EDTA stimulates cleavage stage bovine embryo development in culture but inhibits blastocyst development and differentiation.
Culture of bovine zygotes in medium SOFaa supplemented with 100 microM EDTA significantly increased cleavage rates during the first 72 hr of development compared to development in SOFaa. However, continued culture in the presence of EDTA for a further 72 hr (total of 6 days of culture) resulted in significantly reduced development to the morulae/blastocyst and blastocyst stages compared to culture without EDTA. Highest rates of development to the morulae/blastocyst stage (56.5%) and to the blastocyst stage (43.2%) were achieved when zygotes were cultured for 72 hr with EDTA before transfer to medium SOFaa without EDTA. Resultant blastocysts also had significantly increased blastocyst cell number and ICM cell number compared to those cultured without EDTA in the first 72 hr. EDTA was shown to inhibit glycolytic activity of the cleavage stage embryo, thereby preventing the premature stimulation of glycolysis and enhancing development. However, EDTA should not be used for the later stage embryo as the inhibition of glycolysis reduces energy production at the blastocyst stage and significantly inhibits inner cell mass development.
Gardner
D K
DK
Colorado Center for Reproductive Medicine, Englewood, CO 80110, USA. dgardner@colocrm.com
Lane
M W
MW
Lane
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D000818:Animals; D001757:Blastomeres / Q000166:cytology / Q000187:drug effects*; D002417:Cattle; D002452:Cell Count; D002454:Cell Differentiation / Q000187:drug effects; D002614:Chelating Agents / Q000494:pharmacology*; D002970:Cleavage Stage, Ovum / Q000502:physiology*; D004492:Edetic Acid / Q000494:pharmacology*; D005314:Embryonic and Fetal Development / Q000187:drug effects; D066298:In Vitro Techniques
D002614:Chelating Agents; D004492:Edetic Acid