Project description:Using hMeDIP-seq we validated the single-base resolution hydroxymethylomes (ACE-seq) of sea urchin, lancelet and zebrafish embryos.
Project description:Transcriptional profiling of purple sea urchin (Strongylocentrotus purpuratus) larvae cultured under three different seawater CO2 concentrations 400, 800, 1200 µatm. The goal was to determine the effects of CO2, an important climate change variable, on global gene expression
Project description:Classical embryological studies revealed that during mid-embryogenesis vertebrates show similar morphologies. This âphylotypic 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 âzootypicâ 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. 165 single embryo samples.
Project description:Transcriptional profiling of purple sea urchin (Strongylocentrotus purpuratus) larvae cultured under three different seawater CO2 concentrations 400, 800, 1200 M-BM-5atm. The goal was to determine the effects of CO2, an important climate change variable, on global gene expression Larvae were cultured under three different seawater CO2 concentrations 400, 800, 1200 M-BM-5atm, each with four replicate cultures, and sampled at two developmental stages (gastrula and pluteus)
Project description:The eukaryotic nucleosome is the fundamental subunit of chromatin and plays functional roles in DNA templated processes including replication and transcription. In eukaryotic promoters, nucleosome organization is generally thought to be highly structured, with nucleosomes occupying canonical positions flanking the transcription start site (TSS), thereby regulating access of the transcriptional machinery to the underlying DNA. We sought to determine whether this canonical distribution is present in the purple sea urchin, Strongylocentrotus purpuratus, an important developmental model organism. We used titrations of micrococcal nuclease to produce high throughput maps of nucleosome distribution, sensitivity to digestion, and subnucleosomal footprints from female urchin gonad tissue. Unlike yeast, flies, zebrafish, maize, or humans, urchins lack a nucleosome depleted region over TSSs. Urchin promoters are dominated by strongly positioned and highly occupied +1 and +2 nucleosomes which are most prominent in highly expressed genes. Additionally, urchin promoters exhibit distinct patterns of sensitivity to nuclease digestion, with heightened sensitivity upstream of the TSS and limited resistance to nuclease digestion. Discretely positioned sensitive nucleosomes were enriched in promoters of highly expressed genes, suggesting a relationship between nucleosome sensitivity and transcriptional regulation. Moreover, urchin promoters were enriched for small fragment-protected footprints associated with known regulatory motifs. Collectively, we present a comprehensive overview of the unique interplay between nucleosome positioning, chromatin sensitivity, cis-regulatory interactions, and gene expression in sea urchins. Our study not only provides a reproducible methodology applicable to other organisms, but also advances our understanding of functional chromatin organization and gene regulation in urchins.
Project description:This is the inaugural dataset for the new GRIP-seq method to map cis-regulatory regions genome-wide. This dataset is for the purple sea urchin embryo, S. purpuratus, at 24 hours post fertilization. There are two experimental samples using an anti-Pol(II) antibody to pull down regulatory region-promoter complexes and one control using IgG alone. Full details of the GRIP-seq methodology are available in the linked manuscript. Bam index (bai) files and tiled data (tdf) files are also available at http://www.ebi.ac.uk/arrayexpress/experiments/E-MTAB-3607/files/
