• Clinical and Experimental Reproductive Medicine
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• v.24 no.1
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• pp.43-49
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• 1997

The objective of this study is to determine developmental pattern and cell allocation to the ICM and TE in haploid and diploid of embryos following parthenogenetic activation and in vitro fertilization. The incidence of development to blastocyst was lower in the combined treatments of ethanol stimulation and cytochalasin B as compared to the control. However, the combined ethanol stimulation and cytochalasin B treatment (diploid) accelerated development to the blastocyst as compared to the ethanol treatment alone (haploid). Significantly reduction in the average number of total cells and ICM was observed in the parthenotes alone as compared to fetilized embryos, but those of combined ethanol stimulation and cytochalasin B treatment embryos were significantly increased as compared to ethanol alone embryos. These results suggested that the ploidy affects preimplantation developmental patters and cell allocation to the ICM and TE in the porcine.

• Journal of Embryo Transfer
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• v.19 no.3
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• pp.229-237
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• 2004

The main objective of this study was to examine the effects of serum and gonadotropins supplement during in vitro maturation(IVM) of bovine oocytes on nuclear maturation and embryo development, and we also examine the cell number. 1 . The first polar body(PB) extrusion rates of Korean native cow(KNC) oocytes matured in medium with FBS or gonadotropins were similar among treatment groups. The development rate to the blastocyst stage was significantly higher in the group of both supplement FBS and gonadotropins(26.0％) than in the group of non-supplement(9.9％) and gonadotropins (12.0％). The numbers of inner cell mass (ICM) and trophectoderm (TE) cells and total cell numbers of blastocysts were highest in the group of both supplement FBS and gonadotropins, and the number of ICM cells was increased by FBS supplementation (p<0.05). 2. The PB extrusion rates of KNC oocytes matured in medium with FBS in the different duration of IVM was significantly higher in the 0-18hr(63.1％) and in the 9-18hr(63.4％) group than in the 0-9hr.(37.4％) group (p<0.05). The embryo development rates did not differ among treatment groups. The numbers of TE cells and total cell numbers of blastocysts were similar among treatment groups, but the number of ICM cells of the 0-18h. group were significantly higher than the other treatment groups (p<0.05). The results indicate that although TCM199 alone can support bovine oocyte maturation and development to the blastocyst stage, a high quality of blastocysts can be produced from oocytes matured in medium containing serum and gonadotropins.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.68-68
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• 2001

Blastocyst formation, consisting of the inner cell mass (ICM) and trophectoderm (TE), is the first differentiation process during embryonic development in mammals. It has been hypothesized that the proportion of ICM to TE in the blastocyst may be crucial for subsequent developmental competence of early embryos, which it may be expressed as a sensitive indicator for evaluating in vitro systems. In this study ICM/total cell ratio of nuclear transfer (NT) embryos was compared with IVF-derived and in vivo embryos. Somatic cell nuclei obtained from a fetus at Day 40 of gestation were transferred into the enucleated oocyte and then cultured in NCSU 23 medium for 6 days as previously described (Koo et al., Biol. Reprod. 2000; 63:986-992). ICM and TE cells of blastocysts were determined by using a differential staining method (Han et al., Biol. Reprod. 1999; 60:1110-1113). Development rate (9.8$\pm$2.5%, 23/225) to the blastocyst stage of NT embryos was lower than IVF embryos (23.8$\pm$2.7%, 53/223). Thus, a difference was detected in the in vitro developmental rate to blastocyst stage between NT and IVF-derived embryos (P<0.05). In the next experiment, we investigated ICM and TE nuclei to assess the quality of blastocysts that produced by NT, IVF and in vivo, respectively. NT blastocysts (27.6$\pm$8.3) showed a smaller total cell number than IVF-derived (42.6$\pm$17.4) and in vivo embryos (283.9$\pm$103.5) (P<0.05). Ratios of ICM/total cells in NT, IVF and in vivo blastocysts were 15.1$\pm$ 18.6% (n=56), 12.3$\pm$9.2% (n=57) and 30.4$\pm$6.8% (n=40), respectively. Individual blastocysts for the ratio of ICM/total cells were assigned to 3 groups (I; <20%, II; 20 to 40% and III;>40%). As the results, most in vivo blastocysts (97.5%, 39/40) were distributed into group II while most NT (78.6%, 44/56) and IVF-derived blastocysts (82.5%, 47/57) were allocated to group I. Thus, our data show that NT or IVF-derived embryos have aberrant morphology during early development in vitro systems, suggesting that these anomalies may result in developmental failures of the NT embryos to term.

