Carbonic anhydrase 2-like and Na+-K+-ATPase α gene expression in medaka (Oryzias latipes) under carbonate alkalinity stress

Abstract

High carbonate alkalinity is one of the major stress factors for living organisms in saline-alkaline water areas. Acute and chronic effects of carbonate alkalinity on expression of two genes, carbonic anhydrase 2-like (CA2-like) and Na(+)-K(+)-ATPase α subunit (NKA-α) mRNA in medaka (Oryzias latipes) were evaluated to better understand the responses important for coping with a carbonate alkalinity stress. In the acute exposure experiment, the expression of CA2-like and NKA-α mRNA in the gill and kidney of medaka were examined from 0 h to 7 days exposed to 30.4 mM carbonate alkalinity water. Exposure to high carbonate alkalinity resulted in a transitory alkalosis, followed by a transient increase in gill and kidney CA2-like and NKA-α mRNA expression. In the chronic exposure experiment, the expression of these two genes was examined in the gill and kidney at 50 days post-exposure to six different carbonate alkalinity concentrations ranging from 1.5 to 30.4 mM. Gill and kidney CA2-like mRNA levels in 30.4 mM were approximately 10 and 30 times higher than that of the control (1.5 mM), respectively. Less differences were found in NKA-α expression in the 50-days exposure. The results indicate that when transferred to high carbonate alkalinity water, a transitory alkalosis may occur in medaka, followed by compensatory acid-base and ion regulatory responses. Thus, CA2-like and NKA-α are at least two of the important factors that contribute to the regulation of alkalinity stress.

Analysis revealed the molecular mechanism of oxidative stress-autophagy-induced liver injury caused by high alkalinity: integrated whole hepatic transcriptome and metabolome

“…The area of saline–alkaline land in Northeast China is approximately 3.78 × 10 6 hm2, and most is carbonate saline–alkaline land ( 3 , 4 ). The saline–alkaline water in the region has characteristics such as low salinity, high alkalinity, and high pH, resulting in low bioavailability ( 5 ). The development of fisheries in regions of saline‒alkaline water is important in the utilization of abundant environmental resources.…”

“…The development of fisheries in regions of saline‒alkaline water is important in the utilization of abundant environmental resources. The high alkalinity of saline–alkaline water is highly detrimental to fish, threatening their growth and health and limiting the development of the aquaculture industry ( 5 – 7 ). The water in Qinghai Lake has high alkalinity (carbonate alkalinity of approximately 29 mM, pH 9.1-9.5) ( 8 ).…”

Effects of Saline-Alkaline Stress on Metabolome, Biochemical Parameters, and Histopathology in the Kidney of Crucian Carp (Carassius auratus)

“…CA is considered a crucial stress factor as it affects the survival of aquatic animals in saline-alkali water [ 6 ]. Previous studies have shown that carbonate alkalinity could cause a series of problems for aquatic animals, such as respiratory and metabolic alkalosis [ 7 ], tissue oxidative damage [ 8 ], intestinal flora imbalance [ 9 ], as well as disorders of the antioxidant and immune system [ 10 ], which seriously affect the normal growth, development and reproduction of fish. At the same time, recent studies have shown that the extent of freshwater salinization continues to deepen as a result of human activities and global warming, which might steadily shrink the available space for freshwater aquaculture [ 11 , 12 ].…”

Reducing Dietary Protein Content by Increasing Carbohydrates Is More Beneficial to the Growth, Antioxidative Capacity, Ion Transport, and Ammonia Excretion of Nile Tilapia (Oreochromis niloticus) under Long-Term Alkalinity Stress

“…Alkalinity stress is considered the main stress in salinealkali water habitats and can suppress the growth, reproduction, development, survival, and even intestinal microflora of aquatic animals [8,9]. Alkalinity stress increases the blood HCO 3 − concentration and disrupts the balance of NH 3 and NH 4 + due to a lack of H + , which finally results in ammonia poisoning [10].…”