ABSTRACT
OBJECTIVE: The purpose of this study was to examine the effects on in vitro development of early preimplantation mouse embryos in DMEM medium with glutamine which was controlled by different composition of glucose and pyruvate. METHODS: Four hundred and nineteen mouse 2-cell embryos were cultured in four different media with different composition of glucose and pyruvate for 96 hours. The DMEM-G contained L-glutamine for energy sources was used for control group. Group I embryos were cultured in the medium that mixed one volume of DMEM-GGP contained L-glutamine, D-glucose and sodium pyruvate for energy sources with three volume of DMEM-G, and group II embryos were cultured in the medium that mixed with same volume of DMEM-G and DMEM-GGP, and group III embryos were cultured in DMEM-GGP. RESULTS: At 24 hours, the development into >or=3-cell was significantly higher (por=8-cell was significantly higher in group I (73.1%) than control (44.2%), group II (59.6%) and III (45.8%), and also group II was significantly higher than control and group III. At 48 hours, the development into >or=morula was significantly higher in group I (90.4%) and II (86.5%) than control (73.0%). However, the development into blastocyst, in group III (15.0%) was significantly lower than control, group I and II. At 72 hours, the development into >or=expanded blastocyst was significantly higher in group I (69.2%) than group III (47.7%), and total blastocyst was significantly higher in group I (80.8%) than control (66.3%) and group III (67.3%). At 96 hours, the development into >or=hatching blastocyst was significantly higher in group I (78.8%) than control (61.5%) and group III (57.9%), and also, total blastocyst was significantly higher in group I (85.6%) than control (69.2%) and group III (72.0%). CONCLUSION: The development of early preimplantation mouse embryos cultured in group I medium that mixed one volume of DMEM-GGP with three volume of DMEM-G was better than other groups during the culture period.
Subject(s)
Animals , Mice , Blastocyst , Embryonic Structures , Glucose , Glutamine , Pyruvic Acid , SodiumABSTRACT
OBJECTIVE: The present study was undertaken to examine the effects of magnesium ion in the culture medium on the development of mouse fertilized oocytes either before or after pronuclear formation, and to investigate whether the effect of magnesium ion is related with the redistributional change of mitochondria. METHODS: Fertilized oocytes obtained from the oviducts of mice at 15 hr after hCG injection before pronuclear formation (pre-PN) or 21 hr after hCG injection after pronuclear formation (post-PN) were used. The embryos were cultured for 3 days with basic T6 medium-magnesium free and various concentrations of magnesium ion, 0.0, 0.5, 1.0, 2.0, 4.0 or 8.0 mM, respectively. After culture, the developmental stages of embryos and the number of nuclei were evaluated. To observe the effects of magnesium ion on the mitochondrial distribution, fertilized oocytes were collected at 21 hr after hCG injection and cultured for 6 hr with various concentration of magnesium ion. As a control, fertilized oocytes with pronuclei at 27 hr after hCG injection were used. RESULTS: The concentration of magnesium ion to accelerate the in vitro development of mouse fertilized oocytes appeared to be at 2.0 mM for the pre-PN and the post-PN stage embryos. In the mitochondrial redistribution patterns, the embryos cultured in 2.0 mM concentration of magnesium ion showed the highest percentage (22.6%) of distinct perinuclear clustering pattern comparing to other experimental group. CONCLUSION: The effect of magnesium ion may be related to the cytoplasmic redistribution of mitochondria. This relationship seems to connect the developmental competence of preimplantation mouse embryos in vitro. These results can suggest that higher concentration of magnesium ion (2.0 mM) than those of conventional culture medium (0.2~1.2 mM) is more suitable for in vitro culture of preimplantation mouse embryos.