Phenotypic plasticity in gene expression and physiological response in red drum Sciaenops ocellatus exposed to a long-term freshwater environment
Phenotypic plasticity in gene expression and physiological response in red drum Sciaenops ocellatus exposed to a long-term freshwater environment
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DOI：
10.1007/s10695-017-0414-8
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发表时间：
2018-02-01
影响因子：
2.9
通讯作者：
Angel Vela-Magana, Miguel
中科院分区：
文献类型：
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作者：
Gullian Klanian, Mariel;Zapata Perez, Omar;Angel Vela-Magana, Miguel
红鼓鱼（眼斑拟石首鱼，Sciaenops ocellatus）是一种广盐性鱼类，常见于墨西哥湾以及北美洲大西洋沿岸。由于其较高的商业需求以及广盐性特征，该物种的水产养殖已从海水养殖系统多样化到低盐度养殖系统。近年来，人们对在内陆淡水系统中养殖红鼓鱼的可行性的兴趣日益增加，这促使我们研究其在淡水养殖系统中饲养8个月后的渗透调节能力。我们比较了在淡水驯化（FW）和海水（SW）环境中的红鼓鱼体内参与渗透调节过程的几个基因和酶的活性。基因表达谱是多样的：编码钠钾 - ATP酶（NKA）和囊性纤维化跨膜调节因子（CFTR）的基因在海水鱼中的表达略高于淡水鱼，而磷酸烯醇式丙酮酸羧激酶（PEPCK）和糖皮质激素受体信使RNA（mRNA）水平在淡水红鼓鱼中较高。淡水鱼的血浆钾总浓度比海水鱼低60.3%，鳃部钠钾 - ATP酶活性比海水鱼低63.5%。淡水红鼓鱼的磷酸烯醇式丙酮酸羧激酶活性是海水红鼓鱼的两倍。同样，淡水鱼的肝糖原比海水鱼高60%。总之，基因表达和酶活性数据都支持红鼓鱼的表型可塑性，并表明所观察到的离子稳态能力有限，特别是血浆钾浓度较低，是由于淡水的成分所致，并不一定反映其在渗透调节方面的生理无能。
Red drum (Sciaenops ocellatus) is a euryhaline fish commonly found in the Gulf of Mexico and along the Atlantic coast of North America. Because of high commercial demand and its euryhaline characteristics, aquaculture of this species has diversified from marine to low-salinity aquaculture systems. In recent years, interest in the feasibility of producing red drum in inland freshwater systems has grown and this prompted us to investigate its osmoregulatory capacity after rearing for 8 months in a freshwater aquaculture system. We compared the activities of several genes and enzymes involved in the osmoregulatory process in freshwater-acclimatized (FW) and seawater (SW) red drum. The gene expression profiles were variable: the expression of genes encoding Na+/K+-ATPase (NKA) and the cystic fibrosis transmembrane regulator (CFTR) was slightly higher in SW than FW fish, while phosphoenolpyruvate carboxykinase (PEPCK) and the glucocorticoid receptor messenger RNA (mRNA) levels were higher in FW red drum. The total plasma K concentration was 60.3% lower, and gill NKA activity was 63.5% lower in FW than in SW fish. PEPCK activity was twofold higher in FW than in SW red drum. Similarly, liver glycogen was 60% higher in FW fish. In summary, both gene expression and the enzyme activity data support the phenotypic plasticity of red drum and suggest that the limited capacity for ion homeostasis observed, in particular the low plasma K concentration, was due to the composition of freshwater and does not necessarily reflect a physiological inability to osmoregulate.