq and ChIP-seq databases revealed the enrichment of transcription factor binding sites (such as C/EBP, homeobox, and MYB), which have not been previously associated with circadian signaling in cnidarians. These results provide new insight into the regulation of cnidarian circadian machinery. Broadly speaking, this supports the notion that the association between chromatin remodeling and circadian regulation arose early in animal evolution as reflected in this non-bilaterian lineage.
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Project description:The role of viruses in forming a stable holobiont has been the subject of extensive research in recent years. However, many emerging model organisms still lack any data on the composition of the associated viral communities. Here, we re-analyzed seven publicly available transcriptome datasets of the starlet sea anemone Nematostella vectensis, the most commonly used anthozoan lab model, and searched for viral sequences. We applied a straightforward, yet powerful approach of de novo assembly followed by homology-based virus identification and a multi-step, thorough taxonomic validation. The comparison of different lab populations of N. vectensis revealed the existence of the core virome composed of 21 viral sequences, present in all adult datasets. Unexpectedly, we observed an almost complete lack of viruses in the samples from the early developmental stages, which together with the identification of the viruses shared with the major source of the food in the lab, the brine shrimp Artemia salina, shed new light on the course of viral species acquisition in N. vectensis. Our study provides an initial, yet comprehensive insight into N. vectensis virome and sets the first foundation for the functional studies of viruses and antiviral systems in this lab model cnidarian.
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Project description:The spatial transcriptome data has allowed us to explore the differential gene expression among the oral-aboral domains and provided new insights into the apical organ signalling pathways for future mechanistic studies and genes associated with oral/aboral differentiation. This resource identifies numerous candidates for elucidating the functional role of the apical organ and to address the evolution of the metazoan larval nervous system.
2021-10-01 | GSE159166 | GEO
Project description:Environmental and molecular regulation of asexual reproduction in the cnidarian Nematostella vectensis
| PRJNA928393 | ENA
Project description:An ancient evolutionary innovation of a novel cell type, the stinging cell (cnidocyte), appeared >600 million years ago in the phylum Cnidaria (sea anemones, corals, hydroids, and jellyfish). A complex bursting nano-injector of venom, the cnidocyst, is embedded in cnidocytes and enables cnidarians to paralyze their prey and predators, contributing to this phylum's evolutionary success. In this work, we show that post-transcriptional regulation by a pan-cnidarian microRNA, miR-2022, is essential for biogenesis of these cells in the sea anemone Nematostella vectensis. By manipulation of miR-2022 levels in a transgenic reporter line of cnidocytes, followed by transcriptomics, single-cell data analysis, prey paralysis assays, and cell sorting of transgenic cnidocytes, we reveal that miR-2022 enables cnidocyte biogenesis in Nematostella, while exhibiting a conserved expression domain with its targets in cnidocytes of other cnidarian species. Thus, here we revealed a functional basis to the conservation of one of nature's most ancient microRNAs.
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