罗氏沼虾胚胎发育期主要消化酶和同工酶特性

采用生物化学方法分别测定了罗氏沼虾胚胎发育期5种消化酶:胃蛋白酶、类胰蛋白酶、淀粉酶、纤维素酶和脂肪酶的比活力,测定了6种同工酶:酯酶(EST)、苹果酸脱氢酶(MDH)、谷氨酸脱氢酶(GDH)、碱性磷酸酶(ALP)、乳酸脱氢酶(LDH)和淀粉酶(AMY)在成熟卵细胞和胚胎发育时期的表达特征。结果显示:5种消化酶的活力表现出两种变化趋势,即胃蛋白酶、类胰蛋白酶、淀粉酶和纤维素酶的酶活力呈现出“高—低—高”的变化趋势,而脂肪酶活力则呈现出下降的变化趋势。6种同工酶酶谱则随胚胎发育渐趋复杂,酶活性随之增强。研究表明,所测定的消化酶以及同工酶在罗氏沼虾受精卵期均已表现出酶活性,此阶段为卵源性的酶;原肠期是胚胎发育中一个较为重要的时期,胚胎内酶基因表达能力开始逐渐增强,开始合成一些酶类,为胚胎发育后期利用卵黄物质提供了保证。消化酶以及同工酶对卵黄物质的利用和胚胎发育的物质代谢起重要作用。

Characteristics of Several Digestive Enzymes and Isozyme during Embryonic Development in Prawn, Macrobrachium rosenbergii

Chemical and biological methods were employed to determine several digestive enzymes including pepsin,tryptase,amylase,cellulase and lipase and isozymes including esterase(EST),malic dehydrogenase(MDH),glutamate dehydrogenase(GDH),alkaline phosphatase(ALP),lactate dehydrogenase(LDH) and amylase(AMY) in mature ova and during embryonic development in prawn Macrobrachium rosenbergii.The results showed that the activities of pepsin,tryptase,amylase and cellulase were elevated in both the early and later embryonic stages,but depressed in mature ova and the middle stages of embryonic development,while the activity of lipase decreased.Isozymes zymogram turned to be complicated and their activities increased with embryos development.The enzymes were synthesized during gastrula stage.These enzymes ensured the utilization of yolk substance during later embryonic development.Digestive enzymes and isozymes played an important role in the process of utilization of yolk nutrients and metabolism of substances during embryonic development.