Instituto de Ciencia y Tecnología Animal, Universidad Politécnica de Valencia, Valencia, Spain.
Theriogenology. 2010 Mar 15;73(5):704-10. doi: 10.1016/j.theriogenology.2009.11.010. Epub 2010 Jan 6.
The aim of this work is to study the effect of the vitrification procedure on prenatal survival and on placental development at the end of gestation in rabbits (Oryctolagus cuniculus). One hundred eighty-one females were slaughtered at 72 h of gestation. Morphologically normal embryos recovered at 72 h of gestation were kept at room temperature until transfer or vitrification. Vitrified embryos (320 embryos) were transferred into a total of 24 does and fresh embryos (712 embryos) were transferred into a total of 43 does. Females were induced to ovulate 72 h before transfer when fresh embryos were transferred and 60 to 63 h before transfer when vitrified embryos were transferred. Each recipient doe received eight embryos into the left oviduct and eight embryos into the right oviduct. The number of implanted embryos was estimated by laparoscopy as number of implantation sites at Day 14 of gestation. Recipient females were slaughtered by stunning and exsanguination 25 d after the transfer, and fetuses were classified according to their status. Live fetuses and fetal and maternal placenta were weighed Pregnancy rate was defined as the total number of females having at least one live fetus at Day 28 of gestation divided by the total number of females. Prenatal survival was estimated as live fetuses at Day 28 of gestation divided by the number of transferred embryos. The pregnancy rate after transfer of vitrified embryos (92%) was similar to that achieved with fresh embryos (86%), but prenatal survival was lower for vitrified than for fresh embryos (53% vs. 34%). We did not find differences in embryo survival from 72 h to implantation. Transfer of vitrified embryos reduced fetal survival from implantation to Day 28 (57% vs. 82%). Differences in the number of live fetuses at Day 28 of gestation were mainly due to the higher fetal mortality observed soon after implantation in pregnancies resulting from the transfer of vitrified embryos. A higher percentage of decidual reactions and atrophic maternal placentas (27.5% vs. 8.3%) and also of atrophic fetal and maternal placentas (12.1% vs. 5.3%) were observed after transfer of vitrified embryos. Both treatments showed similar percentage of dead fetuses (3.3% vs. 4%). Maternal placenta of the fetuses from fresh embryos was 15% heavier than maternal placenta of fetuses from vitrified embryos.
本研究旨在探讨玻璃化冷冻程序对兔（Oryctolagus cuniculus）产前生存和妊娠末期胎盘发育的影响。181 只雌性动物于妊娠 72 小时被宰杀。在妊娠 72 小时时回收形态正常的胚胎，并在室温下保存，直至转移或玻璃化。将 320 个冷冻胚胎转移到 24 只母兔中，将 712 个新鲜胚胎转移到 43 只母兔中。当转移新鲜胚胎时，在转移前 72 小时诱导受体母兔排卵，当转移冷冻胚胎时，在转移前 60 至 63 小时诱导受体母兔排卵。每只受体母兔将 8 个胚胎移植到左侧输卵管，将 8 个胚胎移植到右侧输卵管。通过腹腔镜在妊娠第 14 天估计植入胚胎的数量，即植入部位的数量。受体母兔在移植后 25 天通过电击和放血处死，并根据其状态对胎儿进行分类。活胎和胎儿及母体胎盘称重。妊娠率定义为妊娠第 28 天至少有一只活胎的母兔总数除以母兔总数。产前存活率估计为妊娠第 28 天的活胎数除以转移胚胎数。玻璃化胚胎移植的妊娠率（92%）与新鲜胚胎相似（86%），但玻璃化胚胎的产前存活率低于新鲜胚胎（53%对 34%）。我们没有发现从 72 小时到着床期间胚胎存活率的差异。玻璃化胚胎移植后，从着床到妊娠第 28 天的胎儿存活率降低（57%对 82%）。妊娠第 28 天活胎数的差异主要是由于玻璃化胚胎移植后不久观察到的胎儿死亡率较高。玻璃化胚胎移植后，发现蜕膜反应和萎缩性母体胎盘的比例较高（27.5%对 8.3%），以及萎缩性胎儿和母体胎盘的比例也较高（12.1%对 5.3%）。两种处理方式的死胎比例相似（3.3%对 4%）。来自新鲜胚胎的胎儿的母体胎盘比来自玻璃化胚胎的胎儿的母体胎盘重 15%。
