• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.419-428
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• 2000

Leptin, the product of obese (ob) gene, is an adipocyte-derived satiety factor that plays a major role in the regulation of food intake, energy homeostasis, body weight, reproductive physiology and neuropeptide secretion. The present study was designed to generate transgenic mice expressing antisense mouse ob (mob) gene. Total RNA was extracted from the adipose tissues of mouse, then reverse transcription was performed. The 303 and 635 bp fragments of anti I and II cDNAs were amplified from mob cDNAs by PCR. The two mob cDNAs were reversely ligated into between adipose tissue specific aP2 promote and SV40 poly(A) site. Transgenic mice carrying two different kinds of antisense mob transgenes were generated by DNA microinjection into pronucleus. Total 14 transgenic mice were born, and the 4 and 5 founder lines of the transgenic mice with anti I and II transgenes were respectively established. Antisense mRNA expression was detected in transgenic F$_1$ mice by RT-PCR analysis. This result suggests that the transgenic mice expressing antisense mob mRNA may be useful as an animal disease model to be obesity caused by decreased amount of leptin secretion.

• Journal of Embryo Transfer
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• v.19 no.2
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• pp.165-172
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• 2004

This study was carried out to examine the effects of maturation media on in vitro maturation (IVM) of porcine immature oocytes, and on subsequent in vitro fertilization (IVF) and development (IVD). Cumulus-oocyte complexes (COCs) were collected from antral follicles of porcine ovaries collected from abattoir, and were matured in vitro in modified NCSU-37 (mNCSU-37), modified NCSU-23 (mNCSU-23), or TCM-199 supplemented with 10% porcine follicular fluid (pFF). Oocytes matured in vitro, were fertilized in vitro in modified Tris-buffered medium(mTBM) with the final motile sperm concentration of 1${\times}$105 sperm/mL, and subsequently putative embryos were developed in vitro in NCSU-23. The results are as follows. 1. In the result of IVM, the rate of germinal vesicle breakdown (GVBD) and of nuclear maturation were not significantly different among the media, though numeric value of them were slightly lower in TCM-199 than in mNCSU-37 or in mNCSU-23. 2. In the result of IVF, though the rate of sperm penetration was not significantly different among the maturation media, the percentage of oocytes with male pronucleus (MPN) of ones matured in mNCSU-37 (88.0%) was significantly higher than in TCM-199 (71.1%) (p<0.05). 3. In the result of IVD, the percentage of cleaved oocytes of ones matured in mNCSU-37 (52.3%) or in mNCSU-23 (53.7%) was significantly higher than in TCM-199 (43.1%) (p<0.05), but the rate of blastocysts at day 6 was not significantly different among the maturation media, though putative embryos from oocytes matured in mNCSU-37 or in mNCSU-23 were developed more than in TCM-199. These results suggested that mNCSU-37 or mNCSU-23 was more appropriate than TCM-199 as IVM medium for porcine immature oocytes.

• Journal of Embryo Transfer
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• v.19 no.2
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• pp.173-183
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• 2004

This study was carried out to examine the effects of epidermal growth factor (EGF) and the number of cumulus-oocyte complexes (COCs) on in vitro maturation (IVM) of porcine immature oocytes, and on subsequent in vitro fertilization (IVF) and development (IVD). COCs were collected from antral follicles of porcine ovaries collected from abattoir, and were maturated in modified NCSU-23 (mNCSU-23) with 10% pFF, 0.6 mM cysteine, 50 ${\mu}mM{\beta}-mercaptoethanol$, 1 mM dbcAMP, 10 IU/mL PMSG and 10 IU/mL hCG, which was supplemented with or without 10 ng/mL EGF and into which 50 or 15 COCs per droplet was put. Oocytes matured in vitro, were fertilized in vitro in modified Tris-buffered medium (mTBM) with the final motile sperm concentration of 1${\times}$105 sperm/mL, and subsequently putative embryos were developed in vitro in NCSU- 23. The results are as follows. 1.In the result of IVM, 10 ng/mL EGF supplement duplicated the percentage of C4 group of COCs(41% vs 81%). But the rate of germinal vesicle breakdown (GVBD) and of nuclear maturation were not significantly different between control and EGF supplemented, or between the number of COCs per culture droplet, and there was not a significant interaction between the two factors, either. 2. In the result of IVF, there was not significantly different between control and EGF supplemented, or between the number of COCs per culture droplet, or was not a significant interaction between the two factors, in the rate of sperm penetration, in the percentage of oocytes with male pronucleus (MPN), and in the rate of polyspermy. 3. In the result of IVD, there was not significantly different between control and EGF supplemented, or between the number of COCs per culture droplet in the percentage of cleaved oocytes. There was not significantly different between the number of COCs per culture droplet, but between control and EGF supplemented (p<0.01) in the percentage of blastocysts, the number of inner cell mass (ICM), trophectoderm (TC) and total cells. There was no significant interaction between the two factors anywhere. These results suggested that 10 ng/mL EGF supplement into mNCSU-23 for IVM was effective in the production of more as well as better blastocysts during IVD through increasing the number of cells in those.

• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.33-45
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• 2011

Heat shock protein 90 (Hsp90) is ATPase-directed molecular chaperon and affects survival of cancer cell. Inhibitory effect of Hsp90 by inducing cell cycle arrest and apoptosis in the cancer cell was reported. However, its role during oocyte maturation and early embryo development is very insufficient. In this study, we traced the effects of Hsp90 inhibitor, 17-allylamino-17-demethoxygeldanamycin (17-AAG), on meiotic maturation and early embryonic development in pigs. We also investigated several indicators of developmental potential, including structural integrity, gene expression (Hsp90-, cell cycle-, and apoptosis-related genes), and apoptosis, which are affected by 17-AAG. Then, we examined the roles of Hsp90 inhibitor on viability of primary cells in pigs. Porcine oocytes were cultured in the NCSU-23 medium with or without 17-AAG for 44 h. The proportion of GV arrested oocytes was significantly different between the 17-AAG treated and untreated group (78.2 vs 34.8%, p<0.05). After completion of meiotic maturation, the proportion of MII oocytes was lower in the 17-AAG treated group than in the control group (27.9 vs 71.0%, p<0.05). After IVF, the percentage of penetrated oocytes was significantly lower in the 17-AAG treated group (25.2%), resulting in lower normal pronucleus formation (2PN of 14.6%). Therefore, the inhibition of meiotic progression by Hsp90 inhibitor played a critical role in fertilization status. Porcine embryo were cultured in the PZM-3 medium with or without 17-AAG for 6 days. In result, significant differences in developmental potential were detected between the embryos that were cultured with or without 17-AAG. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) showed that the number of containing fragmented DNA at the blastocyst stage increased in the 17-AAG treated group compared with control (7.5 vs 4.4, respectively). Blastocysts that developed in the 17-AAG treated group had low structural integrity and high apoptotic nuclei than those of the untreated control, resulting in decrease the embryonic qualities of preimplantation porcine blastocysts. The mRNA expressions of cell cycle-related genes were down-regulated in the 17-AAG treated group compared with control. Also, the expression of the pro-apoptotic gene Bax increased in 17-AAG treated group, whereas expression of the anti-apoptotic gene Bel-XL decreased. However, the expression of ER stress-related genes did not changed by 17-AAG. Cultured pESF cells were treated with or without 17-AAG and used for MIT assay. The results showed that viability of pESF cells were decreased by treatment of 17-AAG ($2{\mu}M$) for 24 hr. These results indicated that 17-AAG decreased cell proliferation and increased cell death. Expression patterns Hsp90 complex genes (Hsp70 and p23), cell cycle-related genes (cdc2 and cdc25c) and apoptosis-related genes (Bax and Bcl-XL) were significantly changed by using RT-PCR analysis. The spliced form of pXbp-1 product (pXbp-1s) was detected in the tunicamycin (TM) treated cells, but it is not detected in 17-AAG treated cells. In conclusion, Hsp90 appears to play a direct role in porcine early embryo developmental competence including structural integrity of blastocysts. Also, these results indicate that Hsp90 is closely associated with cell cycle- and apoptosis-related genes expression in developing porcine embryos.

