Do V H, Walton S, Catt S, Taylor-Robinson A W
School of Health, Medical and Applied Sciences, Central Queensland University, Rockhampton, Australia. National Key Laboratory of Animal Cell Technology, National Institute of Animal Sciences, Hanoi, Vietnam.
Australian Reproductive Technologies, Mt Chalmers, Australia.
Cryo Letters. 2018 May/Jun;39(3):219-226.
Modifications to in vitro maturation (IVM) media are made to improve rates of blastocyst formation and quality of mammalian embryos. Embryo quality is an important factor in the viability of embryos following cryopreservation. Salubrinal is a specific inhibitor of endoplasmic reticulum stress-induced apoptosis in eukaryotic cells. Here, it was added to IVM medium in an attempt to increase blastocyst formation and to enhance embryo quality in cattle.
To assess the effect on blastocyst formation and cryotolerance of the supplementation of salubrinal to bovine IVM medium.
Cumulus-oocyte complexes (COCs) collected from slaughterhouse ovaries were assigned randomly to two groups, either cultured in IVM medium that was supplemented with 400 mM salubrinal (treated, 262 COCs) or that was not supplemented (control, 263 COCs). All oocytes of the matured COCs were fertilized in vitro with sperm from the same proven bull and cultured for 6-7 d. At the time of blastocyst collection, expanded blastocysts were chosen for cryopreservation, while early, hatching and hatched blastocysts and those of poor quality were not used. There were 83 expanded blastocysts classified to be of good quality in both the control and salubrinal-treated groups that were subjected to vitrification. After 5 to 10 months of cold storage, the embryos were warmed and cultured in vitro for 24 h to assess the survival rate and for 48 h to assess the hatching rate.
The blastocyst developmental rate in the salubrinal-treated group was similar to that in the control group, 61.5% compared with 62.7% (P > 0.05). The survival rate of blastocysts after vitrification was also similar, at or very close to 100%. In addition, there was no statistically significant difference in the hatching rate of expanded blastocysts derived from the COCs cultured with (treated) and without (control) addition of salubrinal to the IVM medium (91.6% compared with 85.5%; P > 0.05).
Supplementation of salubrinal to the IVM medium neither improved nor reduced rates of bovine blastocyst formation and of embryo cryotolerance as determined by post-warming viability.
对体外成熟（IVM）培养基进行改良，以提高哺乳动物胚胎的囊胚形成率和质量。胚胎质量是冷冻保存后胚胎存活能力的一个重要因素。Salubrinal是真核细胞内质网应激诱导凋亡的一种特异性抑制剂。在此，将其添加到IVM培养基中，试图提高牛的囊胚形成率并改善胚胎质量。
评估向牛IVM培养基中添加Salubrinal对囊胚形成和耐冻性的影响。
从屠宰场卵巢收集的卵丘-卵母细胞复合体（COCs）随机分为两组，分别在添加400 mM Salubrinal的IVM培养基中培养（处理组，262个COCs）或未添加的培养基中培养（对照组，263个COCs）。所有成熟COCs的卵母细胞均与同一头经证实的公牛的精子进行体外受精，并培养6 - 7天。在收集囊胚时，选择扩张囊胚进行冷冻保存，而早期、孵化中和已孵化的囊胚以及质量差的囊胚则不使用。对照组和Salubrinal处理组各有83个分类为高质量的扩张囊胚进行玻璃化冷冻。冷藏5至10个月后，将胚胎解冻并在体外培养24小时以评估存活率，培养48小时以评估孵化率。
Salubrinal处理组的囊胚发育率与对照组相似，分别为61.5%和62.7%（P > 0.05）。玻璃化冷冻后囊胚的存活率也相似，达到或非常接近100%。此外，在IVM培养基中添加（处理组）和未添加（对照组）Salubrinal培养的COCs所获得的扩张囊胚的孵化率在统计学上没有显著差异（分别为91.6%和85.5%；P > 0.05）。
向IVM培养基中添加Salubrinal，既未提高也未降低牛囊胚形成率以及由解冻后活力所确定的胚胎耐冻性。
