• Korean Journal of Animal Reproduction
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• v.20 no.1
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• pp.43-52
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• 1996

This study was carried out to establish the in vitro short-term culture system of developing male germ cells by purifing germ cells of various stages. The decapulated testicular cells were incubated with collagenase (lmg/ml) and try psin (2.5mg/ml) in HBSS. After separating male germ cell, the separated germ cells were stained with heamatoxylin/eosin and determined developing stages under light microscopy. The purity of pachtene spermatocytes a and round spermatid were 85%, respectively. Yield of total male germ cells was highly variable between individuals, with a mean value of 3.5 to 4.5 ${\times}$ 10$^7$ cells/testis. Viability of the cell was over 97% after separation. In DMEM medium, the optimal cell number for culture is approximately 1 x 10$^5$ cells/dish, but low cell den-sities than 1 ${\times}$ 10$^5$ cell/dish showed a decreased cell viability. Furthermore, about :36.8% of pac-hytene cells was successfully cultured for 6 days and some of cells were developed to secondary spermatids and round spermatids. Therefore, our data suggested that this culture conditions will be utilize as a feasible tools to produce tran-sgenic livestock using techniques such as intrac-ytoplasmic injection and cell fusion.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.65-65
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• 2001

본 연구는 칡소 귀세포를 공여핵으로 이용한 체세포 복제송아지 생산에 있어서 배양방법이 배발생 및 배반포 발달율에 미치는 영향과 체세포 복제란의 이식후 수태율에 미치는 영향을조사하여 복제송아지의 생산 효율을 제고하고자 실시하였다. 실험에 공시된 공여핵은 칡소 의 귀세포를 회수하여 10%FBS가 첨가된 DMEM배지에서 3-4일 동안 배양하여 monolayar Confluent 형성 후 0.25% trypsin을 처리하여 준비하였으며 공여세포는 적어도 passage가 5회 이상의 세포만을 사용하였다. 복제수정란의 생산은 18-20시간 동안 체외성숙 된 난자의 핵을 제거하고 공여핵을 주입하여 2.2kv/cm, 10$\mu\textrm{s}$의 전압으로 2회 자극함으로 융합하였으며, 융합된 난자는 5$\mu\textrm{g}$/$m\ell$ ionomycin에서 4분간, 1.9mM 6-dimethyl aminopurine에서 4시간동안 배양하여 활성화처리를 하였다. 핵이식수정란의 배양은 39$^{\circ}C$, 5%$CO_2$ incubator에서 처리구 I은 CRlaa에서 4일간 배양 후 CR2aa배지에서 배양, 처리구II는 CRlaa에 4일간 배양후 CR2aa배지에 cumulus cell과 공배양, 처리구III은 CR2aa 배지에 camulus cell과 함께 배양하였다. 수정란이식은 발정발현 7일째에 비외과적 방법으로 젖소 미경산우에 이식하였으며 이식란수는 2~4개의 핵이식된 수정란을 이식하였다. 임신진단은 45~60일 사이에 직장검사 및 초음파 진단기를 이용하여 실시하였다. 배양방법에 따른 배발생율은 처리구 I에서 92.2 %(83/90)으로 처리구II와 III의 62.4%(63/101)와 77.8%(144/185)에 비하여 높게 나타났으나 배반포 발달율은 처리구II와III에서 65.1%(41/63)와 50.0%(72/144)로 처리구 I의 30.1%(25/83)보다 높게 나타났다. 각 처리구에 따른 수정란 이식후 수태율은 처리구II와 III에서 공히 20%의 수태율을 나타낸 반면 처리구 I에서는 수태가 되지 않았다. 따라서 체세포 복제수정란의 생산에 있어서 배반포 발달율과 수태율을 높이기 위해서는 단순배양보다 공배양이 더 효과적인 것으로 사료되지만 이런 결과가 복제송아지 생산효율에 있어서도 효과적일지는 향후 더 많은 연구가 있어야 할 것으로 사료된다.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.67-67
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• 2001

