Seawater carbonate chemistry and expression of c-Fos protein in the brain of marine medaka

• Main Authors: Wang, Xiaojie, Lv, Yutao, Xie, Jinling, Li, Baolin, Zhou, Tangjian, Chen, Yaqi, Chen, Yi, Song, Jiakun
• Format: Dataset
• Language: English
• Published: PANGAEA 2020
• Subjects: Alkalinity; total; standard deviation; Animalia; Aragonite saturation state; Behaviour; Bicarbonate ion; Bottles or small containers/Aquaria (<20 L); Calcite saturation state; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Chordata; Coast and continental shelf; Experiment duration; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Gene expression; Gene expression (incl. proteomics); Laboratory experiment; Nekton; North Pacific; OA-ICC; Ocean Acidification International Coordination Centre; Oryzias melastigma; Partial pressure of carbon dioxide; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Pelagos; pH; Potentiometric; Potentiometric titration; Proportion; Proportion of time; Registration number of species; Salinity; Single species; Species; Speed; Pacific; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.920009; https://doi.org/10.1594/PANGAEA.920009

Altered behaviors have been reported in many marine fish following exposure to high CO2 concentrations. However, the mechanistic link between elevated CO2 and activation of brain regions in fish is unknown. Herein, we examined the relative quantification and location of c-Fos expression in marine medaka following acute (360 min) and short-term (7 d) exposure to CO2-enriched water (1000 ppm and 1800 ppm CO2). In the control and two treatment groups, pH was stable at 8.21, 7.92 and 7.64, respectively. After acute exposure to seawater acidified by enrichment with CO2, there was a clear upregulation of c-Fos protein in the medaka brain (P < 0.05). c-Fos protein expression peaked after 120 min exposure in the two treatment groups and thereafter began to decline. There were marked increases in c-Fos-labeling in the ventricular and periventricular zones of the cerebral hemispheres and the medulla oblongata. After 1800 ppm CO2 exposure for 7 d, medaka showed significant preference for dark zones during the initial 2 min period. c-Fos protein expression in the ventricular and periventricular zones of the diencephalon in medaka exposed to 1000 ppm and 1800 ppm CO2 were 0.51 ± 0.10 and 1.34 ± 0.30, respectively, which were significantly higher than controls (P < 0.05). Highest doublecortin protein expression occurred in theventricular zones of the diencephalon and mesencephalon. These findings suggest that the ventricular and periventricular zones of the cerebral hemispheres and the medulla oblongata of marine medaka are involved in rapid acid-base regulation. Prolonged ocean acidification may induce cell mitosis and differentiation in the adult medaka brain.