• Korean Journal of Animal Reproduction
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• v.27 no.2
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• pp.125-133
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• 2003

The present study was carried out to examine the effect of $\beta$-Mercaptoethanol ($\beta$-ME) on in vitro maturation (IVM) of porcine follicular oocytes and oxygen concentration with $\beta$-ME on in vitro development (IVD) of porcine IVM/IVF embryos. The results were summarized as follows. 1. The rates of nuclear maturation, penetrated oocytes, polyspermic oocytes, pronucleus formation and mean numbers of the penetrated sperms were not significantly different using NCSU-23 maturation media for 0, 25, 50 and 100 $\mu$M $\beta$-ME (P>0.05). 2. The rates of blastocyst formation at day 7 after in vitro fertilization were higher in oocytes matured with 25 $\mu$M $\beta$-ME (25.4$\pm$0.9%) than in those matured with 0 (14.5$\pm$1.6%), 50 (17.3$\pm$1.7%) and 100 $\mu$M (12.4$\pm$1.3%) (P<0.05). However, no differences ware found in total cell numbers of blastocyst among the treatments. 3. The rates of blastocyst formation at day 7 after in vitro fertilization were higher in the NCSU-23 Culture medium With 25 $\mu$M $\beta$-ME (23.6$\pm$2.8%) than in those Cultured With 0 (15.4$\pm$4.4%), 12.5 (17.5$\pm$2.3%) and 50 $\mu$M $\beta$-ME (18.6$\pm$2.1%) Under the 5% and 20% $O_2$ Concentrations (P<0.05). However, no differences was found in total cell numbers of blastocyst among the treatments. These results suggested that the addition of 25 $\mu$M $\beta$-ME in the IVM/IVD media were effective on the porcine embryo production. However, the rates of blastocyst formation and total cell numbers of blastocyst at day 7 of porcine IVM/IVF embryos were not significantly different in the NCSU-23 culture medium under 5% and 20% 02 concentrations.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.3
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• pp.311-318
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• 1997

Bypassing acrosome reaction and fusion process in intracytoplasmic sperm injection(ICSI), most of injected spermatozoa still contain intact acrosome contents and plasma membrane. It Is not known yet what acrosome contents and plasma membrane of spermatozoa have effect on the development of embryo. For further understanding of fertilization process after ICSI, we studied the time of pronucleus formation, disappearance and first cleavage in human zygote, and pregnancy rate in relation to acrosome reaction rate of spermatozoa after ICSI. Seventy cycles undergoing ICSI program were randomly selected. Sperm suspension from 38 cycles were treated 50% human follicular fluid(hFF) for 3 hours in order to induce acrosome reaction, others were not treated as control. Acrosome reaction in hFF treated and non-treated group was assessed by fluorescein isothiocyanate(FITC)-conjugated Arachis hypogea(PNA) and Pisum sativum agglutinin(PSA). Oocytes were classified into 'good' and 'poor' according to their morphology. After ICSI, fertilization of oocytes were assessed by detection of two pronuclei at 16 hours. The pronuclei disappearance and first cleavage of zygotes were observed at 24 hours, and then embryos were transferred to uterus after culture for 72 hours. The rate of acrosome reaction of spermatozoa in hFF treated group was significantly higher than that in control(p<0.01). Fertilization rates of good oocytes were not different both control and hFF treated group(81.3%(174/206) vs. 72.1%(102/130)). But, in poor oocytes, the fertilization rates in hFF treated group(72.1%(149/183)) were increased compared than those of control group (63.6%(98/140), p<0.01). In either good or poor oocytes, the rates of pronuclei disappearance in hFF treated-spermatozoa injected oocytes were higher than control (59.1%(103/174), 56.4%(84/149) vs. 32.4%(33/102), 37.8%(37/98), p<0.01). Also, the rates of thirst cleavage were increased in hFF treated group (31%(54/174), 24.1%(36/149)) compared than those of control group (10.8%(11/102), 13.2%(13/98), p<0.01). The pregnancy rates of hFF treated group (42.1%(16/38)) were slightly higher than control group (28.1%(9/32), p>0.05). But, the pregnancy rate of group which possessed more than one cleavaged zygote at 24 hours was higher than group which did not (45.2%(19/42) vs. 21.4%(6/28), p<0.05). From these results, the development of zygotes were faster in higher acrosome reacted sperm group than lower acrosome reacted sperm group after ICSI. Our results may be explained that acrosomal membrane and plasma membrane are easily detached from spermatozoa in acrosome reacted spermatozoa compared with acrosome intact sperm in the cytoplasm of oocyte during pronuclear formation. We conclude that the injection of acrosome reacted spermatozoa will increase the pregnancy rate as they can induce fast embryonic development in ICSI.