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Demi-embryos were successfully produced by bisection of ICR mouse embryos at preimplantation stages. They were microsurgically bisected using a microsurgical blade attached to a micromanipulator after pretreatment with 0.5 % pronase in PBS for two minutes or not. Embryos with softened zona pellucida were more easily bisected and less damaged than intact embryos. The highest success rate in bisection has been achieved by selecting blastocysts (94.1 % in success rate with intact blastocysts and 100 % in success rate with zona softened blastocysts). Demi-embryos without zona pellucida were cultured in D-PBS or M-16 medium at 37deg C, 5 % CO2 in air for 72 hours for 2-cell stage embryos, 48 hours for 4-to 8-cell stage embryos, 24 hours for morula stage embryos and 6-12 hours for blastocyst stage embryos. For the in vitro culture of 2-cell stage embryos, 100 micro M 2Na-EDTA was added to the media. M-16 medium was better for the in vitro development of mouse embryos than PBS, and PBS is not considered to be suitable for long-term culture of embryos, especially at early stage of cleavage. In M-16 medium, developing rate of demi-embryos of which pair underwent development to form eublastocysts was 15.8 % at 2-cell stage, 16.8 % at 4-cell stage, 38 % at 8-cell stage, 89.6 % at morula stage and 94.4 % at blastocyst stage, respectively. The more rapid and efficient production of demi-embryos and higher viability after bisection can be expected by softening zona pellucida with pronase and by selecting morulae or blastocysts rather than embryos at early stage of cleavage.

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duplication embryonnaire mice souris embryo splitting viabilidad cultivo in vitro raton viabilite particion de embriones ...

Wolters Kluwer - United States of America

Changes in the serum immunoglobulin levels and viral antibody titers of colostrum-conferred Korean native calves during the first 12 weeks postpartum.

1989

Kim D. | Han H.R.

The changes in serum total protein and immunoglobulin levels, and BVD, IBR and PI-3 viral neutralizing antibody titers in colostrum-conferred Korean native calves during the first 12 weeks postpartum were studied. The mean concentration of total protein, total immunoglobulin, IgG, IgM and IgA in sera of 9 calves at birth were 3.8 +- 0.5g/dl, 0.27 +- 0.15mg/ml, 0.06 +- 0.08mg/ml, 0.21 +- 0.11mg/ml, and extremely low concentration, respectively. Serum total protein level reached a maximum at 20 hours after birth, total immunoglobulin, IgG and IgM levels at 24 hours, and IgA level at 28 hours, respectively. Serum IgA level reached a minimum at 4 weeks old, IgM level at 5 weeks, total immunoglobulin level at 8 weeks, and IgG level at 10 weeks, respectively. After then those levels had begun to increase, but total protein level was still decreasing at 12 weeks old. The half-lives of IgG, IgM, and IgA were 21.1 days, 4.0 days, and 2.6 days respectively. In 10 Korean native cows immediately after parturition, serum neutralizing antibody titers specific to BVD, IBR and PI-3 virus were 8.7 +- 1.5 log2, 5.7 +-1.2 log2, and 6.8 +- 1.0 log2, respectively. And colostral neutralizing antibody titers against BVD, IBR, and PI-3 virus were 10.1 +- 1.4 log2, 6.8 +- 1.3 log2, and 7.8 +- 1.7 log2, respectively. Before suckling the colostrum, SN antibody titers against BVD, IBR, and PI-3 virus were undetectable from all of 9 Korean native calves. Nevertheless SN antibody titer against BVD virus reached a maximum level (9.2 +- 0.6 log2) at 24 hours after birth, that against IBR virus (6.1 +- 1.0 log2) at 20 hours after birth, and that against PI-3 virus (6.8 +- 0.9 log2) at 32 hours after birth, respectively. In 12 weeks old calves, the SN antibodies against BVD and IBR virus were still decreasing, but that against PI-3 virus reached a minimum at 10 weeks, and increased after 12 weeks of age. The half-lives of SN antibodies against BVD, PI-3 and IBR, virus were 16.0 days, 22.6 days, and 25.5 days, respectively.

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