Packaging of Mammalian Paternal Genome and Male Pronuclear Formation

在附睾成熟过程中和在体内穿透卵母细胞过程中，观察了大鼠精子核的DNA稳定性和巯基-二硫键状态。精子细胞和精子经醋酸酒精固定后，用吖啶橙子（AO）染色，在共聚焦显微镜下观察到红/绿色荧光的比值下降，直至附睾头。另一方面，当用rnBBr标记精子时，在精子从睾丸通过附睾的运输过程中，荧光强度逐渐降低。红/绿色AO荧光的比例在透明质酸穿透和精子解凝聚过程中增加。用mBBr标记卵黄周间隙内的精子，检测荧光。这些结果表明，在附睾精子成熟过程中，DNA对酸的稳定性似乎先于鱼精蛋白的氧化，大鼠基因组中解包装过程的初始事件开始于或仅仅开始于精子成熟过程中。 ...更多信息 用高效液相色谱-荧光检测法测定了大鼠精子穿卵和原核形成过程中卵细胞中谷胱甘肽和其他巯基的含量。还原型谷胱甘肽（GSH）含量较高，在未受精的卵母细胞和穿透卵与一个去致密的精子核比卵在原核阶段。氧化型谷胱甘肽（GSSG）含量在各实验组间无明显差异。GSSG/GSH比值在受精过程中无明显变化。虽然减少半胱氨酰甘氨酸含量没有改变实验组之间，半胱氨酰甘氨酸的氧化形式之间的精子去凝聚和原核形成增加。在受精过程中检测到低含量的胱氨酸，但在任何处理组中均未检测到半胱氨酸和γ-谷氨酰半胱氨酸。这些结果表明，大鼠卵子中的GSH含量减少之间的精子去凝聚和原核形成，可能是由于γ-谷氨酰转肽酶的活性增加。少

DNA-stability and thiol-disulfide status of rat sperm nuclei was observed during maturation in the epididymis and during penetration to the oocytes in vivo. When spermatids and spermatozoa were stained with acridine orange (AO) after fixation with acetic alcohol, the ratio of red/green fluorescence under a confocal microscope decreased until caput epididymis. On the other hand, when spermatozoa were labeled with rnBBr the fluorescence intensities gradually decreased during transportation of spermatozoa from testis through epididymis. The ratio of red/green AO fluorescence increased during penetration of zona pellucida and sperm decondensation. When spermatozoa in the perivitelline space were labeled with mBBr and examined fluorescence was detected. These results demonstrate that DNA stability against acid appears to be ahead of the oxidization of protamine during sperm maturation in the epididymis and that an initial event of the unpackaging process in rat genome begins during or just … More after zona-penetration but before penetration into the ooplasm.The contents of glutathione and other thiols in rat eggs were examined during sperm penetration and pronuclear formation by high-performance liquid chromatography with fluorescence detection. Reduced glutathione (GSH) content was higher in unfertilized oocytes and penetrated eggs with a decondensed sperm nucleus than eggs at the pronuclear stage. The content of oxidized glutathione (GSSG) was not different among experimental groups. The ratio of GSSG/GSH was not different during fertilization. Although reduced cysteinylglycine content did not changed among experimental groups, oxidized form of cysteinylglycine increased between sperm decondensation and pronuclear formation. Low contents of cystine were detected during fertilization but cysteine and gamma-glutamylcysteine were not detected in any treatment groups. These results demonstrate that GSH content in rat eggs decreases between sperm decondensation and pronuclear formation, probably due to the increased activity of gamma-glutamyl transpeptidase. Less