Project description:Beginning in 2013, sea stars throughout the Eastern North Pacific were decimated by wasting disease, also known as ‘asteroid idiopathic wasting syndrome’ (AIWS) due to its elusive etiology. The geographic extent and taxonomic scale of AIWS meant events leading up to the outbreak were heterogeneous, multifaceted, and oftentimes unobserved; progression from morbidity to death was rapid, leaving few tell-tale symptoms. Here we take a forensic genomic approach to discover candidate genes that may help explain sea star wasting syndrome. We report the first genome and annotation for P. ochraceus, along with differential gene expression (DGE) analyses in four size classes, three tissue types, and in symptomatic and asymptomatic individuals. We integrate nucleotide polymorphisms associated with survivors of the wasting disease outbreak, DGE associated with temperature treatments in P. ochraceus, and DGE associated with wasting in another asteroid Pycnopodia helianthoides. In P. ochraceus, we find DGE across all tissues, among size classes, and between asymptomatic and symptomatic individuals; the strongest wasting-associated DGE signal is in pyloric caecum. We also find previously identified outlier loci co-occur with differentially expressed genes. In cross-species comparisons of symptomatic and asymptomatic individuals, consistent responses distinguish genes associated with invertebrate innate immunity and chemical defense, consistent with context-dependent stress responses, defensive apoptosis, and tissue degradation. Our analyses thus highlight genomic constituents that may link suspected environmental drivers (elevated temperature) with intrinsic differences among individuals (age/size, alleles associated with susceptibility) that elicit organismal responses (e.g. coelomocyte proliferation) and manifest as sea star wasting mass mortality.
2020-02-19 | GSE144422 | GEO
Project description:16s microbial sequecning of wild Pycnopodia helianthoides experiencnig outbreak of Sea Star Wasting Disease
Project description:We identified cis-regulatory elements based on their dynamic chromatin accessibility during the gastrula-larva stages of sea urchin and sea star and studied their evolution in these echinoderm species
2021-10-24 | GSE186363 | GEO
Project description:16s amplicon sequencing V3-V4 region from Pisaster ochraceus samples with and without Sea Star Wasting Disease
Project description:Purpose: The Tbrain transcription factor has demonstrated an evolved preference for low-affinity, secondary site binding motifs between the sea star and sea urchin orthologs. We sought to identify targets of sea urchin and sea star orthologs of Tbr. Because less is known about the function of Tbr during sea star development, we used RNA-seq in conjuction with ChIP-seq studies (GEO:xxxx) to determine the targets of sea star Tbr in early development. Methods: Sea star (Patiria miniata) embryos were injected with translation-blocking morpholino antisense oligonucleotides to knock-down PmTbr expression, as described previously. Control morpholinos were injected into sibling embryos. Embryos were allowed to develop until hatching (30-36 hpf) at which point injected embryos were collected and RNA was extracted. RNA-seq libraries were prepared, sequenced, and analyzed using standard protocols. Results: There are 2,562 genes that are significantly differentially expressed relative to control morpholino inected embryos (FDR < 0.05). There are roughly equivalent numbers of genes down-regulated (1,041) and up-regulated (1,521) by Pm-tbr knockdown, suggesting that PmTbr may act as both a transcriptional activator and repressor. 1,165 differentially expressed genes are located within 75 kb of a PmTbr binding site determined using ChIP-seq, and this set is used as a basis for comparison between sea star and sea urchin binding sites. Conclusions: 1,165 targets of the PmTbr transcription factor were identified based on differential expression following knockdown and the presence of transcription factor binding sites proximal to differentially expressed genes. There are an equal number of up- and down-regulated targets, suggesting Tbr may function as a transcriptional activator and repressor, depending on context and target gene. There was no clear association of motif utilization with either the direction of differential expression or ontological category of the target gene. There are only a small fraction of target genes (approximately 10%) that are in common between the sea star and sea urchin sets.
2016-12-01 | GSE89863 | GEO
Project description:Comparison of DNA extraction methods for examining asteroid dermal microbiomes in the context of sea star wasting disease
Project description:The affinity of the echinoderm pentaradial body plan with that of the ancestral bilateral symmetry remains one of the biggest zoological puzzle. Here, we revisited this classical zoological problem using RNA tomography and HCR in situ hybridization in the sea star Patiria miniata.