• Clinical and Experimental Reproductive Medicine
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• v.23 no.3
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• pp.247-268
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• 1996

It has been known for a long time that gonadotropins and steroid hormones play a pivotal role in a series of reproductive biological phenomena including the maturation of ovarian follicles and oocytes, ovulation and implantation, maintenance of pregnancy and fetal growth & development, parturition and mammary development and lactation. Recent investigations, however, have elucidated that in addition to these classic hormones, multiple growth factors also are involved in these phenomena. Most growth factors in reproductive organs mediate the actions of gonadotropins and steroid hormones or synergize with them in an autocrine/paracrine manner. The insulin-like growth factor(IGF) system, which is one of the most actively investigated areas lately in the reproductive organs, has been found to have important roles in a wide gamut of reproductive phenomena. In the present communication, published literature pertaining to the intrauterine IGF system will be reviewed preceded by general information of the IGF system. The IGF family comprises of IGF-I & IGF-II ligands, two types of IGF receptors and six classes of IGF-binding proteins(IGFBPs) that are known to date. IGF-I and IGF-II peptides, which are structurally homologous to proinsulin, possess the insulin-like activity including the stimulatory effect of glucose and amino acid transport. Besides, IGFs as mitogens stimulate cell division, and also play a role in cellular differentiation and functions in a variety of cell lines. IGFs are expressed mainly in the liver and messenchymal cells, and act on almost all types of tissues in an autocrine/paracrine as well as endocrine mode. There are two types of IGF receptors. Type I IGF receptors, which are tyrosine kinase receptors having high-affinity for IGF-I and IGF-II, mediate almost all the IGF actions that are described above. Type II IGF receptors or IGF-II/mannose-6-phosphate receptors have two distinct binding sites; the IGF-II binding site exhibits a high affinity only for IGF-II. The principal role of the type II IGF receptor is to destroy IGF-II by targeting the ligand to the lysosome. IGFs in biological fluids are mostly bound to IGFBP. IGFBPs, in general, are IGF storage/carrier proteins or modulators of IGF actions; however, as for distinct roles for individual IGFBPs, only limited information is available. IGFBPs inhibit IGF actions under most in vitro situations, seemingly because affinities of IGFBPs for IGFs are greater than those of IGF receptors. How IGF is released from IGFBP to reach IGF receptors is not known; however, various IGFBP protease activities that are present in blood and interstitial fluids are believed to play an important role in the process of IGF release from the IGFBP. According to latest reports, there is evidence that under certain in vitro circumstances, IGFBP-1, -3, -5 have their own biological activities independent of the IGF. This may add another dimension of complexity of the already complicated IGF system. Messenger ribonucleic acids and proteins of the IGF family members are expressed in the uterine tissue and conceptus of the primates, rodents and farm animals to play important roles in growth and development of the uterus and fetus. Expression of the uterine IGF system is regulated by gonadal hormones and local regulatory substances with temporal and spatial specificities. Locally expressed IGFs and IGFBPs act on the uterine tissue in an autocrine/paracrine manner, or are secreted into the uterine lumen to participate in conceptus growth and development. Conceptus also expresses the IGF system beginning from the peri-implantation period. When an IGF family member is expressed in the conceptus, however, is determined by the presence or absence of maternally inherited mRNAs, genetic programming of the conceptus itself and an interaction with the maternal tissue. The site of IGF action also follows temporal (physiological status) and spatial specificities. These facts that expression of the IGF system is temporally and spatially regulated support indirectly a hypothesis that IGFs play a role in conceptus growth and development. Uterine and conceptus-derived IGFs stimulate cell division and differentiation, glucose and amino acid transport, general protein synthesis and the biosynthesis of mammotropic hormones including placental lactogen and prolactin, and also play a role in steroidogenesis. The suggested role for IGFs in conceptus growth and development has been proven by the result of IGF-I, IGF-II or IGF receptor gene disruption(targeting) of murine embryos by the homologous recombination technique. Mice carrying a null mutation for IGF-I and/or IGF-II or type I IGF receptor undergo delayed prenatal and postnatal growth and development with 30-60% normal weights at birth. Moreover, mice lacking the type I IGF receptor or IGF-I plus IGF-II die soon after birth. Intrauterine IGFBPs generally are believed to sequester IGF ligands within the uterus or to play a role of negative regulators of IGF actions by inhibiting IGF binding to cognate receptors. However, when it is taken into account that IGFBP-1 is expressed and secreted in primate uteri in amounts assessedly far exceeding those of local IGFs and that IGFBP-1 is one of the major secretory proteins of the primate decidua, the possibility that this IGFBP may have its own biological activity independent of IGF cannot be excluded. Evidently, elucidating the exact role of each IGFBP is an essential step into understanding the whole IGF system. As such, further research in this area is awaited with a lot of anticipation and attention.

