荷那龙罗非鱼和莫桑比克罗非鱼3种同工酶的分析

采用聚丙烯酰胺凝胶垂直电泳法分析了酯酶(EST)、超氧化物歧化酶(SOD)和乳酸脱氢酶(LDH)3种同工酶在荷那龙罗非鱼O reochrom is hornorum和莫桑比克罗非鱼O.m ossam bicus肝脏、心脏、肌肉、脑和肾脏5种器官组织中的表达情况。结果表明,两种罗非鱼的这3种同工酶均具有明显的组织特异性。EST在两种罗非鱼的肝脏中表达最强,带型最复杂;EST还有种的特异性,如EST-7和EST-8仅分别存在于莫桑比克罗非鱼的心脏和脑器官中,可作为鉴别两种罗非鱼的标记;两种鱼的EST同工酶还具有多态现象。SOD和LDH在两种罗非鱼的酶谱表型、活性等方面非常相似。SOD在肌肉组织中的酶带条数最多,且多数酶带的表达量较高,而LDH在脑、肾脏中表达丰富。同工酶分析结果反映了两种罗非鱼具有较近的亲缘关系,是种间杂交的基础;同时说明两种罗非鱼含有供选择的等位基因,可用于良种选育。

Preliminary study on three isozymes of Oreochromis hornorum and Oreochromis mossambicus

The expression of three isozymes,esterase(EST),superoxide dismutase(SOD) and lactate dehydrogenase(LDH) were analyzed in five tissues including liver,heart,muscle,brain and kidney of Oreochromis hornorum and Oreochromis mossambicus using the vertical polyacrylamide gel electrophoresis method.The results showed that EST,SOD and LDH expressed with significant tissue-specificity.Highest expression level and the most complex patterns of EST were observed in liver.Expression of EST had been species-specificity,EST-7 and EST-8 were only found in heart and brain of O.mossambicus,respectively,which could be used as genetic markers to distinguish these two species.Polymorphous expression of EST was observed in these two fishes.The zymograms and activities of SOD and LDH were similar in two tilapias.Highest level of SOD had been found in muscle while LDH was in brain.The results indicated that the two tilapias have close relationship and both fishes had genetic types suitable for breeding selection.