PARENT SESSION
SLIDE SESSION 14: GROWTH FACTORS IN REPRODUCTIVE TISSUES
Chairs: Andrea Cupp, Barbara Vanderhyden, Wendy Ingman (Trainee)
Univ Ottawa-Lamoureaux 122
1:30 PM-3:30 PM
266
IMPROVING BOVINE EMBRYO PRODUCTION IN VITRO BY ADDING EPIDERMAL GROWTH FACTOR IN OOCYTE MATURATION MEDIUM.
Freitas, Camila1, Martins, Alicio1,2, Negrelli, Giuliano1, Carvalho, Paula Helena1, Takada, Luciana1, Brackett, Benjamin2, Abrahão, Regina1, 1 2
ABSTRACT- The aim of this study was to evaluate a putative additive embryotrophic effect of EGF when added to oocyte maturation medium at different concentrations (treatment groups I = 0 ng/ml; II = 1 ng/ml; III = 10 ng/ml; IV = 100 ng/ml) in combination with FSH ( Folltropin-V) and fetal calf serum (FCS). Oocytes were washed and selected in basic maturation medium (b-MM), i.e., Medium 199 (M-3769) plus 2.2 mg/ml sodium bicarbonate, 50 
g/ml sodium pyruvate, 50 g/ml gentamicin sulfate, and 1mg/ml polyvinyl alcohol (PVA). Then, groups of 15 oocytes were matured for 24 h in 100 l droplets of b-MM with 1000 ng/ml FSH and 15% FCS without PVA but supplemented with EGF according to the experimental design; this medium is referred to here as maturation medium (MM). In vitro fertilization (IVF) and swim-up were in m-DM. Sperm were capacitated with 20 g/ml heparin. After a 5 h insemination interval presumptive zygotes were cultured (4 l /embryo) for 67 h in c-SOF+NEA without glucose, citrate and streptomycin sulfate, but with 1.0 mM L-glutamine and penicillin (100 UI/ml). The last 5 days of culture were in fresh b-MM devoid of PVA. All media used for in vitro maturation, fertilization and culture were devoid of Hepes and oocytes and embryos were cultured under a 5% CO2 humidified atmosphere. Analyses were by ANOVA and t- test with p<0.05 as significant. Results consisted of percentages of oocytes that cleaved (C, 72h) and reached morula (M, 144h), blastocyst (B, 168h), and expanded blastocyst (EB, 192h) stages. Data for cleavage (I = 77.3, II = 83.7, III = 85.7 and IV = 80.2) and EB (I = 10.3, II = 12.8, III = 21.9 and IV = 11.5) were not different, but more (p<0.05) morula resulted after in vitro maturation (IVM) with 1 ng/ml (62.8) than 0 ng/ml (45.4) while 10 ng/ml (59.0) and 100 ng/ml (53.1) yielded similar M results to 0 ng/ml and 1 ng/ml. Higher (p<0.05) proportions of B were obtained for groups II (39.5) and III (41.9) than for groups I (28.6) and IV (29.2). In conclusion, added EGF contributed an embryotrophic effect through IVM even when FCS was present. This enhanced embryonic development demonstrated that FSH and FCS were not sufficient and lends encouragement for EGF supplementation to optimize bovine embryo production in vitro. (Supported by FAPESP, Altagenetics-VRBV and Araçafrigo, SP, Brazil.)
KEY WORDS: maturation medium, in vitro maturation, egf, fsh