1. Chlorella pyrenoidosa monoculture water enhanced innate immune responses during short-term rearing of juvenile hybrid groupers (Epinephelus lanceolatus × E. fuscoguttatus)
- Author
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Wen Hui Zhang, Cher Chien Lau, Yeong Yik Sung, WenLi Zhou, Zhi Fei Jiang, Jin Wei Gao, ShuaiJun Chen, and Wen Jye Mok
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Microalgae ,Grouper, aquaculture ,Vibriosis ,Green water ,Microbiology ,QR1-502 ,Veterinary medicine ,SF600-1100 - Abstract
Microalgae Chlorella is widely used as immune-enhancer in aquaculture. To investigate the immunoregulatory mechanisms induced by Chlorella pyrenoidosa, the short-term (15 days) and long-term (60 days) immunostimulatory effects of C. pyrenoidosa on hybrid groupers (E. lanceolatus × E. fuscoguttatus) were examined, revealing that juveniles reared in Chlorella monoculture rearing water (CMW) display better survival upon pathogenic Vibrio harveyii challenge than those otherwise. The findings showed reduced free radical activity and higher antioxidant capacity in fish reared short-term and long-term in CMW. The innate immunity was robustly enhanced in short-term CMW rearing, with more mucus cells covering the gill secondary lamellae and the formation of more melano-macrophage centers (MMCs) in the spleen. CMW mitigated organ damage in V. harveyi challenged fish in both short- and long-term trials, but a higher survival was only observed in fish reared short-term in CMW. Transcriptomic analysis revealed that short-term rearing in CMW regulated the expression of innate immune (IRF4, IL-11, IL12RB2, CK3), anti-inflammatory (SELE, PTGIS, HMOX), apoptosis-inhibitory (NR4A1, NR4A3, CTRP3, BCL3), and proteolytic (UBB, HSP70, HSP90, KDM6B, SCARB2) genes. Elevated oxidative phosphorylation-related gene expressions were stimulated, possibly due to the high metabolic commitment of immune system regulation. The findings extend the understanding and provide valuable insights on the immuno-enhancing properties of CMW. The application of CMW would potentially improve marine larviculture performance.
- Published
- 2024
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