细胞质膜在罗非鱼和叉尾斗鱼低温驯化过程中的功能

摘要

In this study, we initially compared the cold tolerance of the Genetically Improved Farmed Tilapia (GIFT) strain of Nile tilapia (Oreochromis niloticus) and the paradise fish (Macropodus opercularis) with a series of scientific indices, such as the temperature at death (TAD), the cumulative degree hours (CDH) and the survival curves. Next, we systematically studied the effects of low temperatures on a series of plasma membrane-related physiological functions, such as membrane fluidity, endocytosis and the activity of the membrane protein Na+, K+-ATPase in both species. The results showed that the paradise fish had a better cold tolerance than did the GIFT. The plasma membrane-related physiological functions were all sensitive in low temperatures of both fishes. However, these sensitivities were different between the hardy species (paradise fish) and the non-hardy species (GIFT). The patterns and tendencies concerning sensitivity changes during varied temperatures were consistent in each species. All these interspecific differences and intras-pecific consistence highlighted the importance of the membrane fluidity during the cold acclimation. These results suggest that the plasma membrane, particularly membrane fluidity, may play an important role in cold acclimation of the two fish species.%研究通过一系列科学的指标，比如死亡温度、累计温度处理时间和存活率曲线，检测并比较了吉富罗非鱼和叉尾斗鱼的低温耐受能力，然后系统地检测了在两种鱼中，低温对一系列与细胞膜相关的生理指标的影响，包括细胞膜流动性、内吞作用和膜蛋白Na+， K+-ATPase的活性。实验结果显示叉尾斗鱼比吉富罗非鱼有着明显优良的耐寒力。两种鱼内与细胞膜相关的生理指标都对温度敏感，但是具体的敏感程度却在耐寒种(叉尾斗鱼)和不耐寒种(吉富罗非鱼)之间存在显著差异。在具体每个物种内部，与细胞膜相关的一系列生理功能对温度的敏感程度是一致的。所有这些种间差异性和种内一致性都使得细胞膜流动性在物种耐寒过程中的重要性凸显出来。结果揭示细胞质膜，尤其是质膜流动性可能在这两种鱼对低温适应过程中扮演重要的角色。