• Journal of Embryo Transfer
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• v.14 no.3
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• pp.163-169
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• 1999

This study was carried out to investigate the effect of co-culture system(bovine oviduct epithelial cells; BOEC) and defined culture system(modified TALP ; mTALP) on the development of IVM-IVF embryos, and survival of in vitro produced blastocysts after freezing and thawing. Occytes from the slaugheterhous ovaries were matured and fertilized using general protocol. The results obtained were as the following: 1. Survival rates of frozen-thawed blastocysts using 10% glycerol as cryoprotectant was higher in day 7 blastocysts than in Day 8 and 9 blastocysts from co-cultrue system, but survival rate of frozen-thawed blastocysts was higher in Day 10 blastocysts than in day 8 and 9 blastocysts from defined culture system. Regardless of their age, survival rate of frozen-thawed blastocysts was significantly higher (p<0.05) in co-culture system than in defined culture system. 2. The cell number of blastocysts was significanlty higher (p<0.05) in Day 7 blasotcysts than in Day 8 and 9 blastocysts from co-cultures, but the cell number of blsstocysts was significantly higher (p<0.05) in Day 10 blastocysts than in Day 8 and 9 blastocysts from defined culture system. Regardless of the culture system, blastocysts with higher cell number showed higher survival rates after freezing and thawing.

• Korean Journal of Animal Reproduction
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• v.13 no.3
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• pp.171-178
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• 1989

These experiments were carried out to investigate the effect of a co-culture with granulosa cells on in vitro maturation, fertilization and development of bovine follicular oocytes. The bovine ovaries were obtained at a slaughter house and the follicular oocytes were recovered by aspirating the follicular fluid from the visible follicles of diameter 2-6mm. Bovine oocytes were matured in vitro for 24-26 hr and then fertilized in vitro using epididymal spermatozoa capacitated by preincubation for 2-3hr in BO solution containing BSA(5mg/ml) and caffein(25mM). Eight hours after insemination, the oocytes were cultured in a co-culture system with granulosa cells. The rates of maturation of the follicular oocytes cultured in a co-culture system with granulosa cells were 83.1%, the rate of fertilization of the follicular oocytes culture in a co-culture in a co-culture system with granulosa cells were 76.9%, respectively. No significant difference are observed between control and treatment in maturation and fertilization rates. The rates of embryos developed to 2-, 4-, 8-, 16-cell and monula stages after co-cultured with granulosa cells were 65.8, 57.9, 39.5, 34.2 and 34.2%, respectively. The value for 16-and morula stages were significantly higher (P<0.05) than those of the embryos cultured in the basic medium.

• Clinical and Experimental Reproductive Medicine
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• v.19 no.2
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• pp.133-141
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• 1992

We examined effects of co-culture with human oviduct epithelial cells (HOEC) on the development of mouse and human embryos from early embryonic· stage to late morula or blastocyst stage (LM or B). In human, embryos were transferred and pregnancy rate was investigated. The HOEC, collected from surgically removed fallopian tube, were cultured in medium-199 supplemented with 20 % fetal cord serum (FCS). The HOEC were characterized by using immunocytochemical staining with anticytokeratin antibody and then used for cultures of mouse and human embryos. Results obtained from co-culture system were as follows. Development rate of mouse embryos was improved by co-culture system at late developmental stage (p<0.025). Human supernumerary embryos remained after transfer, unsuitable for freezing because of their poor quality, were co-cultured for 72hrs. Co-culture (78.79%) or conditioned medium (78.26%) system improved the developmemt rate, significantly, in comparision with control (11.11%)(p<0.00l). Co-cultured (85.71%) human zygotes for 24hrs showed the better development rate in comparision with control (50.00%) (p<0.01). When we transferred embryos cultured with the HOEC to patients, we obtained one pregnancy. Co-cultured human zygotes for 24hrs showed the better quality and viability for the replacement in comparision with control (p<0.01). In addition, improved pregnancy rate was obtained. Our results suggest that the co-culture system can rescue early degenerating embryos by improving early development and yield a resonable number of blastocyst for the appropriate replacement. The effect provided by cultured HOEC is not species specific for the development of embryos and it can be used to overcome in vitro blocks for the development. And also the co-culture system offers the possibility to freeze embryos at blastocyst stage which is more sucessful stage for the freezing. The HOEC monolayer may provide some stimulus via specific factor, which is unknown, to the development of embryos. Our results showed that the co-culture system with HOEC can be an alternative to conventional culture system.

