厦门港海区真刺唇角水蚤不同季节种群的同工酶分析

AN ISOENZYME ANALYSIS ON DIFFERENT SEASONAL POPULATIONS OF THE PLANKTONIC COPEPOD,LABIDOCERA EUCHAETA, IN XIAMEN WATERS

于1989年10月—1990年1月在厦门港海区采集真刺唇角水蚤,对其不同季节种群4种酶的6个酶区,即:苹果酸酶(ME)、苹果酸脱氢酶(MDH)、醛氧化酶(AOX_1,AOX_2)和酯酶(EST_1,EST_2)进行了分析。结果表明,苹果酸酶和苹果酸脱氢酶是单态的,而其余的两种酶是多态的。除了EST_2之外,冬春种群与夏秋种群在其余5个酶区的等位基因频率非常相似;EST_2在有的个体不出现酶带,冬春种群的表达频率高于夏秋种群。温度对EST有明显的影响,在55℃中EST_1和EST_2全部失活;在45℃以下各温度组中EST_1的表达频率全部为1,但在EST_2则有所变化,变化规律与自然种群的相近。

Six loci of four enzymes, malic enzyme ( ME), malic dehydrogenase (MDH), aldehyde oxidase (AOX1, AOX2) and esterase (EST1, EST2), were studied in the different seasonal populations of the planktonic copepod Labidocera euchaeta collected from Xiamen waters during Oct. 1989-Jan. 1990. ME and MDH are monomorphic, while AOX and EST are polymorphic. The allelic frequencies of five loci, except for EST2, do not distinguish the winter-spring and summer-fall populations. EST2 is not expressed in some individuals. The expression frequency of EST2 is higher in the collections of winter and spring than those of summer and fall. Temperature exerts a remarkable effect on EST phenotype. All inactivation of EST1 and EST2 occurs at 55℃. The expression frequency in separated temperature groups below 45℃ for EST1 is 1, and is subject to variation for EST2, being similar to the seasonal variation in natural populations.