• Clinical and Experimental Reproductive Medicine
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• v.23 no.3
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• pp.319-326
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• 1996

The objective of this study was to investigate correlation between the morphology by microscopic assessments of surplus blastocysts produced in human IVF program and their cell number obtained by differential labelling method. For these experiments, 76 surplus human blastocysts were obtained from 36 patients on day 5 after IVF, the embryos were classified to early (ErB), early expanding (EEB), middle expanding (MEB), expanded blastocyst (EdB) according to their blastocoel expansion and zona thickness. When the ovum size and zona thickness of the classified blastocysts were measured using micrometer, although the embryos were produced in the same culture condition, there were significant variances in ovum size ($148.8 217.6{\mu}m$) and zona thickness ($1.2-14.4{\mu}m$). Total blastomere cell number counted after hoechst staining was increased by two to three fold during the transition period from ErB ($39.1{\pm}3.6$) to EdB ($(89.6{\pm}3.3)$) stage on day 5 after IVF. ICM ($11.9{\pm}1.8-22.2{\pm}4.3$) and TE ($24.5{\pm}3.6-70.0{\pm}7.7$) cell numbers using differential labelling were also showed the increased pattern according to the developmental level. Especially, EdB which showed poor ICM morphologically also indicated the low ICM cell number after differential labelling. This demonstrated that there is good correlation between the morphological assessment and the cell number. The count of ICM and TE nuclei using differential labelling can be used as an important criterion, if it is accompanied with morphological assessments, in selecting the better embryos for improving the pregnancy rates in human blastocyst transfer program.

• Journal of Embryo Transfer
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• v.27 no.4
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• pp.259-264
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• 2012

Solution of glycerol, ethylene glycol, sucrose, dextrose (GESD) and cryotop methods were carried out to investigate the survivability on vitrification of embryos. Embryos cultured in vitro were vitrified by GESD of 10 or 8 step and cryotop methods of 6 step, from cryopreservation step to frozen-thawed and culture step. Survival rate and ICM, TE cells of embryos were investigated after frozen-thawed 24 h. As a results, cryotop method was significantly (p<0.05) higher ($85.76{\pm}5.3$ vs. $66.71{\pm}2.4$, $44.80{\pm}2.1%$) than GESD 10 or 8 step methods on survivability. Also, In ICM cell number, cryotop method was significantly (p<0.05) higher to $45.67{\pm}4.7$ cells than GESD 8 step method. TE cell number was significantly (p<0.05) highest to $111.00{\pm}11.0$ cells in cryotop method. On the other hand, survival rate, TE and total cell number were all the significantly (p<0.05) high, except ICM in GESD 10 step method between GESD 10 step method and GESD 8 step method. In conclusion cryotop method was to be most effective, but it is considered necessary to study vitrification method for step-by-step freezing and thawing process.