• Journal of Embryo Transfer
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• v.16 no.3
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• pp.223-231
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• 2001

The success of nuclear transplantation with mammalian oocytes depends critically on the potential of oocytes activation, which mainly caused to prevent the re-accumulation of maturation promoting factor (MPF). This study was conducted to compare the effect of combined treatment of lonomycin with a Hl-histone kinase inhibitor (dimethylaminopurine, DMAP) or cdc2 kinase inhibitor (sodium pyrophosphate, SPP) on activation of bovine oocytes. In vitro matured bovine oocytes with the first polar body (PB) and dense cytoplasm were assigned to 3 experimental groups. For activation treatment, oocytcs were exposed to 5 $\mu$M lonomycin for 5 min (Group 1), and followed by 1.9 mM dimethylaminopurine (DMAP) for 3 h (Group 2) or followed by 2 mM sodium pyrophosphate (SPP) for 3 h (Group 3). The activation effects in the three treatments and the control group (untreated) were judged by the extrusion of the second PB and formation of a pronucleus (PN). Differences among groups were analysed using one-way ANOVA after arc-sine transformation of proportional data. All three treatments led to high activation rates (90% to 95%), with significant difference from the control. However, the extrusion of the second PB and the rate of PN formation differed remarkably among treatments. In Group I and 3, about 95% of the oocytes had extruded the second polar body, but one PN had formed in a higher proportion of oocytes in Group 3 than in Group 1 (90% vs. 5%). In experiment 2, the rates of cleavage and development into blastocysts in Group 1 were significantly lower than those of Group 2 and 3 (8.7% and 0% vs. 50.5% and 11.6%, and 44.6% and 7.2%, respectively, P<0.05). In experiment 3, ~80% of parthenotes in Group 1 were developed with haploid chromosomal sets. However, when ionomycin was followed immediately by DMAP (Group 2). only 20% of parthenotes were haploid. In Group 3, combined treatment with ionomycin and SPP, the appearance of abnormal chromosomal tracts was significantly (P〈0.05) reduced and the proportion of haploid parthenotes was increased to 85% (17/20) than in Group 2. These results demonstrate that SPP acted as a cdc2 kinase inhibitor and formed the haploidy in oocyte activation. Thus, the present study suggests that cdc2 kinase inhibitor, such as sodium pyrophosphate, may have an effective role in oocyte activation for the production of cloned embryos/animals by nuclear transplantation.

• Development and Reproduction
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• v.17 no.3
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• pp.207-213
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• 2013

This study was performed to investigate the effect of peroxisome proliferators activated receptor-${\gamma}$ (PPAR-${\gamma}$) ligand, pioglitazone, on production of regulated upon activation normal T-cell expressed and secreted (RANTES) and in vitro fertilization (IVF) outcome in infertile patients with endometriosis. Sixty-four infertile patients with stage III or IV endometriosis undergoing IVF were randomly allocated to the study or the control group. The long protocol of GnRH agonist (GnRH-a) was used for controlled ovarian stimulation (COS) in all patients. Patients in the study group were treated with pioglitazone at a dose of 15 mg/day orally from the starting day of GnRH-a treatment to the day of hCG injection. Blood samples were drawn for serologic assay of RANTES on the first day of GnRH-a treatment and the day of hCG injection. There were no differences between the study and control groups in patient characteristics. There were also no differences between the two groups in COS duration, and the numbers of retrieved oocytes, fertilized oocytes and embryos transferred. The clinical pregnancy rate per cycle was higher in the study group, but this difference was not statistically significant. However, embryo implantation rate was significantly higher in the study group of 12.5% compared with 8.6% in the control group (P<0.05). The serum RANTES levels after pioglitazone treatment were significantly lower than those before pioglitazone treatmen in the study group (P<0.05). Our data suggest that pioglitazone treatment can suppress RANTES production and improve the embryo implantation rate in patients with endometriosis undergoing IVF.

• Horticultural Science & Technology
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• v.29 no.4
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• pp.352-357
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• 2011

Rose seed shows low germination percentages (about 20%) because it has a high amount of substances that inhibit germination in the pericarp. We investigated the effect of orientation of achene, the day after pollination (DAP), and cold storage with or without half-cut in achene for the germination percentage in R. rugosa. Germination percentages of intact or half-cut achenes were investigated in a 16-hour photoperiod at $25^{\circ}C$ room on basal MS medium for two weeks. In germination percentage, maximum 100% was measured within one week when half-cut achenes were cultured on an orientation that the embryos facing to the light. Half-cut achenes at 90 DAP were germinated 100% regardless of cold storage. Various LED lights (red, blue, yellow, green, and white) were illuminated over the half-cut achenes to gain the effect of light color. Germination percentage of R. rugosa seeds under blue LED reached the greatest with 90% within one week of culture and these seedlings were the best with a steady growth rate. It is concluded that half-cut achenes would be an effective method to improve seed germination in R. rugosa without stratification or scarification. This system could be applied to breeding studies in rose cultivars.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.10
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• pp.1510-1516
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• 2007

