Rupasri A, Shivakumar K R, Sreenath B R, Seshagiri P B
Center for Reproductive Biology and Molecular Endocrinology, Indian Institute of Science, Bangalore.
Indian J Exp Biol. 1995 Dec;33(12):911-6.
In most mammals studied, a substantial numbers of preimplantation embryos are believed to be lost in vivo. In vitro, embryos develop slowly and lose viability. Hence, there is a need to assess the extent and cause of embryonic loss both in vivo and in vitro. In this study, we assessed the quality of in vivo produced ovulation products/embryos, recovered on days 1-5 pregnancy, from naturally bred wistar rats. From day 1 pregnant rats (n = 24), 226 ovulation products were recovered which included 52% (117) unfertilized oocytes and empty zonae with/without cell debris (UFO-EZ:CD) and 48% (109) 1-cells. Flushings of day 2 rats (n = 27) contained 229 ovulation products, consisting of 70% (160) 2-cells and 30% (69) UFO-EZ:CD. Flushings of day 3 rats (n = 27) had 23% (56) 2-cells, 6% (15) 3-cells, 23% (57) 4-cells, 1% (2) 5-7 cells, 2% (5) 8-cells and 45% (112) UFO-EZ:CD, total being 247. Flushings of day 4 rats (n = 28) had 193 ovulation products comprising of one morula, 45% (86) 8-cells, 5% (9) 5-7-cells and the rest were 4-cells (2), 3-cells (2), 2-cells (1) and 48% (92) UFO-EZ:CD. Day 5 flushings (n = 27) had 202 ovulation products which included 13% (27) morulae, 17% (34) early, 36% (73) mid and 2% (5) late blastocysts; additionally, 4-cells (1), 8-cells (2) and 30% (60) UFO-EZ:CD were also recovered. On day 4, embryos (8-cells) migrated from the oviduct to the uterus. When pregnant rats (n = 25) were allowed to term, only 15 females (60%) delivered pups (128) with variable litter size (2-12). These results indicate that 56% (619/1097) of recovered rat preimplantation embryos are of expected developmental age with a mixture of asynchronously cleaving embryos. The remaining 44% (478) is comprised of 38% (417) UFO-EZ:CD and 6% (61) abnormal and developmentally retarded embryos, which are unlikely to produce viable pups at term.
在大多数已研究的哺乳动物中，大量植入前胚胎被认为会在体内丢失。在体外，胚胎发育缓慢且会丧失活力。因此，有必要评估体内和体外胚胎丢失的程度及原因。在本研究中，我们评估了从自然交配的Wistar大鼠体内在妊娠第1 - 5天回收的排卵产物/胚胎的质量。从第1天的妊娠大鼠（n = 24）中回收了226个排卵产物，其中包括52%（117个）未受精的卵母细胞以及带有/不带有细胞碎片的空透明带（UFO - EZ:CD）和48%（109个）1 - 细胞。第2天大鼠（n = 27）的冲洗液中含有229个排卵产物，其中70%（160个）为2 - 细胞，30%（69个）为UFO - EZ:CD。第3天大鼠（n = 27）的冲洗液中有23%（56个）2 - 细胞、6%（15个）3 - 细胞、23%（57个）4 - 细胞、1%（2个）5 - 7细胞、2%（5个）8 - 细胞以及45%（112个）UFO - EZ:CD，总数为247个。第4天大鼠（n = 28）的冲洗液中有193个排卵产物，包括1个桑葚胚、45%（86个）8 - 细胞、5%（9个）5 - 7细胞，其余为4 - 细胞（2个）、3 - 细胞（2个）、2 - 细胞（1个）以及48%（92个）UFO - EZ:CD。第5天的冲洗液（n = 27）中有202个排卵产物，其中包括13%（27个）桑葚胚、17%（34个）早期、36%（73个）中期和2%（5个）晚期囊胚；此外，还回收了4 - 细胞（1个）、8 - 细胞（2个）以及30%（60个）UFO - EZ:CD。在第4天，胚胎（8 - 细胞）从输卵管迁移至子宫。当妊娠大鼠（n = 25）足月分娩时，只有15只雌性大鼠（60%）产下幼崽（128只），窝仔数各不相同（2 - 12只）。这些结果表明，回收的大鼠植入前胚胎中有56%（619/1097）处于预期的发育阶段，伴有异步分裂胚胎的混合。其余44%（478个）包括38%（417个）UFO - EZ:CD以及6%（61个）异常和发育迟缓的胚胎，这些胚胎足月时不太可能产生存活的幼崽。
