Transcriptional landscape of brain adaptation to artificial feed domestication in mandarin fish (Siniperca chuatsi) revealed by weighted gene co-expression network analysis

Abstract

Mandarin fish (Siniperca chuatsi) initially reject dead prey or artificial feed, yet their innate feeding behaviors can be modified through training. However, the changes in gene expression in the brain and the associated molecular mechanisms underlying the acquisition of new feeding behaviors in mandarin fish are not well understood. In this study, two groups of mandarin fish were established: one group that was easily domesticated and transitioned from live prey to artificial diets (QN group), and another group that failed to adapt to artificial diets throughout the domestication process (DN group). The results showed that the QN group had significantly greater body weight and length compared to the DN group. Transcriptome analysis identified 811 differentially expressed genes (DEGs), with 393 genes upregulated and 418 downregulated. Functional enrichment analysis revealed significant enrichment in the steroid biosynthesis pathway. Weighted gene co-expression network analysis (WGCNA) identified brown and turquoise modules strongly correlated with high artificial feed intake, containing 1849 genes. KEGG analysis further indicated that the steroid biosynthesis pathway, especially progesterone synthesis, plays a key role in the dietary adaptation process. RT-qPCR and ELISA validation of transcriptome data confirmed the upregulation of progesterone levels, closely associated with food habit domestication. It was therefore speculated that the mandarin fish's ability to consume artificial diets might be attributed to the upregulation of genes associated with steroid biosynthesis, which in turn promotes progestogen synthesis. This study suggested a link between steroid biosynthesis and dietary domestication in animals, potentially revealing a novel molecular mechanism underlying dietary domestication.