• Asian-Australasian Journal of Animal Sciences
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• v.19 no.2
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• pp.171-175
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• 2006

The aim of this in vitro study was to test the effect of microinjection (Mi) of foreign gene into the rabbit egg pronucleus and epidermal growth factor (EGF) addition on the blastocyst rate, the cell number and the diameter of embryos, and to determine possible relationships between embryo cell number and embryo diameter. Blastocyst rate was significantly decreased in gene- Mi (G-Mi/E0) group (63.1%) comparing to intact ones (83.5%, $p_1$<0.05). The addition of EGF at 20ng/ml (G-Mi/E20) or 200 ng/ml (GMi/ E200) to gene-Mi embryos did not affect blastocyst rate (65.6 and 55.2% resp.). As a control for Mi, the eggs were microinjected with the same volume of phosphate-buffered solution (PBS-Mi) instead of the gene construct solution. Cell numbers and embryo diameters were measured from embryo images obtained on confocal laser scanning microscope. Bonferroni-modified LSD test showed that the embryo cell number in PBS-Mi group was significantly lower ($p_1$<0.05) and in gene-Mi group was tended to decrease compared with intact embryos. Embryo diameter was not different among experimental groups. No effect of EGF given at any doses both on the cell number and embryo diameter was found. A positive correlation between cell number and embryo diameter was observed in all groups of embryos. Since embryo diameter was not changed under the influence of Mi or EGF addition in this study, this seems to be more conservative characteristics of the embryo morphology. These results suggest that the pronuclear microinjection compromises developmental potential of embryos, decreasing blastocyst rate and embryo cell number, whilst embryo diameter is not affected. No effects of EGF on studied parameters were confirmed. Declined quality of Mi-derived embryos is caused by the microinjection procedure itself, rather than by the gene construct used.

• Korean Journal of Animal Reproduction
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• v.21 no.1
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• pp.9-18
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• 1997

These studies were carried out to establish an effective and practical system for commercialization of embryo production techniques by analyzing several factors influencing in vivo embryo production in Korean native cattle. In vivo embryos were flushed 226 times from 128 donors. The results obtained in studies on the factors influencing in vivo embryo production were as follows : 1. There were no significant differences in the number of total recovered, fertilized, transferable and freezable embryos among the hormone doses(FSH-P, 28∼34mg; SUPER-OV, 75IU) used for superovulation. However, over 30mg doses of FSH-P showed a slightly higher effect than others. 2. There were slight decrease in the number of fertilized, transferable and freezable embryos in 3 times repeated superovulation. But there were no significant differences among 1, 2 and 3 times repeated superovulations. 3. Age of donors did not affect the number of transferable and freezable embryos, but the number of fertilzed embryos were highest in 2∼3 years old donors and were lowest in 8∼9 years old donors(P<0.05). 4. Season had a significant effect on the production of embryos(P<0.05). the embryo production, and the number of fertilized, transferable and freezable embryos were most effective in summer and follow by spring, autumn and winter. 5. The number of transferable and freezable embryos was highest in donors flushed at 7∼8 days after estrus(P<0.05).

• Journal of Embryo Transfer
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• v.12 no.3
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• pp.301-306
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• 1997

The present study was carried out to investigate effect of FSH -P dose and energy level on normal embryo production after superovulation in Hanwoo. The results obtained were as follows ; 1. There was a significant effect of dose of FSH-P on normal embryo production in Hanwoo(P$\pm$5.9), 40(4.9i5.7), 50mg(2.2$\pm$2.6). 2. The plasma P$_4$ levels on the first treatment day were higher group( >4ng /ml) than lower group( <=4ng /ml), produced significicantly(P<0.05) higher number of normal embryos. 3. There was a significant effect of energy level on normal embryo production in Hanwoo(P$\pm$6.0), number of normal embryos were higher than TDN 70%(5.1$\pm$6.5) and TDN 130%(4.4$\pm$2.6) 4. The donor returned to normal estrus after superovulation were 44.8, 28.4 and 29.9 days by TDN 70, 100 and 130%, respectively.

• Plant Resources
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• v.5 no.2
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• pp.141-154
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• 2002

In this experiment, three kinds of mutations(ge, re, and eml )relating to the size of embryos were used to study their generation, genetic mechanism and developmental characteristics, and the interactions between embryo and endosperm were also examined. Giant embryo mutation comprises 7 kinds including the already isolated ge, and ge-2, which share an identical gene site. The SAM and the size of radicule for the ge showed little difference compared to a normal type. The number of embryo cells did not increased as much as it would affect the size of embryo. Therefore, the enlargement of embryo was due to the enlargement of scutellum that originated from the corpulence of each cell. Both F$_1$' s of re ]and odm 49 formed reduce embryos, and other combinations of hybridization showed all wild type of embryo sizes. Accordingly, the odm 49 must have an identical gene site of re 1, while odm 48 and odm 62 have different gene sites. Their shoots and radicules also shrank by the same ratio, however no sign of physical change was noticed. The size of embryo cell showed no change, while the number of cells was the half of that of wild types. The three gene sites of re represent all of them control the size of the entire embryo forming organs. The eml 1 was defined to have temperature sensibilities that the generation of endosperms was active at a high temperature while that was hampered at a low temperature.

