Date of Award

1991

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

First Advisor

Joseph D. Roussel

Abstract

The objective of this experiment was to compare in vitro development of bovine embryos obtained from superovulation and in vitro fertilization (IVF) in two unique monolayer co-culture systems, bovine fetal spleen cell monolayers (BFS) and chick embryo fibroblast monolayers (CEF). To test the possible harmful effects of these co-culture systems, 225 murine morula-stage embryos were cultured for 72 hours with these monolayers. The percentage of hatched embryos was 62.7% in culture medium alone, 76% in BFS and 57.3% in CEF. BFS and CEF did not induce any detectable harmful effect on these developing murine embryos. When 60 transferable morula-stage bovine embryos, which were obtained from superovulation, were cultured for 72 hours, the percentage of embryos that hatched in vitro was 45% in culture medium alone, 75% in BFS and 83.4% in CEF. Finally, the developmental capabilities of cleaved IVF bovine embryos were compared among four treatments: cumulus cells monolayers (Treatment A), BFS (Treatment B), CEF (Treatment C) and a control in tissue culture medium (TCM-199) alone (Treatment D). When 200 cleaved embryos obtained from heifers were cultured for more than 10 days, the percentage of development to the blastocyst stage was 32%, 18%, 18% and 26% for Treatments A, B, C and D, respectively. The percentage of hatched blastocysts was 18%, 8%, 6% and 0% for Treatments A, B, C and D, respectively. More IVF embryos developed to hatched blastocysts from the cumulus cell monolayer treatment and the BFS treatment than from the control in TCM-199 alone. When 100 cleaved embryos obtained from cows were cultured, the percentage of development to the blastocyst stage was 32%, 20%, 36% and 16% for Treatments A, B, C and D, respectively. The percentage of hatched blastocysts was 20%, 8%, 28% and 0% for Treatments A, B, C and D, respectively. These results showed that CEF treatment was as effective as cumulus cell monolayer treatment in the development rate of IVF embryos of cows to the hatched blastocyst stage. No IVF embryos from either heifers or cows in the control treatment of TCM-199 alone developed to hatched blastocysts. The overall results showed that co-culturing in BFS and CEF can be useful for superovulated or IVF bovine embryos.

Pages

151

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