Beneficial effects of culturing rabbit zygotes to blastocysts in 5% oxygen and 10% carbon dioxide.
Zygotes were collected from superovulated Dutch-belted rabbits 19 h after injection of LH and insemination. Oocytes that appeared to be unfertilized were discarded. The zygotes were distributed equally within each donor female across all culture treatments. Culture dishes contained 500 microliters of macromolecule-free RD medium consisting of equal parts of RPMI 1640 and low glucose Dulbecco's modified Eagle's medium. Embryos were cultured at 39 degrees C in several gas combinations of N2 plus the following: (1) 1% O2:10% CO2; (2) 5% O2:10% CO2; and (3) 20% O2:10% CO2. The control (4) was 95% air:5% CO2. The experiment was replicated with embryos from 11 donors providing 295 usable zygotes. After 84 h of culture, the percentages of blastocysts formed in treatments 1 to 4, respectively, were 13, 86, 82 and 59 (P < 0.01). The corresponding mean cell counts, including all cleaved embryos cultured (but not degenerate ones), were 55, 183, 118 and 68 (P < 0.01). These results indicate that 10% CO2 combined with 5% O2 is a more effective gas phase for culturing rabbit zygotes in a synthetic medium than is the commonly used 5% CO2, and that 5% O2 is superior to either 1% or 20% O2.
Farrell
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Department of Animal Science, Cornell University, Ithaca, New York 14853-4801, USA.
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D000818:Animals; D001755:Blastocyst; D002245:Carbon Dioxide; D002470:Cell Survival; D002478:Cells, Cultured; D003470:Culture Media; D005314:Embryonic and Fetal Development; D010100:Oxygen; D011817:Rabbits; D015053:Zygote
D003470:Culture Media; D002245:Carbon Dioxide; D010100:Oxygen