전기자극은 핵이식 시 수핵난자와 공여핵의 융합을 위해 보편적으로 사용되는 방법이다(Robl, 1999). 그러나 부적절한 전기자극은 수핵난자 세포질에 해를 입히고, 이후의 배발달에 좋지 않은 영향을 준다. 본 실험은 체세포 핵이식을 \circled1 1.9㎸/cm, 20$\mu\textrm{s}$ 2회, \circled22.0㎸/cm, 20$\mu\textrm{s}$ 2회, \circled32.2㎸/cm, 10$\mu\textrm{s}$ 2회, 및 \circled41.9㎸/cm, 30$\mu\textrm{s}$ 2회의 전기자극으로 융합을 실시하여 각 자극 별 융합율과 난자의 lysis율을 비교하고, 배양 후 배반포 발생율을 조사하였다. 공여핵은 칡소의 귀 세포를 10% FBS가 첨가된 DMEM에서 39$^{\circ}C$, 5%$CO_2$의 incubator에서 배양하여 monolayer confluent형성 후 0.5% FBS가 첨가된 DMEM에서 3-4일간 배양 후 trypsin처리하여 제핵된 체외성숙 난자에 핵이식하였다. \circled1,\circled2,\circled3,\circled4의 핵이식 조건을 이용하여 공여핵의 체세포와 수핵란 세포질간의 융합을 유도한 결과, 융합율은 각각 50.7%, 48.1%, 65.5%, 및 33.3%였으며, 수핵난자의 세포질 lysis율은 39.%1, 41.7%, 22.6%,및 52.7%으로 \circled32.2㎸/cm, 10$\mu\textrm{s}$ 2회의 조건에서 융합율이 유의적으로 높았고, 수핵난자의 세포질 lysis율에 있어서도 다른 군에 비하여 낮았다 각각의 핵이식 조건별로 융합한 후 난할율 및 배반포 발생율은 각각 65.7%, 73.5%, 77.2%, 및 53.3%과 47.8%, 52.0%, 49.7%, 및 21.8%로 나타나 난할율 및 배반포 발생율에 있어서 융합조건에 따라 큰 차이는 없었으나 1.9㎸/cm, 30$\mu\textrm{s}$ 2회의 조건이 다른 조건들에 비하여 유의적으로 낮았다. 따라서, 체세포와 수핵란 세포질간의 융합율과 배반포 발생에 미치는 영향은 전압보다는 시간에 더 크게 받음을 알 수 있었으며, 이와 같은 결과에서 융합시 시간을 오래 주는 것보다 전압을 높이는 것이 수핵난자의 세포질에 상해를 줄이고 이후 배반포 발생에 유리할 것으로 사료되었다.

• Fisheries and Aquatic Sciences
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• v.15 no.2
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• pp.137-143
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• 2012

The abalone Haliotis discus hannai, is one of the economically important species in the fisheries industry. Abalone intestines are one of the by-products of its processing. To investigate its bioactive potential, abalone intestine was digested using an in vitro gastrointestinal (GI) digestion system containing pepsin, trypsin, and ${\alpha}$-chymotrypsin. The abalone intestine G1 digests (AIGIDs) produced by the GI digestion system were fractionated into AIGID I (> 100 kDa), AIGID II (10-100 kDa), and AIGID III (1-10 kDa) using an ultrafiltration membrane system. Of the three digests, AIGID II and AIGID III exhibited inhibitory effects against matrix metalloproteinase-2 and -9 (MMP-2, MMP-9) in HT1080 human fibrosarcoma cells. Both fractions potently inhibited gelatine digestion by MMP-2 and MMP-9 treated with phorbol 12-myristate 13-acetate (PMA) and migration of HT1080 cells in dose dependently. Furthermore, AIGID II and III attenuated expression of p65, a component of nuclear transcription factor kappa B. These results indicate that of the abalone intestine digests inhibit MMP-2 and MMP-9. Thus, the AIGIDs or their active components may have preventive and therapeutic potential for diseases associated with MMP-2 and MMP-9 activation in fibrosarcoma cells.