• Journal of Embryo Transfer
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• v.26 no.3
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• pp.159-164
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• 2011

This study was performed in order to determine optimum flushing solution using the direct embryo collection (DEC). Donors, at random stages of the estrous cycle, received a CIDR. 7 days later, 200 mg FSH was treated with 40, 30, 20, 10 mg FSH levels in declining doses twice daily by intramuscular injection for 4 days. On the 3$^{rd}$ day administration of FSH, 25 mg $PGF_2{\alpha}$ was administered and CIDR was withdrawn. After FSH injections were complete, donors were artificially inseminated twice at 12 hr intervals. The donor cattle received 250 ${\mu}g$ GnRH at time of 1$^{st}$ insemination and embryos were recovered 8 days after the 1$^{st}$ insemination. Embryo collection from superovulated donors were performed to flushing by DEC and conventional method. As a results, the average number of recovered embryos were significantly higher as 19.1${\pm}$1.40 with DEC method than 12.0${\pm}$0.44 with conventional embryo collection method, respectively (p<0.05). Also, The average number of transferable embryos were significantly higher (p<0.05) as 15.8${\pm}$1.72 with DEC method than 6.9${\pm}$0.35 from conventional embryo recovery procedures. Meanwhile, number of recovered embryos and number of recovered transferable embryos following the number of flushing times until 6${dr}$ flushing were significantly higher as 8.6${\pm}$0.53 and 8.6${\pm}$0.53 from 2$^{nd}$ flushing time than other groups (p<0.05). No. of Ear. B stage embryos were significantly higher as 3.9${\pm}$0.90 and 3.9${\pm}$0.90 with 2$^{nd}$ flushing time in total collected embryos and transferable embryos (p<0.05). Com M stage embryos were significantly higher as 3.7${\pm}$1.00 in 2$^{nd}$ flushing time and as 2.2${\pm}$0.76 in 3$^{rd}$ flushing time for recovered embryos (p<0.05). In transferable embryos, Com. M stage embryos were significantly higher (p<0.05) as 3.7${\pm}$1.00 in 2$^{nd}$ flushing time and as 2.2${\pm}$0.76 in 34$^{dr}$ flushing time, also. No. of degradation embryos was significantly higher as 2.2${\pm}$0.72 in 5${rd}$ flushing time, On the other hand, degradation embryos was not observed in transferable embryos (p<0.05). In conclusion, these results suggest that DEC method should effective methods for production of in vivo embryos using less flushing solution following perform until 4$^{rd}$ flushing time than conventional embryo collecting method. Also, it might be effectively collection of transferable embryos following more less procedure times compared to conventional embryo recovery methods.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.483-489
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• 2013

The abnormal seedlings, a common physiological anomalies, emerged during embryo rescue severely restricted grape breeding. To enhance the efficiency of the seedless grape breeding by reducing the production of abnormal seedlings in the course of embryo rescue, we investigated the effects of genotype, media type, embryo style, pre-chilling on the deformity rate of the abnormal seedlings during embryo rescue. The abnormal seedlings were firstly classified into seven categories based on their morphology. Our results indicated that the emergence of abnormal seedlings was highly dependent on the female parent genotype. Polyembryony was advantageous to diminish the number of abnormal plantlets and the germination rate of embryo was 100%. We also found that pre-chilling treatment could reduce the number of abnormal plantlets and promote the embryo germination. The abnormal plantlets were reduced significantly by the addition of $ZnSO_4$ $10{\mu}mol{\cdot}L^{-1}$ or mashed-banana $500mg{\cdot}L^{-1}$ to either embryo development or germination media. Transferring the abnormal seedlings onto the suitable fresh media in 4 weeks after embryo germination provided an effective way to transform them into normal seedlings.

