Genome-wide identification of heat shock proteins in harpacticoid, cyclopoid, and calanoid copepods: Potential application in marine ecotoxicology

Highlights: • Hsp families in copepods show well-conserved domains. • Genus-specific Hsp divergence was observed in four copepods. • The highest expansion of Hsp40 gene families was observed. • Basal level expression of Hsps in four copepods reveals constitutive expression pattern of Hsp70s. • Genome-widely identified Hsps will be useful in both ecotoxicology and aquatic biology. Constant evolution of omics-technologies has provided access to identification of various important gene families. Recently, genome assemblies on widely used ecotoxicological model species, including rotifers and copepods have been completed and representative detoxification-related gene families have been discovered for biomarker genes. However, despite ubiquitous presence of stress-response proteins, limited information on full genome-wide report on heat shock proteins (Hsps) is available. Various studies have demonstrated multiple cellular functions of Hsps in living organisms as an important biomarker in response to abiotic and biotic stressors, however, full genome-wide identification of Hsps, particularly in aquatic invertebrates, has not been reported. This is the first study to report the entire Hsps and basal gene expression levels in three regional-specific copepods: Tigriopus japonicus and kingsejongensis, Paracyclopina nana, and Eurytemora affnis, and how each Hsp family gene is regulated at a basal level.