image: Fig. Lipidomic and Proteomic Analysis of MHS Liver Tissues Revealing Adaptation Mechanisms to the Hadal Zone. A: Morphological Diagram of the hadal snailfish. B: Sampling locations for the hadal snailfish. C: The left panel displays a heatmap of the percentage composition of 36 lipid subclasses across five deep-sea fish species; The right panel shows the lipid types that significantly vary in NHS compared to other deep-sea fish species. Graph depicting the percentage distribution of different lipid types within the total fat content. D: Total Lipid Content in Liver Tissues of Various Deep-Sea Fish Species. E. Lipid Saturation Analysis in Liver Tissues of Various Deep-Sea Fish Species. F: Top 30 Proteins Expressed in MHS Liver Tissues. G: The top panel displays the triacylglycerol to sterol ratio in liver tissues from five deep-sea fish species, where 'TAG' includes TAG and TAG-O, and 'ST' consists of Cholesterol + CE. The bottom panel shows the ratio of PE to PC, with 'PE' including PE and PEO-, and 'PC' including PC and PCO-; Each species is represented by three biological replicates. H: The Process of Ferroptosis; High expression of TF content in MHS liver.
Credit: Han Xu
The Mariana Trench snailfish (Pseudoliparis swirei) is considered the deepest-living fish species, inhabiting depths exceeding 8,000 meters. This extreme environment presents survival challenges, including high hydrostatic pressure, low temperatures and scarce food resources.
Against this backdrop, members of Professor Hunping He's team from the Institute of Deep-Sea Science and Engineering and the Institute of Hydrobiology at the Chinese Academy of Sciences conducted an in-depth analysis of the lipidomic and proteomic profiles of the snailfish’s enlarged liver tissue, uncovering its unique survival strategies.
“We found that the hadal snailfish exhibits unique adaptations to extreme deep-sea conditions, including specialized lipid and protein metabolism,” shares Han Xu, lead author of the study published in the KeAi journal Water Biology and Security. “These metabolic adjustments allow it to efficiently store energy, optimize energy utilization and maintain membrane fluidity by adjusting lipid types and ratios. Additionally, it possesses a robust mechanism to prevent lipid peroxidation.”
The team found that the hadal snailfish increases lipid reserves in its liver, including cholesterol esters and triacylglycerols, to withstand prolonged periods of food scarcity.
“It also elevates levels of coenzyme Q (CoQ) and ATPase, which enhance energy production efficiency,” says Xu. “Moreover, the proportion of unsaturated fatty acids in its liver is significantly increased, while cholesterol and phosphatidylethanolamine (PE) levels are reduced to maintain membrane fluidity under high-pressure conditions.”
Notable antioxidant adaptations, such as increasing the ratio of monounsaturated fatty acids and enhancing levels of antioxidant proteins like transferrin and heat shock proteins (HSPs), which help reduce the risk of lipid peroxidation, were also noted.
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Contact the author: Han Xu, Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, xuhan@idsse.ac.cn
The publisher KeAi was established by Elsevier and China Science Publishing & Media Ltd to unfold quality research globally. In 2013, our focus shifted to open access publishing. We now proudly publish more than 190 world-class, open access, English language journals, spanning all scientific disciplines. Many of these are titles we publish in partnership with prestigious societies and academic institutions, such as the National Natural Science Foundation of China (NSFC).
Journal
Water Biology and Security
Method of Research
Experimental study
Subject of Research
Animals
Article Title
Lipidome and proteome analyses provide insights into Mariana Trench Snailfish (Pseudoliparis swirei) adaptation to the hadal zone
COI Statement
The authors declare no competing interests.