Centro de Investigación y Tecnología Agroalimentaria de Aragón, Zaragoza, Spain.
Theriogenology. 2011 Feb;75(3):473-81. doi: 10.1016/j.theriogenology.2010.09.015. Epub 2010 Oct 30.
The importance of understanding the sperm changes after the cryopreservation process has been emphasized in human and veterinary andrology. In previous studies, we have shown that the morphometric characteristics assessed by computer-assisted analysis following the freeze-thawing process revealed differences in terms of dimension and shape between individuals that may be related to bio-physiologic factors such as sexual maturity. The purpose of this study was to determine if there are differences associated with cryoresistance and sperm head morphometric dimensions in individuals with different sexual maturity ratings (SMRs; 12, 30 and 96 months of age). Ejaculates from nine normospermic fertile rams with different SMRs were analyzed in an attempt to quantify the morphometric dimensions and the shape of sperm heads from each group after the cryopreservation process. The mean values of sperm concentration among individuals with different SMRs were significantly different (P < 0.01). Cryopreservation substantially reduced sperm motility and plasma membrane integrity irrespective of SMR assessed, with young animals being the most affected (P < 0.01). Sperm quality at thawing for all sperm parameters evaluated was significantly higher for old individuals than for middle-aged or young individuals (P < 0.01). There were no significant differences in the sperm head dimension or shape among middle-aged and old individuals (P > 0.05). However, significant differences were detected in area, perimeter and width (lower values) and length, ellipticity and elongation (higher values) in old or middle-aged individuals compared with young individuals (P < 0.01). In conclusion, this study confirms that ram age is related to sperm morphometric dimensions, and sperm size and shape may affect spermatozoa survival, being good indicators of freezability. Therefore, the present study provides information on the morphometric maturation of ram sperm and supports the idea that the dimensions of spermatozoa may be taken as an approximate indication of its relative maturity.
人们已经强调了理解精子在冷冻保存过程后的变化的重要性，这在人类和兽医的生殖医学中尤为重要。在以前的研究中，我们已经表明，在经历了冷冻和解冻过程后，通过计算机辅助分析评估的形态特征，在个体之间存在着尺寸和形状上的差异，这些差异可能与性成熟等生物生理因素有关。本研究的目的是确定在不同性成熟评分（SMR；12、30 和 96 个月龄）的个体中，是否存在与抗冷冻能力和精子头部形态尺寸相关的差异。对来自 9 只具有不同 SMR 的正常精子生育力公羊的精液进行分析，试图定量测量每个组的精子头部形态尺寸和形状。不同 SMR 的个体之间的精子浓度平均值有显著差异（P < 0.01）。无论评估的 SMR 如何，冷冻都会大大降低精子的运动能力和质膜的完整性，而年轻动物受影响最大（P < 0.01）。对于所有评估的精子参数，解冻时的精子质量在老年个体中均显著高于中年或年轻个体（P < 0.01）。在中年和老年个体之间，精子头部的尺寸或形状没有显著差异（P > 0.05）。然而，在老年或中年个体与年轻个体之间，在面积、周长和宽度（较低值）和长度、椭圆度和伸长率（较高值）方面检测到显著差异（P < 0.01）。总之，本研究证实，公羊的年龄与精子形态尺寸有关，精子大小和形状可能会影响精子的存活率，是可冻性的良好指标。因此，本研究提供了有关公羊精子形态成熟的信息，并支持精子头的尺寸可以作为其相对成熟度的近似指示的观点。
