Dos Santos-Neto P C, Cuadro F, Barrera N, Crispo M, Menchaca A
Instituto de Reproducción Animal Uruguay, Fundación IRAUy, Camino Cruz Del Sur, 2250, Montevideo, Uruguay; Programa de Posgrado, Facultad de Veterinaria, Universidad de La República, Av. Lasplaces, 1550, Montevideo, Uruguay.
Instituto de Reproducción Animal Uruguay, Fundación IRAUy, Camino Cruz Del Sur, 2250, Montevideo, Uruguay.
Cryobiology. 2017 Oct;78:8-14. doi: 10.1016/j.cryobiol.2017.08.002. Epub 2017 Aug 10.
The objective was to evaluate pregnancy outcomes and birth rate of in vivo derived vs. in vitro produced ovine embryos submitted to different cryopreservation methods. A total of 197 in vivo and 240 in vitro produced embryos were cryopreserved either by conventional freezing, or by vitrification with Cryotop or Spatula MVD methods on Day 6 after insemination/fertilization. After thawing/warming and transfer, embryo survival rate on Day 30 of gestation was affected by the source of the embryos (in vivo 53.3%, in vitro 20.8%; P < 0.05) and by the method of cryopreservation (conventional freezing 26.5%, Cryotop 52.0%, Spatula MVD 22.2%; P < 0.05). For in vivo derived embryos, survival rate after embryo transfer was 45.6% for conventional freezing, 67.1% for Cryotop, and 40.4% for Spatula MVD. For in vitro produced embryos, survival rate was 7.3% for conventional freezing, 38.7% for Cryotop, and 11.4% for Spatula MVD. Fetal loss from Day 30 to birth showed a tendency to be greater for in vitro (15.0%) rather than for in vivo produced embryos (5.7%), and was not affected by the cryopreservation method. Gestation length, weight at birth and lamb survival rate after birth were not affected by the source of the embryo, the cryopreservation method or stage of development (average: 150.5 ± 1.8 days; 4232.8 ± 102.8 g; 85.4%; respectively). This study demonstrates that embryo survival and birth rate of both in vivo and in vitro produced ovine embryos are improved by vitrification with the minimum volume Cryotop method.
目的是评估经不同冷冻保存方法处理的体内来源与体外生产的绵羊胚胎的妊娠结局和出生率。在授精/受精后第6天，共有197个体内胚胎和240个体外生产的胚胎通过传统冷冻法，或使用Cryotop或刮铲MVD方法进行玻璃化冷冻保存。解冻/复温并移植后，妊娠第30天的胚胎存活率受胚胎来源（体内53.3%，体外20.8%；P<0.05）和冷冻保存方法（传统冷冻26.5%，Cryotop 52.0%，刮铲MVD 22.2%；P<0.05）影响。对于体内来源的胚胎，胚胎移植后的存活率传统冷冻法为45.6%，Cryotop法为67.1%，刮铲MVD法为40.4%。对于体外生产的胚胎，传统冷冻法存活率为7.3%，Cryotop法为38.7%，刮铲MVD法为11.4%。从第30天到出生的胎儿丢失率体外生产的胚胎（15.0%）有高于体内生产的胚胎（5.7%）的趋势，且不受冷冻保存方法影响。妊娠期长度、出生体重和出生后羔羊存活率不受胚胎来源、冷冻保存方法或发育阶段影响（平均值分别为：150.5±1.8天；4232.8±102.8克；85.4%）。本研究表明，采用最小体积Cryotop法进行玻璃化冷冻可提高体内和体外生产的绵羊胚胎的存活率和出生率。
