Unit of Reproduction and Obstetrics, Department of Animal Pathology, Faculty of Veterinary Medicine, University of Santiago de Compostela, Lugo, Spain.
Anim Reprod Sci. 2012 Aug;133(3-4):214-23. doi: 10.1016/j.anireprosci.2012.06.016. Epub 2012 Jun 27.
In this study we investigated the changes that in vitro incubation under capacitating conditions could induce on the motile sperm subpopulations present in frozen-thawed dog semen samples. In addition, cryopreserved dog spermatozoa were exposed to CCM (canine capacitating medium) solutions of 300, 150, 100 and 75 mOsm and the proportions of live spermatozoa with swollen tails were recorded (HOST+). Finally, frozen-thawed dog semen samples were submitted to a second cycle of freezing and thawing and the overall sperm motility, as well as the motile sperm subpopulations structure, was determined. Cryopreserved dog semen samples were structured in four sperm subpopulations with different motility characteristics: Subpopulation (Sp) 1 contained moderately rapid and progressive spermatozoa (25.2 ± 8.5%), Sp 2 included poorly motile and non progressive sperm (15.3 ± 8.1%), Sp 3 was represented by moderately slow non progressive sperm (14.9 ± 5.9%), and Sp 4 contained the most rapid and progressive sperm (20.8 ± 14.7%). After 3h of incubation under capacitating conditions, percentages of spermatozoa assigned to Sp 2 (6.1 ± 3.4%) and 3 (4.9 ± 2.8%) significantly decreased, whereas those assigned to Sp 1 (17.0 ± 11.2%) and 4 (16.2 ± 12.8%) did not significantly change. Significant correlations were found between percentages of HOST+, for the 3 osmolarities tested, and percentages of spermatozoa included in Sp 1 and 4 after 3 h of incubation in capacitating conditions or in Sp 4 after double freezing and thawing. These results indicated that subpopulations with the most rapid and progressive sperm seemed to be highly resistant to in vitro incubation in capacitating conditions and to osmotic stress, suggesting they are likely to be the source of the fertilizing population.
在这项研究中，我们研究了体外受精培养条件下对冷冻解冻犬精液样本中运动精子亚群的影响。此外，还将冷冻保存的犬精子暴露于渗透压为 300、150、100 和 75 mOsm 的 CCM（犬受精培养液）溶液中，并记录肿胀尾部的活精子比例（HOST+）。最后，将冷冻解冻的犬精液样本进行第二轮冷冻和解冻，并确定整体精子活力以及运动精子亚群结构。冷冻保存的犬精液样本分为具有不同运动特征的四个精子亚群：亚群（Sp）1 含有中等快速和渐进的精子（25.2 ± 8.5%），Sp 2 包括运动能力差且非渐进的精子（15.3 ± 8.1%），Sp 3 由中等慢速非渐进精子组成（14.9 ± 5.9%），Sp 4 包含最快和最具渐进性的精子（20.8 ± 14.7%）。在受精培养条件下孵育 3 小时后，Sp 2（6.1 ± 3.4%）和 Sp 3（4.9 ± 2.8%）的精子比例显著下降，而 Sp 1（17.0 ± 11.2%）和 Sp 4（16.2 ± 12.8%）的精子比例没有显著变化。在受精培养条件下孵育 3 小时后，发现 HOST+的百分比与 Sp 1 和 Sp 4 中的精子百分比之间存在显著相关性，在双重冷冻和解冻后，也发现 HOST+的百分比与 Sp 4 中的精子百分比之间存在显著相关性。这些结果表明，具有最快和最具渐进性的精子的亚群似乎对体外受精培养条件和渗透胁迫具有高度抵抗力，这表明它们可能是受精群体的来源。
