Daigneault Bradford W, McNamara Kelli A, Purdy Phillip H, Krisher Rebecca L, Knox Robert V, Miller David J
Department of Animal Sciences, University of Illinois, Urbana-Champaign, Illinois, USA.
United States Department of Agriculture-Agricultural Research Service-National Center for Genetic Resources Preservation-National Animal Germplasm Program, Fort Collins, Colorado, USA.
Theriogenology. 2014 Jul 15;82(2):266-73. doi: 10.1016/j.theriogenology.2014.04.006. Epub 2014 Apr 23.
Cryopreserved semen allows the use of single ejaculates for repeated analyses, potentially improving IVF consistency by eliminating interejaculate variability observed with fresh semen. However, the freezing and thawing processes result in compromised sperm function and IVF success. Semen samples are often screened for motility before use for IVF. Samples that are below a designated motility threshold may be discarded. Our objectives were to determine if post-thaw sperm motility, other traits that may be indicative of sperm function, or a novel assay of oviduct binding were related to IVF success. Semen from 16 boars was cooled to 15 °C for overnight shipment before cryopreservation. Semen was thawed and motility was recorded microscopically and confirmed using computer-automated sperm assessment. Each sample was tested by IVF in two to three independent replicates. Regression and correlation analyses were employed to determine the interrelationships between sperm traits and the relationships between post-thaw motility, sperm-oviduct binding and IVF outcomes. Among the sperm traits examined, sperm acrosome integrity was negatively correlated with post-thaw motility (r(2) = 0.64) but not with IVF results. The number of sperm bound to oviduct aggregates was correlated with IVF polyspermy rates (r(2) = 0.62, P < 0.05) but less with overall IVF rates (r(2) = 0.31, P > 0.10). There was some relationship of post-thaw motility with IVF monospermic fertilization (P = 0.06, r(2) = 0.08) but not to other IVF outcomes. Our results indicate that post-thaw motility of frozen-thawed boar sperm is strongly related to acrosome integrity but has limited use for predicting IVF success. The number of sperm bound to oviduct cells was related to IVF polyspermy rates and may be more indicative of in vitro sperm function than traditional sperm motility and acrosome status evaluation.
冷冻保存的精液允许使用单次射精进行重复分析，通过消除新鲜精液中观察到的射精间变异性，有可能提高体外受精（IVF）的一致性。然而，冷冻和解冻过程会导致精子功能受损以及IVF成功率降低。在用于IVF之前，精液样本通常会进行活力筛选。低于指定活力阈值的样本可能会被丢弃。我们的目标是确定解冻后精子活力、其他可能指示精子功能的特征或一种新的输卵管结合检测方法是否与IVF成功率相关。来自16头公猪的精液在冷冻保存前冷却至15°C以便过夜运输。精液解冻后，通过显微镜记录活力，并使用计算机自动精子评估进行确认。每个样本在两到三个独立重复中进行IVF测试。采用回归和相关分析来确定精子特征之间的相互关系以及解冻后活力、精子-输卵管结合与IVF结果之间的关系。在所检查的精子特征中，精子顶体完整性与解冻后活力呈负相关（r(2)=0.64），但与IVF结果无关。与输卵管聚集体结合的精子数量与IVF多精受精率相关（r(2)=0.