• Korean Journal of Agricultural Science
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• v.40 no.4
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• pp.353-358
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• 2013

To demonstrate that follistatin treatment enhances the efficiency of nuclear transfer (SCNT), cell allocation and preimplantational development were determined in bovine SCNT embryos in the present study. Treatment of activated SCNT embryos with 10 ng/ml follistatin significantly increased the proportion of blastocyst development compared to untreated SCNT embryos. In addition, an increase in trophectoderm (TE) cell numbers and relatively higher proportion of TE cells to total cells were observed, but the number of inner cell mass (ICM) cell and total cell numbers were not changed (P < 0.05). No significant effect of other doses of follistatin was observed for the above endpoints. However, treatment with 1 and 10 ng/ml follistatin reduced the proportion of nuclear transfer blastocysts with an ICM ratio of > 60% relative to untreated nuclear transfer blastocysts at Day 7. No significant effect of follistatin treatment on proportions of nuclear transfer blastocysts with ICM ratio of 20-40% or 40-60% was observed. Taken together, these results suggested that follistatin can be used to increase developmental competence of SCNT embryos in terms of cell allocation, particularly TE cells, during preimplantation stages, subsequently enhancing placentation and birth of live offspring.

• Reproductive and Developmental Biology
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• v.28 no.1
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• pp.29-36
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• 2004

The objective of this study was to investigate the effects of amino acid supplementation of oocyte maturation medium on 1st polar body(PB) extrusion, embryo development and blastocsyt cell number. In experiment 1, Cumulus oocyte complexes(COCs) were matured in in vitro maturation(IVM) medium supplemented with 1, 2, or 4-fold of 10 $\mu$l/ml MEM non-essential amino acid(NEAA) and 20 Park, $\mu$ l/ml BME essential amino acid(EAA). The PB extrusion rate of oocytes matured in 1-fold amino acid group was significantly higher than that matured in medium without amino acid (p＜0.05), but it was decreased by the increase of the dosage of amino acid. There were no difference in the percentage of embryos reaching 2-cell, 8-cell and blastocyst in all treatments. The number of trophectoderm(TE) cells and total cell number of blastocysts were highest in 2-fold amino acid group, and the number of inner cell mass(ICM) cells was increased by the increase of the dosage of amino acid. In experiment 2, COCs were matured in IVM medium with 1, 5, or 10 mg/ml lactalbumin hydrolysate(LAH). The PB extrusion rate of oocytes matured in medium with 5 mg LAH was significantly higher than that matured in medium with 1 mg LAH (p＜0.05). The development rate to the blastocyst stage was significantly higher in non-supplement and 1 mg LAH group than in 5 mg and 10 mg LAH group (p＜0.05). The number of TE cells and total cell number did not differ among treatment groups, but the number of ICM cells was increased by the increase of LAH supplement. These results suggested that the supplement of certain group of amino acid in IVM medium effective on the quality of blastocyst, and further studies will be accompany with the search of new sources of amino acid used for the use of in vitro embryo production.

• Reproductive and Developmental Biology
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• v.31 no.1
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• pp.35-41
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• 2007

This study was conducted to examine the effects of energy substrates in different conoentration of carbohydrates in the human oviduct and uterus on the in vitro development of mouse 2-cell embryos. Two-cell embryos were collected from ICR female mice at $46{\sim}50\;hr$ after 5 IU hCG injection and cultured in three different media [control: 0 mM, Guoup A: glucose (G) 0.5 mM + pyruvate (P) 0.32 mM + lactate (L) 10.5 mM, Group B: G 3.15 mM + P 0.1 mM + L 5.83 mM] for 72 hr. Rates of morula formation of group A (72.3%) and B (56.6%) were significantly higher higher (p<0.05) than that of control (34.9%) at 24 hr. However, blastocyst rate was significantly higher (p<0.05) in control (51.8%) than group A (39.8%) and B (28.9%) at hr. At 72 hr, no differences were found in the number of zona-intact, zona-escape and total blastocysts among groups. Mean and ICM cell numbers were significantly higher (p<0.05) in group A (78.0, 13.4) and B (64.4, 11.8) than control (53.1, 5.7), respectively, The percent of ICM were significantly higher (p<0.05) in group A (22.9%) and B (23.7%) than control (14.2%). No differences were round in the TE cell numbers ($34.1{\sim}45.1$). The ICM:TE ratio was significantly higher $34.1{\sim}45.1$ in control (1:6.0) than group A (1:3.4) and B (1:3.4). This study shows that energy substrates added to culture media especially, the oviductal level of carbohydrates increase the developmental capacity of 2-cell mouse embryos.

