Effects of osmolarity and amino acids in a chemically defined medium on development of rat one-cell embryos

Donor and Recipient Rat Strains Affect Full-Term Development of One-Cell Zygotes Cultured to Morulae/Blastocysts

“…50: [191][192][193][194][195] 2004) chini and Bavister [1] reported that glucose and phosphate are responsible for the 2-cell block of hamster embryos cultured in 5% O 2 , 5% CO 2 , and 90% N2. Based on that observation, 1-cell stage zygotes of mice [2], rats [3][4][5], and cattle [6,7] were f o u n d t o b e c a p a b l e o f o v e r c o m i n g t h e i r developmental blocks and of developing into the blastocyst stage when cultured in phosphate-and glucose-free hamster embryo culture medium-1, HECM-1 [1]. As for rats, Miyoshi et al [5] reported that 80% of 1-cell stage zygotes cultured in modified HECM-1 medium of lowered osmolarity, named as rat 1-cell embryo culture medium (R1ECM), developed into morulae and blastocysts after 96 h. The same group [8] also demonstrated that morulae and blastocysts produced by in vitro f e r t i l i z a t i o n i n 0 .…”

Developmental Responses of 2-Cell Embryos to Oxygen Tension and Bovine Serum Albumin in Wistar Rats

“…Then, Miyoshi et al modified HECM to obtain high percentages (>90%) of embryo development in vitro. The modified medium was named rat 1-cell embryo culture medium (R1ECM) [11]. However, embryo transfer (ET) of in vitro cultured blastocysts still results in limited success [3,5,11], indicating that culture conditions for rat preimplantation embryos remain suboptimal.…”

“…In this study, to further improve embryo culture condition, the effects of oxygen tension and bovine serum albumin (BSA), two possibly important factors for embryo culture in other mammalian species [2], were examined using Wistar rats as a model, because Wistar rats have often been used for establishing the basic techniques of embryo and gamete manipulation [6,11]. Wistar rats from two breeders, Crlj:WI and Slc:Wistar, were used to examine whether or not their effects are -Note-consistent across colonies since some differences in developmental responses have been observed among rat strains [14], and these particular breeder colonies are likely to have different genetic backgrounds [16].…”

“…The composition of mR1ECM was the same as described elsewhere [11]. Medium was prepared weekly and stored at 4°C without amino acids, BSA and pyruvate, which were added immediately before medium equilibration.…”

Comparison of the Extent of DNA Damage in Rat Embryos Developed in vivo and in vitro

“…The successful development into fetuses and live-offspring of the embryos developed in vitro had been demonstrated after embryo transfer to the pseudopregnant females5). However, the implantation sites of the embryos developed in vitro and the developmental rate to full-term fetuses were decreased, compared to the embryos developed in vivo [5][6][7], and the morphological differences were also observed between the embryos developed in vivo and in vitro8 OHBOSHI, YOSHIDA and TOMOGANE medium had been equilibrated previously in the conditions described above. The 8-cell stage embryos, molurae and blastocysts that developed in vitro were collected at 48, 72 and 88h after culture, respectively.…”