Gil M A, Roca J, Cremades T, Hernández M, Vázquez J M, Rodríguez-Martínez H, Martínez E A
Department of Medicine and Animal Surgery, Faculty of Veterinary Medicine, University of Murcia, 30071 Murcia, Spain.
Theriogenology. 2005 Jul 15;64(2):305-16. doi: 10.1016/j.theriogenology.2004.11.024. Epub 2005 Jan 5.
The objective of this study was to determine if a multivariate pattern analysis of frozen-thawed sperm characteristics of boar semen of unknown fertility, thus identifying groups of ejaculates as "good" or "bad" freezers, would estimate their fertilizing potential in an in vitro embryo production (IVP) system. Frozen-thawed spermatozoa from a single ejaculate collected from 46 boars were evaluated for sperm motility and kinematic patterns, for sperm viability and for early changes in sperm membrane stability. All data generated were used for a multivariate pattern analysis (PATN; CSIRO, Canberra, Australia) which objectively classified all ejaculates within a data set in to one of two groups, categorised as "good" (n = 25) or "bad" (n = 21) according with their freezability. In vitro matured oocytes were exposed to 2000 or 4000 frozen-thawed spermatozoa per oocyte for 6h and then cultured in embryo culture medium for either 6h (assurance of fertilization) or 7 days (to collect data on embryo development). Rates of sperm oocyte penetration and of embryo development significantly (p < 0.05) increased in a sperm:oocyte ratio-dependent manner. A similar pattern was observed when sperm characteristics were grouped. Indeed, ejaculates classified as "good" showed significantly (p < 0.05) higher rates of oocyte penetration, cleavage and of blastocyst formation than those classified as "bad". However, variation was still present among individuals (ejaculates, boars) in their ability to produce blastocysts in vitro. It is therefore concluded that despite the presence of a relationship for ejaculates with good semen quality post-thaw (thus grouped as "good") to higher IVP-results, the presence of individual variation does not allow for an accurate estimation of in vitro fertility based solely on the frozen-thawed semen quality parameters of a single ejaculate from a given boar.
本研究的目的是确定对生育力未知的公猪精液冻融后的精子特征进行多变量模式分析，从而将射精样本分为“优质”或“劣质”冷冻组，是否能在体外胚胎生产（IVP）系统中评估其受精潜力。对从46头公猪采集的单次射精的冻融精子进行评估，检测精子活力和运动模式、精子活力以及精子膜稳定性的早期变化。所产生的所有数据用于多变量模式分析（PATN；澳大利亚堪培拉联邦科学与工业研究组织），该分析客观地将数据集中的所有射精样本分为两组之一，根据其冷冻能力分为“优质”（n = 25）或“劣质”（n = 21）。将体外成熟的卵母细胞与每枚卵母细胞2000或4000个冻融精子接触6小时，然后在胚胎培养基中培养6小时（确保受精）或7天（收集胚胎发育数据）。精子卵母细胞穿透率和胚胎发育率以精子：卵母细胞比例依赖的方式显著（p < 0.05）增加。当对精子特征进行分组时也观察到类似模式。实际上，分类为“优质”的射精样本显示出比分类为“劣质”的样本显著（p < 0.05）更高的卵母细胞穿透率、卵裂率和囊胚形成率。然而，个体（射精样本、公猪）在体外产生囊胚的能力方面仍存在差异。因此得出结论，尽管解冻后精液质量良好的射精样本（因此归为“优质”）与更高的IVP结果之间存在关联，但个体差异的存在使得仅根据来自给定公猪的单次射精的冻融精液质量参数无法准确估计体外受精能力。
