Mullen S F, Rosenbaum M, Critser J K
The Comparative Medicine Center and Department of Veterinary Pathobiology, The University of Missouri at Columbia, Columbia, MO 65211, USA.
Cryobiology. 2007 Jun;54(3):281-9. doi: 10.1016/j.cryobiol.2007.03.005. Epub 2007 Apr 4.
Porcine animal models are used to advance our understanding of human physiology. Current research is also directed at methods to produce transgenic pigs. Cryobanking gametes and embryos can facilitate the preservation of valuable genotypes, yet cryopreserving oocytes from pigs has proven very challenging. The current study was designed to understand the effects of anisotonic solutions on in vitro matured porcine oocytes as a first step toward designing improved cryopreservation procedures. We hypothesized that the proportion of oocytes demonstrating a normal spindle apparatus and in vitro developmental potential would be proportional to the solution osmolality. Oocytes were incubated for 10 min at 38 degrees C in various hypo- or hypertonic solutions, and an isotonic control solution and then assessed for these two parameters. Our results support the hypothesis, with an increasing proportion of spindles showing a disrupted structure as the levels of anisotonic exposure diverge from isotonic. Only about half of the oocytes maintained developmental potential after exposure to anisotonic solutions compared to untreated controls. Oocyte volume displayed a linear response to anisotonic solutions as expected, with an estimated relative osmotically inactive cell volume of 0.178. The results from this study provide initial biophysical data to characterize porcine oocytes. The results from future experiments designed to determine the membrane permeability to various cryoprotectants will allow predictive modeling of optimal cryopreservation parameters and provide a basis for designing improved cryopreservation procedures.
猪动物模型被用于增进我们对人类生理学的理解。当前的研究还致力于生产转基因猪的方法。冷冻保存配子和胚胎有助于保存有价值的基因型，但事实证明，冷冻保存猪的卵母细胞极具挑战性。本研究旨在了解非等渗溶液对体外成熟猪卵母细胞的影响，这是设计改进冷冻保存程序的第一步。我们假设，显示正常纺锤体装置和体外发育潜力的卵母细胞比例将与溶液渗透压成正比。将卵母细胞在38摄氏度下于各种低渗或高渗溶液、等渗对照溶液中孵育10分钟，然后评估这两个参数。我们的结果支持这一假设，随着非等渗暴露水平与等渗水平的差异增大，显示结构破坏的纺锤体比例增加。与未处理的对照相比，暴露于非等渗溶液后只有约一半的卵母细胞保持发育潜力。正如预期的那样，卵母细胞体积对非等渗溶液呈现线性反应，估计相对渗透惰性细胞体积为0.178。本研究结果提供了表征猪卵母细胞的初始生物物理数据。未来旨在确定各种冷冻保护剂膜通透性的实验结果将允许对最佳冷冻保存参数进行预测建模，并为设计改进的冷冻保存程序提供依据。