These experiments were carried out to optimize the parameters of electrical activation, methods of parthenogenetic activation and embryo culture in vitro and meanwhile to isolate embryonic stem cells-like (ESCs) derived from porcine parthenogenetic blastocysts (pPBs). These results showed that, as the electric field strength increased from 1.0 to 2.7 kV/cm, the cleavage rate of parthenogenetic embryos increased gradually but the rate of oocyte lysis was significantly increased when using 2.7 kV/cm field strength. The rate of cleavage in 2.2 and 2.7 kV/cm groups was significantly increased in comparison with that of the 1.0 kV/cm group. A voltage field strength of 2.2 kV/cm DC was used to investigate blastocyst development following activation with a single pulse of 30 or $60-{\mu}sec$ pulse duration. The optimum pulse duration was 30-${\mu}sec$, with a blastocyst rate of 20.7%. Multiple pulses were inferior to a single pulse for blastocyst yield (8.0% vs. 29.9) (p<0.05). For porcine oocyte parthenogenetic activation methods, the rates of cleavage (79.0% vs. 59.8%) and blastocysts (19.4% vs. 3.4%) were significantly increased in electrical activation in contrast to chemical activation with ionomycin/6-DMAP (p<0.05). Rates of cleavage and blastocyst formation in NCSU-23 and PZM-3 embryo media were higher than those of G1.3/G2.3 serial culture media, but there was no significant difference among the three groups. The total cell number of blastocysts in PZM-3 embryo culture media containing $5{\mu}g/ml$ insulin was significantly higher than that of the control (no insulin) ($44.3{\pm}9.1$ vs. $33.9{\pm}11.7$). For isolation of PESCs-like, the rates of porcine blastocysts attached to feeder layers and ICM colony formation in Method B (nude embryo culture) were better than those in Method A (intact embryo culture).

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.5
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• pp.587-594
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• 2000

At present embryonic stem (ES) cells with confirmed pluripotential properties are only available in the mouse. Recently, we were able to isolate, culture and genetically transform primordial germ cell (PGC)-derived cells from pig embryos and demonstrate their ability to contribute to chimera development in the pig. In order to determine whether the system we developed could be used to isolate embryonic germ (EG) cells from other mammalian species, we placed isolated PGCs from cattle, goats, rabbits and rats in culture. Briefly, PGCs were isolated from fetuses of cow (day 30-50), goat (day 25), rabbit (day 15-18) and rat (day 11-12), and plated on STO feeder cells in Dulbecco's modified Eagle's medium (DMEM): Ham's F10 medium (1:1) supplemented with 0.01 mM nonessential amino acids, 2 mM L-glutamine, 0.1 mM $\beta$ - mercaptoethnol, soluble recombinant human stem cell factor (SCF; 40ng/ml), human basic fibroblast growth factor (bFGF; 20ng/ml) and human leukemia inhibitory factor (LIF; 20ng/ml). For maintenance of the cells, colonies were passed to fresh feeders every 7-10 days. In all species tested, we were able to obtain and maintain colonies with ES-like morphology. Their developmental potential was tested by alkaline phosphatase (AP) staining and in vitro differentiation assay. For genetic transformation, cells were electroporated with a construct containing the green fluorescent protein (GFP) under the control of the cytomegalovirus (CMV) promoter. GFP-expressing colonies were detected in cattle, rabbits and rats. These results suggest that PGC-derived cells from cattle, goats, rabbits and rats can be isolated, cultured, and genetically transformed, and provide the basis for analyzing their developmental potential and their possible use for the precise genetic modification of these species.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.12
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• pp.1703-1712
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• 2015