• Clinical and Experimental Reproductive Medicine
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• v.23 no.1
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• pp.25-32
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• 1996

This work has been carried out to examine the number of Total, ICM and TE cells of F1 mouse blastcysts at day 4 after IVF by differential labelling of the nuclei with polynucleotide-specific fluorochromes and to obtain a fundamental information of preimplantation mouse embryo development. Blastocysts produced by superovulated B6CBA F1(C57BL/${\times}$CBA) eggs were inseminated with $1{\times}10^6$spermatozoa/ml and cultured in M16 medium at $37^{\circ}C$, 5% $CO_2$ incubator for 95hrs. Blastocysts were classified as early, middle, expanded and hatching stage according to the developmental morphology; blastocoel expansion and zona thickness. The results obtained in these experiments were summarized as follows; 1) The development rate of blastocysts at 95hrs after IVF was 86.7% and classified blastocysts to early, middle, expanded and hatching were 16.3%, 18.9%, 10.5% and 40.9%, respectively. 2) The numbers of total blastomere using bisbenzimide in the classified blastocysts to early, middle, expanded and hatching were 35.6${\pm}$1O.4, 49.4${\pm}$8.6, 60.8${\pm}$1O.7 and 62.7${\pm}$13.9, respectively. 3) In ICM and TE cell number by using differential labelling with polynucleotide-specific fluorochrome in the classified blastocysts to early, middle, expanded and hatching; ICM numbers were 9.6${\pm}$3.0, 13.6${\pm}$3.9, 16.0${\pm}$3.3 and 19.5${\pm}$4.6, respectively and TE cell numbers were 30.6${\pm}$5.1, 39.9${\pm}$5.8, 42.2${\pm}$8.1 and 43.7${\pm}$11.1, respectively. These results showed the same increase pattern according to development advance level. Also, when compared with the results of total count were obtained between bisbenzimide only and differential labelling, both of them showed the same increase pattern according to development level and at the same time their cell numbers were almost the same. So, rapid and simple cell count method using differential labelling can be used for the examination of later preimplantation development or as an indicator of embryo quality according to the variables of culture conditions.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.20-20
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• 2001

It has been reported that cloning cattle is inefficient. One of the problems was placental abnormality, finally resulting in fetal mortality after transfer of nuclear transfer (NT) bovine embryos. This study was focused on the allocations of embryonic cells to the inner cell mass (ICM) or to the trophectoderm(TE) in NT bovine blastocysts. Somatic cells were derived from a Day 45 fetus of gestation, individually transferred into enucleated oocytes and developed to the blastocyst stage in vitro. Differential staining was used to assess the qualify of blastocysts derived from NT, IVF and in vivo. Development rate of NT embryos to blastocysts (25.0%, 41/164) was similar to that of IVF embryos (28.7%, 49/171). The total cell number of NT blastocysts (101.3$\pm$45.9) was not different compared with that of IVF embryos (107.9$\pm$34.2, P>0.05), but was lower than in vivo embryos (122.5$\pm$21.6, P<0.05). Ratio of ICM/total cells was higher in NT embryos (51.6$\pm$ 18.6%) than in IVF and in vivo embryos (42.3$\pm$ 15.3% and 34.9$\pm$8.9%, respectively) (P<0.05). Most IVF (56.8%, 25/44) and in vivo blastocysts(80.8%, 21/26) was distributed in the proportion of ICM/total cells ranging from 20 to 40% group. However, most NT blastocysts was biased in the 40-60%(34.1%, 15/44) and >60% (31.8%, 14/44) groups. Our findings suggest that placental abnormalities or early fetal losses in the present cloning system may be due to aberrant allocation of NT embryos to the ICM cells.