|Budget Amount *help
¥46,670,000 (Direct Cost: ¥35,900,000、Indirect Cost: ¥10,770,000)
Fiscal Year 2013: ¥5,850,000 (Direct Cost: ¥4,500,000、Indirect Cost: ¥1,350,000)
Fiscal Year 2012: ¥9,230,000 (Direct Cost: ¥7,100,000、Indirect Cost: ¥2,130,000)
Fiscal Year 2011: ¥9,230,000 (Direct Cost: ¥7,100,000、Indirect Cost: ¥2,130,000)
Fiscal Year 2010: ¥22,360,000 (Direct Cost: ¥17,200,000、Indirect Cost: ¥5,160,000)
In the present study, we aimed to clarify molecular and cellular mechanisms of fish osmoregulation, and seek a possibility to apply fish osmoregulatory studies to fisheries industry. First, we clarified the functional plasticity and life cycle of gill ionocytes in tilapia. Second, gill ionocytes were demonstrated to excrete potassium, and the molecular mechanism of potassium excretion was shown in tilapia. Cesium was also secreted from gill ionocytes through the potassium-excreting mechanism. Finally, the involvement of free amino acids in intracellular osmoregulation was shown in tilapia and puffer fish. It is highly possible that temporal exposure of fish to higher salinity water causes a transient increase in intracellular amino acid concentration, resulting in a transient increase in fish meat taste.