Gill’s cells: use of structural changes and fatty acid signature of basolateral membrane as potential early-warning biomarkers to assess the exposure to atrazine in sea lamprey downstream migrants

Abstract

For decades in Portugal, atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) was one of the most applied herbicide in several crops growth/production, and despite being ban in 2007 it is still detected in surface and groundwater. The juvenile sea lamprey may be particularly vulnerable to contaminants such as atrazine as well as others of the group of chloro-s-triazines as it migrates from the fresh to the marine environment to start the parasitic phase of the life cycle. Therefore, this study was carried out in order to assess if cellular alterations of gill chloride cells and the fatty acid profile of basolateral membrane could be considered as early-warning signals of atrazine effect in order to assess the impact of stressors on the recruitment success of sea lamprey juvenile populations. Lampreys were exposed to atrazine at concentrations of 50 and 100 µg/L during acclimation (0 to 35‰) and changes in the structure of gill cells, gill Na+K+ATPase activity and phospholipid fatty acid composition of the basolateral membrane system were monitored. The results shown that observed cellular alterations as well as gill cells´ BLM phospholipids fatty acid signature are sensitive to ATZ exposure and could be considered early-warning biomarkers in sea lamprey´s juveniles.