Project description:In mammals, the cGAS-cGAMP-STING pathway is crucial for sensing viral infection and initiating an anti-viral type I interferon response. cGAS and STING are highly conserved genes that originated in bacteria and are present in most animals. By contrast, interferons only emerged in vertebrates; thus, the function of STING in invertebrates is unclear. Here, we use the STING ligand 2'3'-cGAMP to activate immune responses in a model cnidarian invertebrate, the starlet sea anemone Nematostella vectensis. Using RNA-Seq, we found that 2'3'-cGAMP induces robust transcription of both anti-viral and anti-bacterial genes, including the conserved transcription factor NF-κB. Knockdown experiments identified a role for NF-κB in specifically inducing anti-bacterial genes downstream of 2'3'-cGAMP, and some of these genes were also found to be induced during Pseudomonas aeruginosa infection. Furthermore, we characterized the protein product of one of the putative anti-bacterial genes, the N. vectensis homolog of Dae4, and found that it has conserved anti-bacterial activity. This work describes an unexpected role of a cGAMP sensing pathway in anti-bacterial immunity and suggests that a broad transcriptional response is an evolutionarily ancestral output of 2'3'-cGAMP signaling in animals.
Project description:MicroRNAs of bilaterian animals undergo posttranscriptional modifications such as methylation, tailing and trimming that regulate miRNA stability and function. To gain insight on the evolution of miRNA posttranscriptional modification, we studied regulation of miRNA stability by methylation in the sea anemone Nematostella vectensis, a representative of Cnidaria, the sister group of Bilateria.
Project description:We assessed genome-wide temporal transcript expression patterns in the sea anemone, Nematostella vectensis, in Great Sippewissett Marsh in Massachusetts, where anemones experienced a natural light cycle with intensity varying from 0-200 lum/ft2, daily temperature fluctuations of ~9C. We measured ‘in situ’ gene expression from recaptured anemones every hour from 0800 to 1700 and identified six time-dependent gene clusters, represented by several genes involved in metabolism, stress, and transcription-translation related functions.
Project description:NvNcol3::mOrange2 is a stable transgenic line that labels cnidocytes(stinging cells) of the sea anemone Nematostella vectensis (Nakanishi et al., Development 2012). Two week old primary polyps were dissociated and the NvNcol3::mOrange2 positive and negative cells were enriched by FACS.
Project description:NvElav1::mOrange is a stable transgenic line that labels a large fraction of the nervous system of the sea anemone Nematostella vectensis (Nakanishi et al., Development 2012). Two week old primary polyps were dissociated and the NvElav1::mOrange positive cells were enriched by FACS.
Project description:The aim of this part of the wider project is to identify neuropeptide precursors, investigate cleavage sites on neuropeptide precursors and predict mature peptides in the sea anemone Nematostella vectensis. This was done to create a synthetic library of N. vectensis neuropeptides which were then used to test neuropeptide receptor candidates for activation by the different peptides.
Project description:Cnidarians, including corals, sea anemones, and jellyfish, possess specialized stinging cells called cnidocytes that function in prey capture and defense. These cells represent a striking evolutionary innovation and include distinct types such as venom injecting nematocytes and mechanically acting spirocytes. While their biomechanics and transcriptional regulation have been studied extensively, little is known about their epigenetic regulation. Here, we combined epigenetic profiling with RNA sequencing in the sea anemone Nematostella vectensis to explore regulatory programs underlying cnidocyte diversity. We identified cell type specific regulatory elements in promoter and enhancer regions and linked them to distinct gene expression programs. This analysis revealed fundamental differences between nematocytes and spirocytes and uncovered a previously unrecognized nematocyte population that expresses the nep3 toxin but lacks most other toxins. These findings highlight the complexity of cnidocyte regulation and suggest greater cellular diversity within this defining cnidarian cell type than previously appreciated.
Project description:Classical embryological studies revealed that during mid-embryogenesis vertebrates show similar morphologies. This “phylotypic stage” has recently received support from transcriptome analyses, which have also detected similar stages in nematodes and arthropods. A conserved stage in these three phyla has led us to ask if all animals pass through a universal definitive stage as a consequence of ancestral constraints on animal development. Previous work has suggested that HOX genes may comprise such a ‘zootypic’ stage, however this hypothetical stage has hitherto resisted systematic analysis. We have examined the embryonic development of ten different animals each of a fundamentally different phylum, including a segmented worm, a flatworm, a roundworm, a water bear, a fruitfly, a sea urchin, a zebrafish, a sea anemone, a sponge, and a comb jelly. For each species, we collected the embryonic transcriptomes at ~100 different developmental stages and analyzed their gene expression profiles. We found dynamic gene expression across all of the species that is structured in a stage like manner. Strikingly, we found that animal embryology contains two dominant modules of zygotic expression in terms of their protein domain composition: one involving proliferation, and a second involving differentiation. The switch between these two modules involves induction of the zootype; which in addition to homeobox containing genes, also involves Wnt and Notch signaling as well as forkhead domain transcription factors. Our results provide a systematic characterization of animal universality and identify the points of embryological constraints and flexibility.
Project description:Classical embryological studies revealed that during mid-embryogenesis vertebrates show similar morphologies. This â??phylotypic stageâ?? has recently received support from transcriptome analyses, which have also detected similar stages in nematodes and arthropods. A conserved stage in these three phyla has led us to ask if all animals pass through a universal definitive stage as a consequence of ancestral constraints on animal development. Previous work has suggested that HOX genes may comprise such a â??zootypicâ?? stage, however this hypothetical stage has hitherto resisted systematic analysis. We have examined the embryonic development of ten different animals each of a fundamentally different phylum, including a segmented worm, a flatworm, a roundworm, a water bear, a fruitfly, a sea urchin, a zebrafish, a sea anemone, a sponge, and a comb jelly. For each species, we collected the embryonic transcriptomes at ~100 different developmental stages and analyzed their gene expression profiles. We found dynamic gene expression across all of the species that is structured in a stage like manner. Strikingly, we found that animal embryology contains two dominant modules of zygotic expression in terms of their protein domain composition: one involving proliferation, and a second involving differentiation. The switch between these two modules involves induction of the zootype; which in addition to homeobox containing genes, also involves Wnt and Notch signaling as well as forkhead domain transcription factors. Our results provide a systematic characterization of animal universality and identify the points of embryological constraints and flexibility. 123 single embryo samples.