香鱼(Plecoglossus altivelis)排卵后卵内油球、酶活、丙二醛及受精率、孵化率的变化

VARIATIONS OF PLECOGLOSSUS ALTIVELIS OOCYTE DURING POST-OVULATORY AGING ON THE LIPID DROPLET,ENZYME ACTIVITY,MDA,FERTILIZATION AND HATCHING RATES

以香鱼卵母细胞为研究对象,采用观察卵内油球、有关酶的活力、以及卵的受精率和孵化率等变化的方法,研究了香鱼卵母细胞长时效演化的相关机理,结果表明,随着香鱼卵在腹腔内保存时间的延长,卵内油球从0h的油球直径≤10μm,且均匀分布,逐渐融合增大,至108h增大到120μm,油球数仅有5—6个。同时,SOD、POD的活力及MDA含量均呈先升后降的变化趋势,最大峰值分别出现在60h、36h和24h。随着油球和酶活的变化,卵子质量逐渐下降,表现为受精率和孵化率的降低:排卵后24h、48h、72h、96h的受精率分别为94.37%、88.19%、50.20%、10.83%,孵化率分别为85.78%、68.14%、25.54%、0.53%。

Ayu Plecoglossus altivelis is a migrational fish without mesovarium. In the abdominal cavity, the oocyte is protected by the abdominal cavity fluid which can store it for a long time with a high fertilization potential. During this period the quality of the oocyte becomes low, choice of the maturation of adult ayu was based on the acquisition of the oocyte and sperm such that for the same female fish the acquisition of oocyte repeated per 12 hours. A part of each oocyte batch which was used for fertilization remained for observation. Through observation it was expected that there would be some differences between different egg batches including oocyte morphology, color and morphology of the lipid droplet. As the time that eggs stored in the abdominal cavity increased, the oocyte quality was lowered and this was reflected by the diameter of the lipid droplet becoming ≤ 10μm to 120tam from Oh to 96h and the amount of the lipid droplet only being five or six at 108h. The activity of SOD, POD and the content of MDA increased at the beginning then descended, and they exhibited the highest level at 60, 36 and 24 hours. With the variations of the lipid droplet and enzyme activity, egg quality declined gradually. Thus, while 94.37% fertilization rate and 85.78% hatching rate were observed, in average, at 24h, fertilization and hatching rate dropped to 88.19% and 68.14% at 48h, to 50.20% and 25.54% at 72h, and to 10.83% and 0.53% at 96h.