This is an early access version, the complete PDF, HTML, and XML versions will be available soon.
Heat Acclimation Enhances Brain Resilience to Acute Thermal Stress in Clarias fuscus by Modulating Cell Adhesion, Anti-Apoptotic Pathways, and Intracellular Degradation Mechanisms
by
, ,
Yingyi Guan
1,†
,
Cunyu Duan
1,†,
Xinyu Xie
1,
Zhuoying Luo
1,
Dayan Zhou
2,
Yulei Zhang
1,
Guangli Li
1,
Yu Liao
2,* and
Changxu Tian
1,*
1
Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Guangdong Provincial Engineering Laboratory for Mariculture Organism Breeding, Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China
2
Guangxi Introduction and Breeding Center of Aquaculture, Nanning 530001, China
*
Authors to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Animals 2025, 15(9), 1220; https://doi.org/10.3390/ani15091220
Submission received: 25 March 2025
/
Revised: 20 April 2025
/
Accepted: 23 April 2025
/
Published: 25 April 2025
(This article belongs to the Section Animal Welfare)
Simple Summary
Climate change has resulted in rising water temperatures, threatening the survival of fish species, such as the Hong Kong catfish. This study aimed to understand how these fish adapt their brains to heat stress. Our findings indicate that fish acclimated to higher temperatures exhibit better brain protection under sudden heat stress. Specifically, their brains rapidly activate genes involved in preventing cell death, repairing tissue, and clearing damaged components. These insights could inform the breeding of more heat-tolerant fish, ensuring sustainable aquaculture practices as global temperatures continue to rise.
Abstract
Global climate change presents a significant challenge to aquatic ecosystems, with ectothermic fish being particularly sensitive to temperature fluctuations. The brain plays a crucial role in perceiving, regulating, and adapting to thermal changes, and its response to heat stress is crucial for survival. However, the molecular mechanisms underlying heat stress and acclimation in fish brains remain poorly understood. This study aimed to investigate the adaptive mechanisms of Hong Kong catfish (Clarias fuscus) brains under heat acclimation and acute heat stress using transcriptome analysis. Fish were divided into two groups: a normal temperature group (NT, 26 °C for 90 days) and a heat-acclimated group (HT, 34 °C for 90 days), followed by acute heat stress (34 °C for 72 h) and recovery (26 °C for 72 h). Heat acclimation improved C. fuscus tolerance to acute heat stress, with faster gene responses and stronger neuroprotection. Key pathways enriched included cell adhesion and ECM-receptor interactions during recovery. Apoptosis regulation was balanced, with the HT group upregulating anti-apoptotic genes to mitigate neuronal cell death. Additionally, the lysosome–phagosome pathway was activated during recovery, facilitating the transport of lysosomal enzymes and the clearance of damaged cellular components, aiding neuronal repair. Ribosome biogenesis was suppressed under heat stress to conserve energy, but this suppression was less pronounced in the HT group. In summary, heat acclimation enhances neural protection in C. fuscus brains by promoting neuronal repair, suppressing apoptosis, and activating lysosomal pathways, thereby improving tolerance to acute heat stress. These findings offer a molecular basis for breeding heat-tolerant fish species in aquaculture, and deepen our understanding of thermal adaptation in aquatic animals amid global climate change.
Keywords:
catfish; heat acclimation; adaptive regulation; brain transcriptome
