Résumé
Background: Many autocrine and paracrine elements that are produced within follicular niche have been the focus of much in vitro maturation [IVM] research. The present study was carried out to compare retinoic acid [RA] and basic fibroblast growth factor [bFGF] efficacy on IVM of mouse oocytes, and their further dual consumption to reach an optimal protocol
Materials and Methods: In this experimental study, germinal vesicle [GV] oocytes obtained from two-months-old NMRI mice were randomly divided into control, sham and three experimental groups. The basic culture medium was alpha-MEM supplemented with 10% fetal bovine serum [FBS], 50 mg/l streptomycin, 60 mg/l penicillin and 10 ng/ ml epidermal growth factors. Each of the experimental groups received one of the following treatments: RA [2 microM], bFGF [20 ng/ml] or combination of RA and bFGF with the indicated concentrations. After 24 hours, capacitated spermatozoa were added to in vitro matured oocytes. Five hours later, the oocytes were cultured in fresh droplets of M2 medium for 24 hours and assessed for cleavage to the two-cells stage
Results: As compared with the control group, the rate of maturation was significantly increased in the RA [P<0.001] and bFGF+RA [P<0.02] groups with 58 +/- 10 and 57 +/- 3.46, respectively. The rate of maturation was significant in the RA [P<0.02] and bFGF+RA [P<0.03] groups, in comparison with the bFGF group. The bFGF+RA group had higher rate [83 +/- 1.52] of two-cells development, than control [33 +/- 1, P<0.001]
Conclusion: Our findings showed beneficial effects of 2 micro M RA and 20 ng/ml bFGF combination on mouse oocyte IVM
Résumé
Background: This study aimed to investigate the maturation and fertilization rates of immature mouse oocytes using Embryonic Stem Cell Conditioned Medium [ESCM]
Methods: Germinal Vesicle [GV] stage oocytes were observed in 120 NMRI mice, aged 4-6 weeks. GV oocytes with or without cumulus cells were subjected to IVM in either ESCM, Embryonic Stem Cell Growth Medium [ESGM], or alpha-minimum essential medium [alpha-MEM]. After recording the Metaphase II [MII] oocyte maturation rate, the oocytes were fertilized in vitro. The fertilization success rate was recorded after 24 hr. The embryos were maintained in potassium Simplex Optimization Medium [KSOM] for 96 hr and allowed to grow until the blastocyst stage. After recording developmental competence, they were transferred into the uteri of pseudopregnant mice and their birth rates were recorded
Results: No significant difference existed between the maturation rates in alpha-MEM [68.18%] and ESCM [64.67%; p>0.05], whereas this rate was significantly higher for both alpha-MEM and ESCM compared to ESGM [32.22%; p<0.05]. A significant difference in IVF success rate existed for oocytes grown in alpha-MEM [69.44%], ESCM [61.53%], and ESGM [0%]. A significantly higher developmental competence was observed at the blastocyst stage for oocytes grown in alpha-MEM [51.2%] compared to ESCM [35%; p<0.05]. 17 days after embryo transfer into the uteri of pseudopregnant mice, there was a nonsignficant [p>0.05], similar birth rate between alpha-MEM and ESCM [47 vs. 40%]
Conclusion: ESCM is an effective medium for preantral follicle growth, oocyte maturation, and subsequent embryo development