The in vitro maturation (IVM) efficiency of porcine embryos is still low because of poor oocyte quality. Although brilliant cresyl blue positive (BCB+) oocytes with low glucose-6-phosphate dehydrogenase (G6PDH) activity have shown superior quality than BCB negative (-) oocytes with high G6PDH activity, the use of a BCB staining test before IVM is still controversial. This study aimed to shed more light on the subcellular characteristics of porcine oocytes after selection using BCB staining. We assessed germinal vesicle chromatin configuration, cortical granule (CG) migration, mitochondrial distribution, the levels of acetylated lysine 9 of histone H3 (AcH3K9) and nuclear apoptosis features to investigate the correlation between G6PDH activity and these developmentally related features. A pattern of chromatin surrounding the nucleoli was seen in 53.0% of BCB+ oocytes and 77.6% of BCB+ oocytes showed peripherally distributed CGs. After IVM, 48.7% of BCB+ oocytes had a diffused mitochondrial distribution pattern. However, there were no significant differences in the levels of AcH3K9 in the nuclei of blastocysts derived from BCB+ and BCB- oocytes; at the same time, we observed a similar incidence of apoptosis in the BCB+ and control groups. Although this study indicated that G6PDH activity in porcine oocytes was correlated with several subcellular characteristics such as germinal vesicle chromatin configuration, CG migration and mitochondrial distribution, other features such as AcH3K9 level and nuclear apoptotic features were not associated with G6PDH activity and did not validate the BCB staining test. In using this test for selecting porcine oocytes, subcellular characteristics such as the AcH3K9 level and apoptotic nuclear features should also be considered. Adding histone deacetylase inhibitors or apoptosis inhibitors into the culture medium used might improve the efficiency of IVM of BCB+ oocytes.

• Korean Journal of Animal Reproduction
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• v.22 no.4
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• pp.395-403
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• 1998

In this study we determined fertilization processes and developmental ability of porcine oocytes following injection of round spermatid in the presence and absence of artificial activation. Electrical stimulation at 2 h before spermatid injection significantly increased the incidence of normal fertilization as compared to those following injection without stimulation or with stimulation immediately after injection. The incidences of two pronuclear formation and apposition were not different in oocytes between following intracytoplasmic spermatid and spermatid nucleus injection. Indirect immunocyto chemistry and laser scanning confocal microscopy study revealed that microtubuels were organized from the oocyte cortex following round spermatid injection, and this seemed to move both male and female pronuclei into the oocyte center. At 6 days following injection blastocoele formation was seen in the eggs following round spermatid (25%) and round spermatid nucleus injection (27%). However, none of oocytes developed to the blastocyst stage at 6 days following sham injection. The average cell numbers of blastocysts at 8 days following injection of spermatid and spermatid nucleus were 87 to 99. These results suggested that either round spermatid or it's nudeus can be used to produce viable embryos by injection into unfertilized oocytes in the pig.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.2
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• pp.193-201
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• 1999

In this study we determined fertilization processes and developmental ability of porcine oocytes following injection of round spermatid in the presence of artificial activation. Electrical stimulation at 3 h before spermatid injection significantly increased the incidence of normal fertilization as compared to those following injection without stimulation or with stimulation immediately after injection. The incidences of two pronuclear formation and apposition were not different in oocytes between following intracytoplasmic spermatid and spermatid nucleus injection. Indirect immunocytochemistry and laser scanning confocal microscopy study revealed that micro tubules were organized from the oocyte cortex following round spermatid injection, and this seemed to move both male and female pronuclei into the oocyte center. Paternal mitochondria which are introduced with spermatid have been observed up to 4-cell. Our study indicated that either round spermatid or it's nucleus can be used to produce viable bovine embryos by injection into unfertilized oocytes.

• Clinical and Experimental Reproductive Medicine
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• v.33 no.4
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• pp.237-243
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• 2006

Objective: The aim of this study was to evaluate the efficacy of frozen-thawed ET in poor prognosis patients such as the old age (38~44 years; OA group) and the patients who did not achieve clinical pregnancy with the first fresh ET cycle (non-pregnant patients; NP group). Methods: Laboratory and clinical data were collected from fresh and frozen-thawed ET cycles of OA and NP group. Controlled ovarian hyperstimulation (COH) and conventional insemination or ICSI, in vitro culture and ET were performed by routine procedures. Supernumerary embryos were frozen by the slow freezing method, and frozen embryos were thawed by the rapid thawing method. Embryo development, pregnancy and implantation rates were statistically analyzed by Student t-test and chi square test Results: Mean ages were similar between fresh ET ($40.0{\pm}1.8$ years, n=206) and frozen-thawed ET ($39.9{\pm}1.9$ years, n=69) cycles in OA group. However, the clinical pregnancy and implantation rate of subsequent frozen-thawed ET significantly higher than those of fresh ET cycles (29.0% and 11.2% vs. 16.5% and 7.0%, p<0.05). In NP group, there was no difference in the mean age between fresh ET ($31.2{\pm}2.3$ years, n=40) and frozen-thawed ET ($31.9{\pm}3.1$ years, n=119) in subsequent cycles. The clinical pregnancy and implantation rates were similar between the subsequent fresh ET (42.5% and 22.6%) and the frozen-thawed ET (40.3% and 18.8%). Conclusion: In old age patients, higher pregnancy rate of frozen-thawed ET compared to fresh ET cycles in this study. It may be related that better uterine environments for implantation in frozen-thawed ET cycles than that of non-physiological hormonal condition in uterus of fresh COH cycles.