Vincent C, Pruliere G, Pajot-Augy E, Campion E, Garnier V, Renard J P
INRA, Station de Physiologie Animale, Biologie du Développement, Jouy-en-Josas, France.
Cryobiology. 1990 Feb;27(1):9-23. doi: 10.1016/0011-2240(90)90048-9.
A dynamic equilibrium between globular and filamentous actin plays a crucial role in cell structure and motility. Many factors such as pH, ionic strength, temperature, and divalent cations, are known to influence this equilibrium. Some organic solvents, such as those used for the cryopreservation of cells, may also alter the dynamic equilibrium of this system. Fluorescence staining with NBD-phallacidin permits polymerized actin to be visualized in embryos and provides evidence that propanediol depolymerizes actin, whereas dimethyl sulfoxide does not. This depolymerizing effect is reversible after propanediol removal. Biochemical techniques were used to study the influence of these solvents on rabbit skeletal actin. Results obtained by sedimentation, fluorescence, DNase inhibition, electron microscopy, and viscometry analysis demonstrate that propanediol has a dual effect on actin polymers in vitro: it decreases the proportion of filamentous actin and the remaining filaments appear shorter and aggregate to form bundles. In contrast, dimethyl sulfoxide does not alter dramatically the actin polymer integrity. Propanediol is shown to exert a good cryoprotective action on rabbit embryos, while dimethyl sulfoxide does not. We suggest that the depolymerization of actin filaments by propanediol prior to cooling may facilitate the cryopreservation of one-cell rabbit embryos.
球状肌动蛋白和丝状肌动蛋白之间的动态平衡在细胞结构和运动中起着至关重要的作用。已知许多因素，如pH值、离子强度、温度和二价阳离子，都会影响这种平衡。一些有机溶剂，如用于细胞冷冻保存的溶剂，也可能改变该系统的动态平衡。用NBD-鬼笔环肽进行荧光染色可以使胚胎中的聚合肌动蛋白可视化，并提供证据表明丙二醇会使肌动蛋白解聚，而二甲基亚砜则不会。去除丙二醇后，这种解聚作用是可逆的。采用生化技术研究了这些溶剂对兔骨骼肌肌动蛋白的影响。沉降、荧光、DNase抑制、电子显微镜和粘度分析得到的结果表明，丙二醇在体外对肌动蛋白聚合物有双重作用：它降低了丝状肌动蛋白的比例，剩余的细丝显得更短并聚集形成束状。相比之下，二甲基亚砜不会显著改变肌动蛋白聚合物的完整性。结果表明，丙二醇对兔胚胎具有良好的冷冻保护作用，而二甲基亚砜则没有。我们认为，在冷却前丙二醇使肌动蛋白丝解聚可能有助于单细胞兔胚胎的冷冻保存。
