Integrated miRNA-mRNA Atlas Reveals Temperature-Graded Brain Neuroendocrine Adaptation to Cold Stress in Silvery Pomfret (Pampus argenteus).

Temperature stress is a major cause of mortality in aquaculture, yet the molecular mechanisms underlying cold adaptation in commercially important fish such as the silver pomfret (Pampus argenteus) remain poorly understood. In this study, we used integrated miRNA and mRNA transcriptomics to analyze brain tissue responses of silver pomfret under gradient cold exposure conditions (28 °C control, 18 °C moderate, 13 °C extreme). We identified 85 differentially expressed miRNAs (DEmiRs), with 22 altered under moderate cold and 68 altered in extreme cold, demonstrating that miRNA regulatory activity intensifies with decreasing temperature. Combined miRNA target prediction and expression correlation analysis revealed 8 and 247 differentially expressed target genes (DETGs), which formed cold-adaptive regulatory networks with corresponding DEmiRs. Functional analysis showed enrichment of pathways related to circadian rhythm (e.g., PER targeted by miR-429-y and miR-181-z), immunity (e.g., JUN-miR-10545-x cluster), and endocrine function (e.g., NHERF1-miR-181-z). Notably, miR-181-z was identified as a central regulatory hub, interacting with 13.2% nodes in BE network. Our study provides the first comprehensive miRNA-mRNA network resource for cold stress response in silver pomfret, offering valuable molecular biomarkers for breeding cold-resilient strains and enhancing sustainable aquaculture practices.