Structure and gene expression changes of the gill and liver in juvenile black porgy (Acanthopagrus schlegelii) under different salinities

Tangjian Zhou; Qian Meng; Ruijian Sun; Dafeng Xu; Fei Zhu; Chaofeng Jia; Shimiao Zhou; Shuyin Chen; Yunxia Yang

doi:10.1016/j.cbd.2024.101228

Structure and gene expression changes of the gill and liver in juvenile black porgy (Acanthopagrus schlegelii) under different salinities

Comp Biochem Physiol Part D Genomics Proteomics. 2024 Mar 20:50:101228. doi: 10.1016/j.cbd.2024.101228. Online ahead of print.

Authors

Tangjian Zhou¹, Qian Meng², Ruijian Sun², Dafeng Xu², Fei Zhu², Chaofeng Jia², Shimiao Zhou¹, Shuyin Chen³, Yunxia Yang⁴

Affiliations

¹ Jiangsu Marine Fisheries Research Institute, Nantong 226007, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
² Jiangsu Marine Fisheries Research Institute, Nantong 226007, China.
³ Jiangsu Marine Fisheries Research Institute, Nantong 226007, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China. Electronic address: shuyinchen89@163.com.
⁴ Fisheries College, Zhejiang Ocean University, Zhoushan 316022, China. Electronic address: yangyx@zjou.edu.cn.

PMID: 38547756
DOI: 10.1016/j.cbd.2024.101228

Abstract

Black porgy (Acanthopagrus schlegelii) is an important marine aquaculture species in China. It is an ideal object for the cultivation of low-salinity aquaculture strains in marine fish and the study of salinity tolerance mechanisms in fish because of its strong low-salinity tolerance ability. Gill is the main osmoregulatory organ in fish, and the liver plays an important role in the adaptation of the organism to stressful environments. In order to understand the coping mechanisms of the gills and livers of black porgy in different salinity environments, this study explored these organs after 30 days of culture in hypoosmotic (0.5 ppt), isosmotic (12 ppt), and normal seawater (28 ppt) at histologic, physiologic, and transcriptomic levels. The findings indicated that gill exhibited a higher number of differentially expressed genes than the liver, emphasizing the gill's heightened sensitivity to salinity changes. Protein interaction networks and enrichment analyses highlighted energy metabolism as a key regulatory focus at both 0.5 ppt and 12 ppt salinity in gills. Additionally, gills showed enrichment in ions, substance transport, and other metabolic pathways, suggesting a more direct regulatory response to salinity stress. The liver's regulatory patterns at different salinities exhibited significant distinctions, with pathways and genes related to metabolism, immunity, and antioxidants predominantly activated at 0.5 ppt, and molecular processes linked to cell proliferation taking precedence at 12 ppt salinity. Furthermore, the study revealed a reduction in the volume of the interlamellar cell mass (ILCM) of the gills, enhancing the contact area of the gill lamellae with water. At 0.5 ppt salinity, hepatic antioxidant enzyme activity increased, accompanied by oxidative stress damage. Conversely, at 12 ppt salinity, gill NKA activity significantly decreased without notable changes in liver structure. These results underscore the profound impact of salinity on gill structure and function, highlighting the crucial role of the liver in adapting to salinity environments.

Keywords: Acanthopagrus schlegelii; Enzyme activity; Histology; Hypoosmotic; Isosmotic; RNA-Seq; Salinity.