• Journal of Biomedical Engineering Research
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• v.29 no.2
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• pp.159-163
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• 2008

The goal of this study is to investigate the effect and potential of three-dimensional Co-culture of BMSCs (bone marrow stromal Cells) and NP (nucleus pulposus) Cells on the differentiation of BMSCs into NP-like Cells. The NP Cells and BMSCs were isolated and cultured from New Zealand White rabbits. The isolated NP Cells and BMSCs were prepared in different alginate beads. Those two types of beads were separated by a track-etched membrane of $3\;{\mu}m$ pore in a 6-well culture plate. No growth factors were used. In addition to these, NP and BMSC were cultured in the beads independently for control. The number of Cells in Co-culturing system was half of those in two control groups. Proliferation and production of glycosaminoglycan (GAG) were evaluated along with histological observation. The GAG production rate(GAG contents/Cell) of Co-cultured BMSCs were much higher than that of BMSCs cultured alone. The total amounts of GAG produced by BMSCs in Co-culturing system were larger than those produced by BMSCs in control group and were comparable with those produced by NP alone even the number of each Cell was half of BMSCs in Co-culturing system. This study showed the potential of differentiation of BMSCs into NP-like Cells through three-dimensional Co-culture system even without any chemical agents.

• Journal of Embryo Transfer
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• v.29 no.1
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• pp.1-5
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• 2014

Recent 2 decades, including in vitro maturation (IVM), assisted reproductive technologies (ARTs) achieved noteworthy development. However the efficiency of ARTs with in vitro matured oocytes is still lower than that with in vivo oocytes. To overcome those limitations, many researchers attempted to adapt co-culture system during IVM and consequently maturation efficiency has been increased. The beneficial effects of applying co-culture system is contemplated base on communication and interaction between various somatic cells and oocytes, achievement of paracrine factors, and spatial effects of extracellular matrix (ECM) from somatic cell surface. The understanding of co-culture system can provide some information to narrow the gap between in vitro and in vivo. Here we will review current studies about issues for understanding cu-culture system with various somatic cells to improve in vitro maturation microenvironment and provide bird view and strategies for further studies.

• Journal of Embryo Transfer
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• v.29 no.3
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• pp.207-219
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• 2014

Three-dimensional (3D) culture system is useful technique for study of in vivo environment and it was used various experiments. This study was investigated to establish of embryo co-culture system and changes of PAs activity in 3D cultured endometrial cells of pigs. In results, growth of stromal cells into gel matrix were detected only with endometrial and myometrial cells. The most rapid growth of stromal cells were confirmed in $2.5{\times}10^5cells/ml$ and gel matrix containing 15% FBS. Expression of urokinase-PA (uPA) after treatment of hCG (0.5, 1.0, 1.5 and 2.0 IU/ml) were higher than without hCG, but, there are not significant difference among the treatment. On the other hand, expression of uPA after treatment of $IL-1{\beta}$ (0.1, 1, 10 and 100 ng/ml) were higher than without $IL-1{\beta}$, but, there are not significant difference. Expression of uPA after treatment of estrogen (0.2, 2, 20 and 200 ng/ml) were not difference, but PA activity was significantly decreased (p<0.05). Blastocyst was producing in PZM-3 medium containing FBS and endometrial cells were grown in PZM-3 medium. When embryos development with cultured endometrial cells, cleavage rates were not significant difference and blastocyst were not produced in co-culture with stromal cells and 3D culture system. 3D culture system had similar activity to in vivo tissue and these features are very useful for study of in vivo physiology. Nevertheless 3D culture system was not proper in embryo co-culture system. Therefore, we suggest that 3D culture system with embryo co-culture need continuous research.

• Korean Journal of Animal Reproduction
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• v.17 no.1
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• pp.69-74
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• 1993

This study was investigated to examine the effect of conditioned medium from bovine oviductal cell(BOEC) in the co-culture system with BOEC on in vitro development of in vitro produced bovine embryos. Oocyte-cumulus complexes were cultured for 24 hrs in TCM-199 supplemented with 10% fetal calf serum, 1$\mu\textrm{g}$/ml FSH and 21U hCG, 1$\mu\textrm{g}$/ml oestradiol-17$\beta$ at 39$^{\circ}C$ under 5% CO2 in air. In vitro fertilization was performed with epididymal sperm and heparin (10$\mu\textrm{g}$/ml, 15min.) or caffeine(2.5mM)-treated spermatozoa. Oocytes were incubated with 1$\times$106 spermatozoa/ml for 18 hrs and then cultured in various culture system for 7 days. The development rates of 16-cell or blastocyst stages were recorded on 4, 7 days, respectively, after incubating. The proportions ofembryonic development into molulae and blastocysts were higher in cumulus cell co-culture(23.4%) and BOEC co-culture(34.3%) than in M199-FCS(6.1%). Similarily, the development rates into molulae and blastocysts were significantly higher in BOEC-conditioned medium than those in M199-FCS. Therefore, it is suggested that BOEC co-culture and BOEC conditioned medium increase significantly the development of in vitro produced bovine embryos in in vitro system.

