Ribeiro B I, Love L B, Choi Y H, Hinrichs K
Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843-4466, USA.
Anim Reprod Sci. 2008 Oct;108(1-2):171-9. doi: 10.1016/j.anireprosci.2007.08.001. Epub 2007 Aug 15.
Use of assisted reproduction to obtain foals from valuable mares post-mortem typically necessitates holding of ovaries during shipment to a laboratory. The present study evaluated whether holding ovaries briefly at a warm ( approximately 30 degrees C) temperature improves meiotic and developmental competence of oocytes, as determined after maturation in vitro and intracytoplasmic sperm injection. Ovaries were packaged in pairs in insulated containers, and held either at 24 or 25-35 degrees C for 4h, followed by cooling. Ovaries in both treatments were held for either a short (mean, 7-7.4h) or long (mean, 20.6-20.7h) duration before oocyte recovery. Control ovaries were collected en masse at the abattoir. The ovary temperature in this treatment slowly decreased to approximately 27 degrees C; oocyte recovery was performed after 3.5-7h total holding. There was no effect of temperature on oocyte meiotic or developmental competence within either treatment time period. Oocytes in the short duration holding group had similar meiotic competence to controls, but had a significantly decreased rate (P<0.05) of blastocyst development. Oocytes in the long duration holding group had decreased (P<0.05) meiotic competence and blastocyst development compared to controls. These findings indicate that storage of equine ovaries for only 7h may decrease blastocyst development, and that longer storage reduces both rate of oocyte maturation and blastocyst development. Further work is needed to determine if there is a critical time before 7h post-mortem by which equine oocytes should be recovered to maximize developmental competence.
利用辅助生殖技术在珍贵母马死后获取马驹通常需要在运往实验室的过程中保存卵巢。本研究评估了在温暖(约30摄氏度)温度下短暂保存卵巢是否能提高卵母细胞的减数分裂和发育能力,这是在体外成熟和胞浆内精子注射后确定的。卵巢成对包装在隔热容器中,在24或25 - 35摄氏度下保存4小时,然后冷却。两种处理中的卵巢在卵母细胞回收前保存时间要么短(平均7 - 7.4小时)要么长(平均20.6 - 20.7小时)。对照卵巢是在屠宰场批量收集的。该处理中卵巢温度缓慢降至约27摄氏度;在总共保存3.5 - 7小时后进行卵母细胞回收。在任何一个处理时间段内,温度对卵母细胞的减数分裂或发育能力均无影响。短时间保存组的卵母细胞减数分裂能力与对照组相似,但囊胚发育率显著降低(P<0.05)。与对照组相比,长时间保存组的卵母细胞减数分裂能力和囊胚发育均降低(P<0.05)。这些发现表明,马卵巢仅保存7小时可能会降低囊胚发育,而更长时间的保存会降低卵母细胞成熟率和囊胚发育率。需要进一步的研究来确定在死后7小时之前是否存在一个关键时间,在此之前回收马卵母细胞可使发育能力最大化。