Poitras P, Guay P, Vaillancourt D, Zidane N, Bigras-Poulin M
Département de Médecine, Québec.
Can J Vet Res. 1994 Oct;58(4):235-41.
The main objective of this study was to evaluate two freezing protocols and the effect of agar embedding on survival of day 6.5 equine embryos. A total of 133 embryos were used, in one group (n = 51), embryos were first embedded in agar before the freezing protocol was started. A freezing protocol to -30 degrees C or -33 degrees C was used before plunging embryos into liquid nitrogen (LN2). The embryos were thawed in water at 37 degrees C, evaluated and placed in culture. After 24 h culture, the embryos were evaluated for their morphology and development. No differences were observed between embryos plunged at -30 degrees or at -33 degrees C in LN2. The analysis of the morphology and development after thawing showed that the diameter and developmental stage at freezing correlated with embryo survival. Morula and early blastocyst stages of development were associated with better quality after freezing and thawing and had a better potential to survive after in vitro culture (p < 0.05) compared to more advanced stages. The agar failed to protect embryos from zona pellucida damage, but a tendency to prevent rupture was observed in larger embedded embryos.
本研究的主要目的是评估两种冷冻方案以及琼脂包埋对第6.5天马胚胎存活的影响。总共使用了133枚胚胎，在一组（n = 51）中，胚胎在开始冷冻方案之前先进行琼脂包埋。在将胚胎投入液氮（LN2）之前，采用了降温至-30℃或-33℃的冷冻方案。胚胎在37℃的水中解冻，进行评估并置于培养环境中。培养24小时后，对胚胎的形态和发育情况进行评估。投入-30℃或-33℃液氮中的胚胎之间未观察到差异。解冻后对形态和发育情况的分析表明，冷冻时的直径和发育阶段与胚胎存活相关。与更高级阶段相比，桑椹胚和早期囊胚发育阶段在冷冻和解冻后的质量更好，体外培养后存活的潜力更大（p < 0.05）。琼脂未能保护胚胎免受透明带损伤，但在较大的包埋胚胎中观察到有防止破裂的趋势。
