• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.797-804
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• 2006

The present study was undertaken to investigate the post-thawed survivability of bovine embryo depending on different dose of ethylene glycol and sucrose. Ovaries were collected at local slaughterhouse and the cumulus-oocyte-complexes aspirated from ovaries were in vitro matured, fertilized and cultured at 39°C in an atmosphere of 5% CO2 incubator. For conventional slow-freezing, d 7 or 8 expanded blastocysts were collected. Embryos were equilibrated in 1.5 M and 1.8 M ethylene glycol(EG) with 0.1 M and 0.3 M sucrose in Dulbecco's phosphate-buffered saline(D-PBS) supplemented with 0.5% bovine serum albumin. Embryos were then loaded individually into 0.25ml-straw and placed directly into cooling chamber of programmable freezer precooled to 󰠏7°C, after 2 min, the straw was seeded, maintained at 󰠏7°C for 8 min, and then cooled to 󰠏35°C at 0.3°C/min, plunged and stored in liquid nitrogen for at least 3 days. For thawing, the straw containing embryos were warmed in air for 10 sec and exposed to 37°C water for 20 sec. Straws were then removed from 37°C water. Rates of blastocyst survive and hatching were evaluated at 24 to 72 h post-warming. No difference of the survivability was shown between 1.5 M and 1.8 M EG (71 and 70%, respectively). Addition of 0.1 M sucrose to 1.5 M and 1.8 M ethylene glycol in the freezing solution did not differ significantly embryo survival (74 and 77%, respectively), whereas survival rates was higher(89%) in freezing solution contained 0.3M sucrose to 1.8M EG compared with 0.3M sucrose to 1.5M EG group(71%). However, there was no difference in the overall total cell number between the two groups (122±1.8 vs 131±1.4, respectively). In conclusion, the results suggest that 0.3 M sucrose in 1.8 M EG may be optimal condition for freezing and thawing methods with in vitro produced embryos and may be applied to on-farm conditions for embryo transfer.

• Clinical and Experimental Reproductive Medicine
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• v.30 no.3
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• pp.207-215
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• 2003

Objective: To compare the pregnancy outcomes after in vitro fertilization with intracytoplasmic sperm injection (IVF-ICSI) between obstrucvtive and non-obstrucvtive azoospermia. Methods: From January 1994 to December 2002, 524 patients with obstructive azoospermia (886 cycles) and 163 patients with non-obstructive azoospermia (277 cycles) were included in this study. Microsurgical epididymal sperm aspiration (MESA) or testicular sperm extraction (TESE) in obstructive azoospermia and TESE in non-obstructive azoospermia were perfomed to retrieve sperm, which was used for ICSI and then fertilized embryos were transferred. The results of ICSI - fertlization rate (FR), clinical pregnancy rate (CPR), clinical abortion rate (CAR) and delivery rate (DR) - were statistically analysed in obstructive versus non-obstructive azoospermia. Results: There were no differences in the number of retrieved oocytes, injected oocytes for ICSI and oocyte maturation rate. FR was significantly higher in obstructive than non-obstructive azoospermia (71.7% vs. 61.1%, p<0.001). There was no difference in CPR per embryo transfer cycle. After pregnancy was established, however, CAR was significantly higher in non-obstructive than obstructive azoospermia (25.6% vs. 12.5%, p=0.004). DR per clinical pregnancy cycle was significantly higher in obstructive than non-obstructive azoospermia (78.0% vs. 64.4%, p=0.012). In the karyotype ananlysis of abortus, abnormal karyotypes were found in 75.0% (6/8) of obstructive and 55.6% (5/9) of non-obstructive azoospermia. Conclusion: Our data show significantly higher FR in obstructive than non-obstructive azoospermia. Though there was no differrence in CPR, CAR was significantly higher in non-obstructive than obstructive azoospermia. The abortion may be related to the abnormal karyotype of embryo, but further investigations are necessary to elucidate the cause of clinical abortion in azoospermia.

• Development and Reproduction
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• v.3 no.1
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• pp.75-85
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• 1999

To investigate the origin and action mechanism of cytoplasmic factors as regulators of morphogenesis, the embryonic development, RNA synthesis and protein phosphorylation were examined in reconstituted embryos. A half of 1-cell mouse embryo with both pronuclei was electrofused with the enucleated cytoplasm of 1- or 2-cell embryos which were cultured for 24 hrs from post 20 hrs hCG in CZB with or without cycloheximide (CHX, an inhibitor of protein synthesis; P+P-CHX group), genistein (Gen, an inhibitor of tyrosine protein kinase; P+2-Gen group) and 6-dimethylaminopurine (6-DMAP, an inhibitor of serine-threonine protein kinase; P＋2-DMAP group), and co-cultured with Vero cells for 5 days. And their development, cell numbers at compaction, [5, 6-$^3$H]-uridine incorporation into RNA and the pattern of protein phosphorylation after labeling of [$^{32}$ P] orthophosphate were compared with that of the reconstituted embryos such as P+2 or P+P (control group). Embryonic development and the time of RNA synthesis in P+P-CHX were similar to those in P+P. But the time and the cell stages of embryonic compaction in P+P-CHX were similar to those in P+2. The compaction was initiated at 4-cell in P+2 and P+2-Gen, but at 8-cell in P+P and P+2-DMAP. On a two-dimensional gel electrophoresis, phosphorylation of 80KD and 110KD proteins were inhibited after 3 hrs of reconstruction in the embryo of P+2-DMAP when compared with that of P+2 and P+2-Gen. These results suggest that protein synthesis between 1- and 2-cell stage affects the timing of embryonic genome activation, and that cytoplasmic factors derived from oocyte or their modification regulates the time schedule of embryonic compaction in mouse. Also, serine-threonine protein kinase has an important role on the regulation of compaction.