Comparative Transcriptomics Reveals Potential Regulatory Mechanisms Underlying Changes in Antioxidant, Anti-Inflammatory, and Other Immune Functions Induced by Bellamya purificata Polysaccharides in Cherax quadricarinatus

This study investigated the potential effects of Bellamya purificata polysaccharide (BPP) supplementation in feed on Cherax quadricarinatus, aiming to elucidate its impact on immune function and the underlying regulatory mechanisms. A 60-day feeding trial was conducted to evaluate the effects of varying dietary BPP concentrations (0‰, 2‰, 4‰, 6‰, and 8‰) on growth performance, histopathology, immune function, and transcriptomic profiles of C. quadricarinatus. Dietary BPP significantly increased the final body length and body weight of C. quadricarinatus. Furthermore, BPP inclusion improved the histological damage of hepatopancreatic tissues, alleviated physiological stress, and enhanced antioxidant capacity, antibacterial activity, and anti-inflammatory function, as evidenced by alterations in relevant enzyme activities and gene expression levels. Transcriptomic analysis revealed 957 differentially expressed genes (DEGs), which were predominantly enriched in GO terms and KEGG pathways associated with BPP-mediated immune regulation, such as the PPAR signaling pathway, peroxisome, steroid hormone biosynthesis, and lysosome. In addition, 14 candidate genes were identified, including Acox3, ACOX1, SCP2, and PPT1. Integrated analysis of GO, KEGG, and Short Time-Series Expression Miner (STEM) data supported the development of a mechanistic model illustrating how C. quadricarinatus modulates immune function in response to BPP supplementation. RT-qPCR validation confirmed the accuracy and reliability of the high-throughput sequencing results. Collectively, these findings highlight the potential of BPP as a functional feed additive in aquaculture and provide novel insights into disease prevention strategies for the C. quadricarinatus farming industry.