Multi-organ transcriptomics analysis of a slowly growing fish rock carp (Procypris rabaudi) reveals insights into mechanism of growth rate regulation

To explore the patterns of differentially expressed genes (DEGs) associated with different growth rates in rock carp (Procypris rabaudi), transcriptome sequencing was performed on the muscle, liver, and brain tissues of rock carp. Subsequently, bioinformatics analysis was conducted, and 2129, 1380, and 415 DEGs were identified in the muscle, liver, and brain tissues, respectively. GO enrichment and KEGG pathway analysis revealed that genes related to appetite regulation, protein degradation and digestion, lipid transport and metabolisms, and glycolysis/gluconeogenesis were upregulated in individuals with slower growth rates. Differential expression analysis identified 21 genes associated with feeding and metabolism across three tissues, including mc4r, npy, and npry in brain tissue; fatp, fabp, pparα, and apo in liver tissue; and prss, ctrl, and cela in muscle tissue. All these genes were upregulated in the slow-growing fish. Furthermore, weighted gene co-expression network analyses, including three modules (yellow, turquoise, and brown), significantly associated with growth. A network map that included these three modules enabled the identification of a series of hub genes, including rp13a, ube2o, h6pd, etc. These genes may be key candidate genes regulating the growth of rock carp. This study contributes to a deeper understanding of the growth control mechanism in rock carp and offers a scientific basis for efficient breeding and species improvement.