Transcriptomic Responses of Blue Bat Star Patiria pectinifera to Sediment Burial

Sediment burial generated by deep-sea mining is usually lethal to echinoderms, which are ecologically important in marine environments. However, their molecular mechanisms responding to sediment burial are still rarely investigated. In this study, Patiria pectinifera was investigated for sediment burial research to analyze its gene expression variations by using comparative transcriptomes and to probe into shared molecular mechanisms of echinoderms under sediment burial. During sediment burial experiments, dissolved oxygen continuously decreased, which had a significant impact on Patiria pectinifera, which suffered from hypoxic stress. Based on functional annotations of differentially expressed genes (DEGs), its metabolic patterns altered with the upregulated DEGs related to glycolysis and fatty acid degradation and the downregulated ones in the citrate cycle, and its immune responses also varied with the upregulated DEGs of apoptosis and the downregulated ones defending against pathogens. Meanwhile, the peroxisome proliferator-activated receptor signaling pathway and retinoic acid-inducible gene I-like receptor signaling pathway were also upregulated, indicating metabolic and immune changes. Furthermore, combined with functional annotations of twelve echinoderm reference genomes, those DEGs related to lipid metabolism and the immune response were also universally present in the echinoderm genomes. Our study probes into shared molecular mechanisms of echinoderms under sediment burial, which advances our understanding of echinoderms affected by deep-sea mining.