• Journal of Embryo Transfer
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• v.26 no.2
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• pp.117-122
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• 2011

In this study, we examined the effectiveness of in vitro fertilization of porcine immature oocytes on the embryo development of blastocysts or hatched blastocysts and the number of cells according to the in vitro fertilization conditions. In the in vitro fertilization of in vitro matured porcine oocytes, there were no significant differences between treatment groups regarding fertilization rate, blastocyst rate, and embryo development of hatched blastocysts according to the storage periods of liquid sperm of 24, 48, and 72 hours. The embryo development rate of hatched blastocysts after the fertilization according to different spermatozoa concentrations ($0.4{\times}10^5$, $1.2{\times}10^5$, and $3.6{\times}10^5$ cells/ml) showed the highest rate in the group with a spermatozoa concentration of $1.2{\times}10^5$ cells/ml; in particular, this rate was significantly higher than that in the $0.4{\times}10^5$ cells/ml group (p<0.05). The total number of blastocysts cells as well as trophectoderms (TE) that developed in each treatment group were also significantly higher in the $1.2{\times}10^5$ cells/ml group than in any other groups (p<0.05). In contrast, the embryo development rate of blastocysts according to different co-incubation periods of sperm and oocyte (1, 3, and 6 hr) was high in the 6-hour group; in particular, the rate was significantly higher than that of the I-hour group (p<0.05). Furthermore, the total number of oocytes cells and TEs that developed was significantly higher in the 6-hour group than any other group (p<0.05). In this study, the most effective treatment conditions for porcine embryo development and high cell number were found to be as follows: a sperm storage period of less than 72 hours, a spermatozoa concentration of $1.2{\times}10^5$ cells/ml, and a 6-hour co-incubation period for sperm and ooocyte.

• Journal of Embryo Transfer
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• v.15 no.1
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• pp.57-65
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• 2000

The objective of this study was to apply the multiple ovulation and embryo transfer (MOET) program practically in dairy herds. Forty five superior Holstein cows ranked in 5% according to Type-Production Index(TPI) in Korea were selected as donors. The donors were superovulated with pFSH and the embryos collected from donors were frozen and preserved. The preserved embryos and frozen Holstein embryo imported from foreign country were thawed and transferred to recipients. The results obtained were as follows; 1. The total number of ova and freezable embryos collected per donor was 6.5 and 2.8, respectively. 2. The freezable embryos were obtained more(p<0.05) when the body condition score (BCS) of donors was in range of 2.50∼3.25(4.1) than in range of 3.50∼4.00(1.9), while the total number of ova was not changed. 3. The season affected on the collected number of freezable embryos(6.1 in winter, 4.5 in fall, 1.1∼1.5 in spring and summer, P<0.05), and the total number of obtained ova were more in winter than in other seasons(P<0.05). 4. Embryos were transferred to 343 recipients and 152 cows were confirmed pregnant(44.3%). 5. The higher pregnancy was obtained (P<0.05) when embryos were transferred in summer(53.3%) than in fall(36.0%), while the pregnancy rate was not affected by the origin and developmental stage of embryos, and the parity, BCS and estrus induction of recipients. From these results, the pregnancy rate was considered to be acceptable for the embryo transfer with domestic or imported Holstein embryos, however embryo production from superior Holstein donors was unsatisfactory for application of MOET scheme.

• Journal of Embryo Transfer
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• v.33 no.4
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• pp.265-270
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• 2018

Up-to-date artificial insemination (AI) using frozen sperm consider as the most widely using technology for improvement of Korean Native Cow (Hanwoo) embryo production. However, it is time consuming, required at least 15~20 years to make more than 6 generations, and their offspring number is limited. To overcome such limitations, superovulation and in vitro fertilization have been developed. For superovulation, the number of produced embryos are not enough for commercialization and donor cows need rest period. This led to use of slaughterhouse ovary for in vitro fertilization, but it is impossible to repeat the collection from the same individual and it only can improve the genetic merits of offspring for one generation. Production of embryos using Ovum Pick-Up (OPU) technique, where oocytes can be repeatedly collected from living elite donor, might overcome these limitations. In this study, we investigated the possibility of using OPU technique from donors at different age and different session periods for mass-embryo-production. Oocytes were collected from 26 donor cows twice per week, 3 - 4 months per year, between 2013 and 2016. Results showed that, the average number of embryo produced in first year used donor was significantly higher than that in second year used donor ($3.89{\pm}2.85$ vs $3.29{\pm}2.70$), however, there was no significant difference between third year used donor ($3.51{\pm}3.32$) and other groups. Taken together, our data showed that repeated using of donor up to three years is possible for in vitro embryo mass-production. Moreover, OPU can be used as suitable embryo producing technique for livestock breed improvement.

• Journal of Embryo Transfer
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• v.2 no.1
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• pp.22-26
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• 1987

When the dairy cattle are genetically improved by embryo transfer, generation intervals can be reduced since sires are selected by their full-sister's records rather than by their daughter's records and selection intensity increases because only donor cows and sires for them are selected. In addition by embryo transfer many number of full-sisters and full-sisters are produced at the same time, resulting in the increase in the accuracy of selection.