Rizzo Elizete, Godinho Hugo Pereira, Sato Yoshimi
Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, P.O. Box 486, 30161-970 Belo Horizonte, MG, Brazil.
Theriogenology. 2003 Oct 1;60(6):1059-70. doi: 10.1016/s0093-691x(03)00108-0.
The loss of oocyte viability after ovulation is one of the limiting factors in controlled reproduction of several fish species. Experiments were performed with 15 feral Prochilodus marggravii female fish induced to spawn with crude carp pituitary extract to evaluate the viability of oocytes retained within the ovarian cavity (in situ storage) and outside of the ovarian cavity (ex situ storage). Because fertility rates rapidly declined after ovulation, simultaneously with an increase in the number of deformed larvae, P. marggravii oocytes could only be successfully stored for 1 h ex situ at room temperature ( approximately 26 degrees C). There was a highly negative correlation (r = -0.82) between fertilization and deformed larvae during in situ storage at approximately 26 degrees C. Ex situ cooling (18 degrees C) caused a drastic reduction in fertilization rates as compared with storage at approximately 26 degrees C. Oocyte structure was preserved during 2 h storage and the cortical reaction was induced before spawning. Since the micropylar apparatus remained open, it was not the primary cause for the loss of oocyte fertility. The cytoskeleton of the oocyte appeared to be affected since ooplasmic segregation was altered after 2 h storage.
排卵后卵母细胞活力的丧失是几种鱼类可控繁殖的限制因素之一。对15条野生马氏原唇齿脂鲤雌鱼进行实验，用鲤鱼脑垂体粗提物诱导其产卵，以评估留在卵巢腔内（原位保存）和卵巢腔外（异位保存）的卵母细胞的活力。由于排卵后受精率迅速下降，同时畸形幼虫数量增加，马氏原唇齿脂鲤的卵母细胞在室温（约26℃）下异位保存只能成功保存1小时。在约26℃原位保存期间，受精与畸形幼虫之间存在高度负相关（r = -0.82）。与在约26℃保存相比，异位冷却（18℃）导致受精率大幅降低。卵母细胞结构在保存2小时期间得以保留，并且在产卵前诱导了皮质反应。由于卵孔装置保持开放，它不是卵母细胞受精能力丧失的主要原因。卵母细胞的细胞骨架似乎受到了影响，因为保存2小时后卵质分离发生了改变。
