Turkish Journal of Fisheries and Aquatic Sciences
2021, Vol 21, Num, 1 (Pages: 01-07)
Effects of Different Levels of Salinity on NKA and NKCC Expression in Asian Sea Bass (Lates calcarifer)
2 Persian Gulf University, Persian Gulf Research Institute, Bushehr, Iran DOI : 10.4194/1303-2712-v21_1_01 Viewed : 2123 - Downloaded : 1715 Asian sea bass, Lates calcarifer is one of the most valuable marine fish species that is known to be tolerant to wide range changes of salinity. The species is able to live in freshwater, brackish and marine water, being an ideal model species for studying the effects of salinity on physiological responses. The present study is aimed to evaluate the changes in expression levels of Na+ -K + ATPase (NKA) and Na+/K+/2Cl– (NKCC) genes in gill tissue of L. calcarifer kept in a range of salinities including freshwater (0 ppt), brackish water (15 ppt) and saline marine water (35 and 50 ppt). Totals of 180 individuals were randomly distributed into 12 fiberglass tanks (volume 300 L) that contained different water salinity variants. After 30 days of experimental captivity, fish were euthanized and gill tissues were collected for NKA and NKCC mRNAs expression analysis. The U shape expression pattern for both NKA and NKCC was recorded. The highest brachial expression was seen in 50 ppt that was statistically different from all other salinity variants. The lowest expression was recorded in 35 ppt. In turns, observed NKA and NKCC expression levels in freshwater were significantly higher than 15 and 35ppt. The current findings showed that the expression levels of major gill transporters, as are NKA and NKCC has the highest expression in unusual conditions, having the lowest expression levels under the most habitual salinity conditions present in the wild environment. Keywords : Lates calcarifer, Salinity, Gill, NKCC, NKA