Roth T L, Bush L M, Wildt D E, Weiss R B
Center for Research of Endangered Wildlife, Cincinnati Zoo and Botanical Garden, Cincinnati, Ohio 45220, USA.
Biol Reprod. 1999 Feb;60(2):493-8. doi: 10.1095/biolreprod60.2.493.
A heterologous bovine in vitro fertilization (IVF) system was used to study the functional competence of scimitar-horned oryx spermatozoa after cryopreservation. Four sperm-freezing methods were compared after dilution of ejaculates from six oryx with an equine semen extender: 1) dry ice, 2) dry shipper one-step, 3) dry shipper two-step, and 4) liquid nitrogen vapor. Post-thaw sperm motility, longevity, and acrosomal status were assessed and zona pellucida penetration, fertilization, and embryo cleavage were evaluated after coincubation of thawed oryx spermatozoa with in vitro-matured domestic cow oocytes. Sperm motility index (SMI) decreased (p < 0.05) over a 6-h period, but a high percentage (>/= 65%) of spermatozoa contained intact acrosomes in all treatments. Despite differences in sperm motility among methods, oocyte penetration, fertilization, and embryo cleavage did not differ (p >/= 0.05). However, cleavage success was < 50% across all treatments. There were positive correlations (p < 0.05; r = 0.81-0.97) between sample SMI at 3 and 6 h and fertilization, penetration, and cleavage, but no correlations (p >/= 0.05) between SMI at 0 or 1 h and IVF success. This study demonstrates that compatible heterologous gamete interaction allows thorough assessment of post-thaw sperm function in an endangered antelope. Scimitar-horned oryx spermatozoa appear relatively tolerant of varied cryopreservation methods, and preserved samples exhibit adequate post-thaw function to warrant use for assisted reproduction.
利用一种异源牛体外受精（IVF）系统研究弯刀角大羚羊精子冷冻保存后的功能活性。用马精液稀释剂稀释6只大羚羊的射精后，比较了4种精子冷冻方法：1）干冰法；2）干式运输箱一步法；3）干式运输箱两步法；4）液氮蒸汽法。评估解冻后精子的活力、存活时间和顶体状态，并在解冻后的大羚羊精子与体外成熟的家牛卵母细胞共同孵育后，评估透明带穿透率、受精率和胚胎分裂率。精子活力指数（SMI）在6小时内下降（p<0.05），但在所有处理中，高比例（≥65%）的精子顶体完整。尽管不同方法之间精子活力存在差异，但卵母细胞穿透率、受精率和胚胎分裂率并无差异（p≥0.05）。然而，所有处理的分裂成功率均<50%。3小时和6小时时样本SMI与受精、穿透和分裂之间存在正相关（p<0.05；r=0.81-0.97），但0小时或1小时时的SMI与IVF成功率之间无相关性（p≥0.05）。本研究表明，兼容的异源配子相互作用能够全面评估濒危羚羊解冻后精子功能。弯刀角大羚羊精子似乎对多种冷冻保存方法具有相对耐受性，且保存后的样本解冻后功能良好，足以用于辅助生殖。
