红螯螯虾胚胎发育期主要消化酶和同工酶的活性变化

Changes in Main Digestive Enzyme and Isozyme Activities during Embryonic Development of Redclaw Crayfish

采用生物化学方法测定了红螯螯虾(Cherax quadricarinatus)胚胎发育各期主要消化酶(胃蛋白酶、胰蛋白酶、淀粉酶、纤维素酶和脂肪酶)的比活力及主要同工酶(乳酸脱氢酶、苹果酸脱氢酶、葡萄糖-6-磷酸脱氢酶和酯酶)的活力。结果显示,5种消化酶各自表现出不同的变化模式,胃蛋白酶和胰蛋白酶的比活力早期均逐渐上升,到发育后期胃蛋白酶出现快速下降,而胰蛋白酶却仍保持较高水平;淀粉酶比活力呈“V”字型变化趋势,晚期活性较高;纤维素酶和脂肪酶的比活力则均较低。4种同工酶酶谱随胚胎的发育渐趋复杂,酶活性也随之增强。结果表明,消化酶和同工酶活力的高低均受其基因的调控,并随胚胎发育适时表达,为胚胎组织、器官和系统的形成以及未来仔虾的开口摄食提供物质保证。

The objectives of the present study were to investigate the changes in main digestive enzymes （pepsin, trypsin, amylase, cellulase, lipase） and isozymes （LDH, MDH, G6PD, EST） during embryonic development of Redclaw Crayfish （ Cherax quadricarinatus ）. The results showed that all five digestive enzymes had some activities and their activities changed differently. Pepsin and trypsin specific activities were gradually increased in earlier embryonic development stages, but pepsin activity decreased rapidly in later stages and trypsin activity still kept at a high level. Amylase specific activity changed as ＂V＂ pattern and reached high values in later stages. Cellulase and lipase specific activities all showed relatively low values. The four isozyme patterns were complicated and their activities enhanced correlating with the stages of embryonic development. The results suggest that digestive enzyme and isozyme activities are controlled by their genes and expressed in sequence during embryonic development, which provides construre and energy substances for the formation of tissues, organs and systems, and guaranty to the feeding of larvae.