Rh proteins and H+ transporters involved in ammonia excretion in Amur Ide (Leuciscus waleckii) under high alkali exposure

Xue Fei Zhao; Jing Huang; Wen Li; Shuang Yi Wang; Li Qun Liang; Li Min Zhang; Hon Jung Liew; Yu Mei Chang

doi:10.1016/j.ecoenv.2024.116160

Rh proteins and H⁺ transporters involved in ammonia excretion in Amur Ide (Leuciscus waleckii) under high alkali exposure

Ecotoxicol Environ Saf. 2024 Mar 15:273:116160. doi: 10.1016/j.ecoenv.2024.116160. Epub 2024 Mar 2.

Authors

Xue Fei Zhao¹, Jing Huang², Wen Li³, Shuang Yi Wang⁴, Li Qun Liang², Li Min Zhang², Hon Jung Liew⁵, Yu Mei Chang⁶

Affiliations

¹ National and Local Joint Engineering Laboratory for Freshwater Fish Breeding, Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin 150070, China; College of Wildlife and Protected Area, Northeast Forestry University, Harbin 150040, China.
² National and Local Joint Engineering Laboratory for Freshwater Fish Breeding, Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin 150070, China.
³ National and Local Joint Engineering Laboratory for Freshwater Fish Breeding, Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin 150070, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 2000, China.
⁴ National and Local Joint Engineering Laboratory for Freshwater Fish Breeding, Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin 150070, China; BGI Genomics, BGI-Shenzhen, Shenzhen, Guangdong 518083, China.
⁵ Higher Institution Center of Excellence (HICoE), Institute of Tropical Aquaculture and Fisheries, Universiti of Malaysia Terengganu, Kuala Nerus, Terengganu 21030, Malaysia.
⁶ National and Local Joint Engineering Laboratory for Freshwater Fish Breeding, Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin 150070, China. Electronic address: [email protected].

PMID: 38432157
DOI: 10.1016/j.ecoenv.2024.116160

Abstract

High alkaline environment can lead to respiratory alkalosis and ammonia toxification to freshwater fish. However, the Amur ide (Leuciscus waleckii), which inhabits an extremely alkaline lake in China with titratable alkalinity up to 53.57 mM (pH 9.6) has developed special physiological and molecular mechanisms to adapt to such an environment. Nevertheless, how the Amur ide can maintain acid-base balance and perform ammonia detoxification effectively remains unclear. Therefore, this study was designed to study the ammonia excretion rate (T_amm), total nitrogen accumulation in blood and tissues, including identification, expression, and localization of ammonia-related transporters in gills of both the alkali and freshwater forms of the Amur ide. The results showed that the freshwater form Amur ide does not have a perfect ammonia excretion mechanism exposed to high-alkaline condition. Nevertheless, the alkali form of Amur ide was able to excrete ammonia better than freshwater from Amur ide, which was facilitated by the ionocytes transporters (Rhbg, Rhcg1, Na⁺/H⁺ exchanger 2 (NHE2), and V-type H⁺ ATPase (VHA)) in the gills. Converting ammonia into urea served as an ammonia detoxication strategy to reduced endogenous ammonia accumulation under high-alkaline environment.

Keywords: Acid transporters; Alkali tolerant fish; Alkalinity; Ammonia excretion; Ammonia transporters.

MeSH terms

Alkalies
Ammonia* / metabolism
Ammonia* / toxicity
Animals
Cypriniformes*
Gills / metabolism
Lakes
Membrane Transport Proteins / metabolism

Substances

Ammonia
Membrane Transport Proteins
Alkalies