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: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:While FGF mediated MEK/ERK signaling is required for apical tuft formation and metamorphosis in the sea anemone Nematostella vectensis (Rentzsch et al, 2008), nothing is known about the role of MEK/ERK signaling in inducing germ layers and cell types during early developmental stages. We therefore performed a genome wide expression array on UO126 (MEK inhibitor) treated blastula stages compared to DMSO treated control embryos and identified genes potentially involved in neurogenesis, germ layer specification and axial patterning.We performed transcriptional profiling of Nematostella vectensis blastula stages (24 hours post fertilisation @ 17C) using a custom made whole genome array (4x72K - A-MEXP-2380). DMSO treated wild-type embryos were compared to U0126 (MEK Inhibitor) treated embryos at the blastula stage.
