1989 Fiscal Year Final Research Report Summary
Role of cells cocultured with in vitro fertilized bovine embryos on their development in vitro.
| Project/Area Number |
63560269
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
畜産学(含草地学)
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| Research Institution | University of Kagoshima |
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Principal Investigator |
GOTO Kazufumi Kagoshima University Department of Animal Science Assistant Professor, 農学部, 助手 (30162142)
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| Project Period (FY) |
1988 – 1989
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| Keywords | Cattle / In-vitro Fertilization / In-vitro Culture / Cumulus Cells / Coculture / Chromosome / Freezing / Pregnancy Rate |
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| Research Abstract |
We have succeeded to obtain bovine blastocysts from totally in-vitro technique in 1987. The critical point of this technique was the use of coculture system, namely bovine blastocysts were cocultured with cumulus cells. However, the percentage of embryos ( in-vitro fertilized ) developed to blastocysts was low ( 10-35 % ).
The purpose of this study was to obtain calves from the transfers of blastocysts produced by totally in-vitro technique and to clarify the role of cocultured cells on the development of bovine embryos.
1. Embryos cocultured with cumulus cells developed to molura (29.8%) and blastocysts (26.6%) stages, respectively, while embryos cultured in medium alone failed to develop beyond morula ( 0-1.5% ) and blastocyst (0%) stages. As the number of cumulus cells cocultured with embryos increases, higher % of blastocysts was obtained. Embryos cocultured with bovine oviductal cells and uterine cells also developed to blastocysts. The types of cells ( cumulus, oviductal or uterine ) did not affect on the rates of development to blastocyst stage under our culture condition.
2. Blastocysts obtained from totally in-vitro technique tended to have more chromosomal abnormalities than those of in-vivo developed.
3. Total of 15 calves ( including 4 premature calves ) were obtained from 1988 to 1989. Four calves were obtained from the transfers of fresh blastocysts and 9 calves were from the transfers of frozen-thawed blastocysts. Two calves were obtained from the bisected blastocysts. Ten males and 5 females were delivered. All calves appeared to be completely normal. Pregnancy rate of the transfers of fresh blastocysts was 50-60%, while that of frozen-thawed blastocysts was 10-50%.
The results of this study indicates that some chemical factors secreted from the cocultured cells may enhance the development of bovine embryos fertilized in-vitro. Normal calves can be obtained from the transfers of blastocysts produced by totally in-vitro technique.
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