温度休克和静水压胁迫对鲤卵受精和胚胎亚显微结构的影响

Effects of Temperature Shock and Hydrostatic Pressure on Egg Fertilization and Embryo Ultrastructure in Common Carp

将部分人工催产和授精的优质松浦镜鲤Cyprinus carpio songpu受精卵在0~2℃的冰水中,冷休克胁迫15 min后于23~25℃水中发育;同批另一部分受精卵撒在细目筛网上,人工受精4 min后,迅速折叠筛网放入600 kg/cm2压力的静水压力器中3 min后,取出筛网于同温水中孵化。冷休克和静水压胁迫诱导开始后3 min、20 min、45 min、120 min、24 h和48 h各取10粒卵,固定在2.5%戊二醛中,在透射电子显微镜下观察受精和胚胎发育过程,与诱导组同期取样和同温水中孵化的受精卵为对照,研究三倍体制种方法对受精卵和胚胎发育的影响。结果表明:冷休克和静水压诱导组受精卵孵化率分别为51%和39%;仔鱼畸形率为15%和23%,死亡率为10%和17%。透射电镜观察发现,诱导后3~20 min,诱导组胚胎线粒体等细胞器严重受损,不同程度地破坏线粒体的内膜与嵴结构;静水压胁迫组尤为严重:细胞器空泡化,核糖体异常致密;这一现象在45 min之后逐渐好转;45~120 min可以观察到诱导组胚胎细胞器损伤水平开始逐渐恢复,空泡化细胞器大量减少,逐渐出现完整结构的线粒体,静水压胁迫组核糖体仍稍显致密;24~48 h时,诱导组细胞器损伤已经基本恢复;细胞器形态、数量与对照组无显著差异。本研究结果可为鱼类三倍体制种技术的完善提供理论依据。

Some high-quality common carp(Cyprinus carpio songpu)fertilized eggs were shocked in ice water at 0~2℃for 15 min,and then incubated in water at 23~25℃,and some common carp fertilized eggs in the same batch were fertilized in a fine screen in 4 min and quickly placed in a hydrostatic pressure at a pressure of 600 kg/cm2 for 3 min,and then the screen was taken out and incubated at 23~25℃.Ten eggs were sampled 3 min,20 min,45 min,120 min,24 h,and 48 h after cold shock and hydrostatic pressure induction,fixed in 2.5%glutaraldehyde,and the fertilization and embryo development were observed under a transmission electron microscope to evaluate the effects of the triploid breeding method on fertilized eggs and embryo development.The fertilized eggs were sampled,fertilized,and incubated as the same as those in the induction groups,only without cold shock and hydrostatic pressure induction as a control group.It was found that the hatching rate was 51%in the cold-shock induced group and 39%in the hydrostatic induced group,with abnormal rate of 15%and mortality rate of 10%in larvae in cold-shock group,and abnormal rate of 23%and mortality rate of 17%in larvae in hydrostatic pressure group.The transmission electron microscopy revealed that the organelles including mitochondria were severely damaged,and the inner membrane and ridge structure of mitochondria were also damaged to some extent 3~20min after induction in the induction group,especially,with organelle vacuolation and abnormally dense ribosomes in the hydrostatic pressure group.In 45 min induction,however,the phenomenon began to be improved gradually in the induction groups;45~120 min,the level of organelle damage appeared to gradually recover,and vacuolated organelles were greatly reduced in the induction group.The complete structure of mitochondria gradually appeared,and the ribosome was still slightly dense in the hydrostatic stress group.During 24~48 h,the organelle damage had basically recovered in the induction group compared with the control group,cold shock and hydrostatic pressure,without difference in the shape and number of organelles between the induction group and control.The findings are intended to provide a theoretical basis for the improvement of fish triple-species technology.