玻璃化冷冻对猪体外成熟卵母细胞染色体与纺锤体的影响

通过冷冻体外培养成熟的猪MⅡ卵母细胞,分析了不同冷冻方案对卵母细胞形态、纺锤体微管和染色体形态结构影响,探讨冷冻前后猪卵母细胞超微结构的变化,以及玻璃化冷冻对卵母细胞后续发育能力的影响。     

卵巢玻璃化冷冻保存研究进展

卵巢玻璃化冷冻是一种操作简单、冷冻效果好的卵巢组织冷冻降温技术,对动物繁殖能力保存、物种保护、生物多样性保存,以及动物胚胎工程和人类临床医学研究与应用等具有重要意义。卵巢组织冷冻保存较卵母细胞冷冻保存,具有明显的优点。在冷冻保护剂的选择、冷冻材料、冷冻平衡及冷冻方法上都有其特殊之处。卵巢组织冷冻保存技术已在人类医学临床上发挥其应用价值。     

小鼠卵母细胞SSV法冷冻保存技术的研究

试验用2种前处理液(10%EG和10%EG 10%DMSO)和4种玻璃化冷冻液(EFS30、EFS40、EDFS30和EDFS40)对小鼠卵母细胞进行玻璃化(SSV)法冷冻保存,研究小鼠卵母细胞冷冻后的发育潜力。结果表明:小鼠未成熟卵母细胞形态正常率最高可达92.3%,成熟率达57.2%;成熟卵母细胞形态正常率最高可达91.5%。     

Cell Ultrastructure of Kiwifruit (Actinidia chinensis) Shoot Tips During Cryopreservation

The changes in the cell ultrastructure of in vitro cultured shoot tips from dwarf genotype of kiwifruit (Actinidia chinensis Ganmi 5) during cryopreservation were investigated. Shoot tips were preserved in liquid nitrogen using vitrification, and the cell ultrastructure was examined using transmission electron microscopy (TEM). The regular ultrastructure of the cell wall, cell membrane and nucleus of shoot tips could be damaged during the freezing and thawing associated with preservation using liquid nitrogen. The cell plasmolysis was increased and freezing tolerance was improved after preculturing and dehydrating in a preservation and vitrification solution (PVS2 ) (30% glycerol (Gly)+ 15% ethylene glycol (EG)+ 15% dimethylsulfoxide (DMSO) + 0.4 mol L-1 sucrose). The structure of some cells with low degree of injury and reversible damage was similar to that of the control and they could undergo normal cell division and differentiation. Besides, they could recover automatically and regenerate after their reculture.     

苹果砧木试管苗发生玻璃化的因素及预防

对苹果砧术试管苗继代培养过程中形成玻璃苗的可能因素，如瓶内湿度、琼脂浓度、细胞分裂素浓度进行比较试验，观察玻璃苗的形成及变化情况．结果表明：瓶内湿度过大，琼脂浓度略低，细胞分裂素浓度过高，都易引起玻璃化现象，而改变这些因素，可以有效地预防和缓解玻璃苗的发生．     

牛胚胎玻璃化超快速冷冻一步法移植试验

应用 30 %乙二醇 0 .3mol/ L 蔗糖 - m- PBS液 (VS1)、30 %乙二醇 0 .3m ol/ L 蔗糖 5 %葡聚糖 (T- 5 0 0 ) - m-PBS液 (VS2 )、30 %乙二醇 0 .3mol/ L蔗糖 10 %葡聚糖 (T- 5 0 0 ) - m- PBS液 (VS3)玻璃化超快速冷冻奶牛胚胎 ,一步法移植。结果显示 ,VS1、VS2、VS3组玻璃化超快速冷冻奶牛胚胎解冻后的形态正常率分别为 10 0 % (2 0 / 2 0 )、95 %(19/ 2 0 )和 5 5 .6 % (5 / 9) ;培养存活率分别为 70 % (14 / 2 0 )、75 % (15 / 2 0 )和 2 2 .2 % (2 / 9) ;囊胚孵化率分别为 0、2 0 % (4/2 0 )和 0。VS1、VS2组玻璃化冷冻奶牛胚胎解冻后的形态正常率极显著地高于 VS3组 (P<0 .0 1) ;VS1、VS2组玻璃化冷冻奶牛胚胎解冻后的培养存活率分别显著 (P<0 .0 5 )和极显著 (P<0 .0 1)地高于 VS3组。 VS1组冷冻的胚胎经一步法移植了 5头 (1枚 /头 ) ,未获得妊娠 (0 / 5 ) ;VS2组冷冻的胚胎用一步法移植了 10头 (1枚 /头 ) ,结果获得 2头妊娠(2 / 10 ) ,并产下 2头正常犊牛。     

新鲜、玻璃化冷冻牛卵母细胞体外受精囊胚全基因组甲基化模式初探

旨在初步分析新鲜及玻璃化冷冻牛卵母细胞体外受精囊胚全基因组甲基化模式。本研究采用单细胞全基因组甲基化测序技术(scWGMS)检测新鲜、玻璃化冷冻牛卵母细胞体外受精囊胚全基因组甲基化水平和差异甲基化区域(DMR),探讨两者之间DNA甲基化水平上的差异。结果表明,新鲜卵母细胞体外受精囊胚的整体甲基化水平显著高于玻璃化冷冻卵母细胞体外受精囊胚的整体甲基化水平(P<0.05)。采用基因本体分析(GO)和相关信号通路(KEGG)对143个DMRs分析,发现生物学过程主要显著富集在新陈代谢、生长发育、细胞定位、细胞刺激反应等,通路主要富集在生长发育、核酸结合及组蛋白乙酰化上,并筛选出几个与之相关的候选基因(FARP2、PI4KA、FAM3D、NCOR2、ZNF827等)。本研究初步发现,玻璃化冷冻牛卵母细胞体外受精囊胚的全基因组甲基化水平显著降低,且DMR区域主要集中在ATP结合、生长发育及组蛋白乙酰化,为提高玻璃化冷冻卵母细胞体外受精囊胚质量提供信息参考。     

A single injection of corifollitropin alfa supplemented with human chorionic gonadotropin increases follicular recruitment and transferable embryos in the rabbit

Superovulation protocols are designed to achieve maximum embryo yields. Nevertheless, ovarian response control and the quality of obtained embryos are still a challenge. On the other hand, to save the superovulated embryos until their subsequent use, it is usual to cryopreserve them, so it is also crucial to assess their cryotolerance. The aim of this study was to compare the efficacy of a single injection of corifollitropin alfa (FSH‐CTP) alone or supplemented with human chorionic gonadotropin (hCG) and to determine the impact of this stimulation on in vitro and in vivo development of fresh or devitrified embryos. Our outcomes showed that ovulation rate and recovered embryos were significantly increased when hCG was used. In vitro development of fresh and devitrified embryos and survival at birth were not significantly affected by superstimulation treatment. Results of this study suggest that a single injection of long‐acting FSH‐CTP supplemented with hCG can be effectively used in rabbits to elicit an increase in ovulation rate and number of recovered embryos. Furthermore, we demonstrated that hCG supplementation had no negative effects in embryo cryosurvival and development, showing similar survival rate at birth than FSH‐CTP alone group.