• Applied Chemistry for Engineering
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• v.27 no.1
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• pp.1-9
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• 2016

The co-culture system of microalgae and bacteria enables simultaneous removal of BOD and nutrients in a single reactor if the pair of microorganisms is symbiotic. In this case, nutrients are converted to biomass constituents of microalgae. This review highlights the importance and recent researches using symbiotic co-culture system of microalgae and bacteria in wastewater treatment, focusing on the removal of nitrogen and phosphorus. During wastewater treatment, the microalgae produces molecular oxygen through photosynthesis, which can be used as an electron acceptor by aerobic bacteria to degrade organic pollutants. The released $CO_2$ during the bacterial mineralization can then be consumed by microalgae as a carbon source in photosynthesis. Microalgae and bacteria in the co-culture system could cooperate or compete each other for resources. In the context of wastewater treatment, positive relationships are prerequisite to accomplish the sustainable removal of nutrients. Therefore, the selection of compatible species is very important if the co-culture has to be utilized in wastewater treatment.

• Journal of Embryo Transfer
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• v.11 no.3
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• pp.201-210
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• 1996

This experiment was carried out to evaluate the effect of early mouse embryonic development in vitro by co-culture with bovine and porcine oviductal epithelial cells (BOEC and POEC). The 2-cell embryos were collected from the oviducts of the superovulated and mated cultured in D-PBS /15% FCS at 48 hours after hCG injection. The in vitro developmental rate of blastocyst formation in the embryos were examined under the fllowing treatments; 1) TCM 199 added 15% HCS, 2) Ham's F-10 added 15% HCS, 3) MediCult IVF medium, 4) TCM 199 added 15% HCS + BOEC, 5) TCM 199 added 15% HCS + POEC, 6) Ham's F40 added 15% HCS + BOEC, 7) Ham's F-10 added 15% HCS + POEC,8) MediCult IVF medium + BOEC, 9) MediCult IVF medium + POEC. For a comparative study of in vitro development for 96 hours after hCG injection, were cultured with oviductal epithelial cell and media only. The obtained results were 2-cell embryos developed to the blastocyst stage in TCM 199, Ham's F-10 and MediCult IVF medium at the rates of 84.4,83.2 and 81.6%. respectively. The higher developmental rates(91~97%) of blastocyst formation was appeared when the embryos were co-cultured with a monolayer of bovine or porcine oviductal epithelial cells in TCM 199 or Ham's F-10 and MediCult IVF media. No significant difference in developmental rates was shown between bovine and porcine oviductal epithelial cells but significant difference in co-culture system in comparison between media only system and co-cultures. In conclusions, oviductal epithelial cells, BOEC and POEC, when co-culture with mouse early embryos improved the rates of development, blastocyst and hatching. Therefore, it is suggested that co-culture system using oviductal epithelial cells improve early embryonic developtnent in mouse.

• Korean Journal of Agricultural Science
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• v.45 no.4
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• pp.715-723
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• 2018

The present study was done to investigate the effect of co-culturing muscle satellite cells (MSCs) and intramuscular preadipocytes (IPs) on the differentiation of adipocytes and muscle cells isolated from Korean native cattle. MSCs and IPs were single-cultured in 10% fetal bovine serum/Dulbecco's modified Eagles medium (FBS/DMEM) for 48 h followed by culturing in 5% FBS/DMEM as the growth media. Then, the growth media was replaced by differentiation media composed of 2% FBS/DMEM without any additives for the single- or co-culture of muscle cells and intramuscular adipocytes to induce the differentiation of both cell types. Cell differentiation was measured by morphological investigation and cytosolic enzyme analysis of glycerol-3-phosphate dehydrogenase (GPDH) for the adipocytes and creatine kinase (CK) for the muscle cells. In the morphological test, the presence of muscle cells did not stimulate adipocyte differentiation showing more differentiation of the adipocytes in the single-culture compared to the co-culture condition. However, the differentiation of muscle cells was promoted by adipocytes in the co-culture. The results of the enzymatic analysis were highly associated with the morphological results with a statistically higher GPDH activity (p < 0.05) appearing in the single-culture than in the co-culture, whereas the opposite was true for the CK activity of the muscle cells (p < 0.05). By manipulating in vivo the milieu using a co-culture, we could detect the difference in the rate of cell differentiation and suggest that a co-culture system is a more reliable and precise technique compared to a single-culture. Further studies on various co-culture trials including supplementation of differentiating substances, gene expression analysis, etc. should be done to obtain practical and fundamental data.