Effects of Co-Culture with Oviductal Cells, Time of Transfer into Culture Medium after Insemination on Early Development of In Vitro Fertilized Bovine Oocytes

소 체외수정란의 초기발생에 있어서 수정후 발생배지로 옮기는 시기와 난관상피세포의 영향

Early development of bovine oocytes fertilized in vitro in the medium with caffeine and heparin was examined in different culture systems. When the oocytes were transferred into culture medium 8 h after insemination, 12%(7/60) of penetrated oocytes cleaved to 4-cell stage 24 h after insemination. The proportions of oocytes cleaved to 80to 16-cell stage 48 h after insemination had also a to be higher in oocytes transferred into culture medium 8 h (29%) than 16 h(10%) or 24 h(4%) after insemination. 52% of the 4-cell embryos developed to morula and blastocyst stages when they were co-cultured with oviductal epithelia, whereas only 5% of embryos cultured without the epithelial cells(P<0.001). In another experiment, embryos were co-cultured with ampulla, isthmus or utero-tubal junction of oviducts. There are no significant differences in the proportions of embryos developed to morula and blastocyst stage.