Proteome analysis and thermal-tolerant protein marker screening in the skin mucus of large yellow croaker Larimichthys crocea

Fish skin mucus serves as the first line of defense against pathogens and external stressors. To screen thermal tolerant protein marker in the skin mucus of large yellow croaker Larimichthys crocea, this study conducted proteome analysis on skin mucus between thermal-tolerant and thermal-sensitive groups of large yellow croaker. A total of 396 differentially expressed proteins (DEPs) were identified, among which 215 proteins were upregulated and 181 proteins were downregulated. Ten selected random DEPs were validated using a parallel reaction monitoring (PRM) assay, and the results showed that the proteome analysis results were reliable (r = 0.805, P < 0.01). The bioinformatics analysis indicated that the proteins with significant changes were involved in immune defense, energy metabolism and heat shock, in which lily-type lectin, plasma protease C1 inhibitor, thrombospondin-1, calreticulin, pyruvate kinase and heat shock protein 70 played important roles in the course of adaption to high temperature and can be used as candidate thermal-tolerant protein markers in large yellow croaker. The results of this study provide a reference for constructing a noninvasive detection technology for assisting in the breeding of thermal-tolerant strains of large yellow croaker in the future.