Multi-organ transcriptomics provide insights into growth regulation in the Dongtingking crucian carp (Carassius auratus indigentiaus).

To investigate the key regulatory genes and pathways related to growth traits in the Dongtingking crucian carp (Carassius auratus indigentiaus), the transcriptomes of brain, intestine, and muscle tissues were sequenced at early juvenile stage using RNA-Seq from two groups with extreme growth rates (fast-growing and slow-growing). A total of 65, 184, and 130 differentially expressed genes (DEGs) were detected in the brain, intestine, and muscle, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis highlighted that the PPAR signaling pathway, Insulin/PI3K/Akt/mTOR/FoxO/AMPK pathway, and Protein digestion and absorption pathways are crucial for growth in this species. Based on the transcriptome data, 32 key DEGs were identified, mainly participating in processes such as cell proliferation and differentiation, growth, development, and metabolism. Prominent examples are cyclic AMP-responsive element-binding protein 5 (creb5b), forkhead box protein O1-A (foxo1a), transcription factor AP-1-like (jun), lipoprotein lipase-like (lpl), angiopoietin-like 4 (angptl4), and egl nine homolog 3-like (egln3). This study enhances the understanding of the genetic factors and regulatory mechanisms responsible for variations in growth rates and provides a valuable basis for further studies on the regulatory mechanisms of growth in C. auratus indigentiaus.