• Clinical and Experimental Reproductive Medicine
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• v.28 no.2
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• pp.131-140
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• 2001

Objective: To know the effects of xenoestrogen on spermatogenesis, we investigated the expression of cytochrome P450s enzymes (CYPscc, $CYP_{17{\alpha}}$, CYP19) and $3{\beta}$-HSD genes involved in steroidogenesis. Methods: Mouse testicular cells were prepared from 15-day-old ICR mice which had only pre-meiotic germ cells by enzyme digestion using collagenase and trypsin. Testicular cells were cultured in DMEM supplemented with FSH (0.1 IU/ml) and 10% FBS or medium with estrogen ($E_2$), bisphenol-A (BPA), octylphenol (OP; $10^{-9},\;10^{-7},\;10^{-6},\;10^{-5},\;10^{-4}M$, respectively) and aroclor 1254 (A1254) known as PCBs for 48 hours. The gene expression of cytochrome P450 enzymes were examined by semi-quantitive RT-PCR. The production of estrogen and testosterone was examined by RIA. Results: As results, expression of CYPscc mRNA was not significantly decreased, but $3{\beta}$-HSD and $CYP_{17{\alpha}}$. mRNA were significantly dose-dependent decreased. And production of testosterone and estrogen were not different except BPA and OP group ($10^{-5}M$). Conclusion: BPA, OP and A1254 might inhibit steroidogenesis by decreasing CYPscc, $3{\beta}$-HSD and $CYP_{17{\alpha}}$. mRNA expression in the mouse testis. These results suggest that BPA, OP and PCBs like as an endocrine disruptors inhibit the productions of steroidogenic enzymes and decrease the production of T and E by negative feedback mechanism. Therefore, these might disrupt steroidogenesis in Leydig cells of testis and would disturb testicular function and subsequently impair spermatogenesis.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.3
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• pp.411-416
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• 1999

Ninety-six, 35 day old, crossbred pigs, were fed either a basal diet based on com, soybean meal, fish meal and whey or one of three similar diets supplemented with either 0.5% organic acid or enzyme both alone and in combination. Neither organic acid nor enzyme produced any significant (p<0.05) improvements in daily gain or feed conversion. Organic acid, both alone and in combination with enzyme, significantly (p=0.04) decreased the pH in the lower colon. None of the treatments produced any effects on E. Coli or Lactobacillus numbers in any part of the gastrointestinal tract. Feeding enzyme increased trypsin (p=0.01), chymotrypsin (p=0.03) and amylase (p=0.08) levels in the jejunum. Chymotrypsin levels were higher (p=0.04) in the ileum of pigs fed enzyme. Serum glucose levels were lower (p=0.01) on day 14 in pigs fed enzyme either alone or in combination with acid. Under the conditions of this experiment (10% dietary whey, pigs weaned at 35 days of age), neither organic acid nor enzyme were effective in improving starter pig performance. Therefore, there would appear to be little justification for the routine inclusion of these products in diets fed to pigs weaned at 35 days or later.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.2
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• pp.270-276
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• 2008

The purpose of the present study was to investigate the effects of exogenous non-starch polysaccharides (NSP) enzymes on performance, intestinal content viscosity and digestive enzyme activities of growing pigs fed a rough rice-based diet. A total of 60 crossbred barrows with an initial body weight of 35.16 kg (SD = 0.82) were blocked by body weight and randomly assigned to two treatments with three replications. Each group was fed the diet based on rice with or without exogenous NSP enzymes (2 g/kg of diet). During the 70 days of the feeding trial, all pigs were given free access to feed and water. At the end of the feeding trial, six pigs from each treatment were randomly selected and slaughtered to collect intestinal digesta, intestinal mucosa, and pancreas. The addition of NSP enzymes improved average daily gain (p<0.05) and feed:gain (p<0.05), and decreased viscosity of digesta in the jejunum (p<0.001) and ileum (p<0.01) of pigs. The supplementation of NSP enzymes increased activities of protease (p<0.01), trypsin (p<0.01) and ${\alpha}$-amylase (p<0.05) in duodenal contents. However, digestive enzymes in the pancreas, jejunal and ileal mucosa were unaffected by the supplemental NSP enzymes (p>0.10). The results indicate that the addition of NSP enzymes to rough rice-based diets improved performance of pigs, reduced viscosity and increased digestive activity in the small intestine.

• Journal of Microbiology and Biotechnology
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• v.26 no.3
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• pp.461-468
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• 2016

In recent years, various naturally occurring defence peptides such as plectasin have attracted considerable research interest because they could serve as alternatives to antibiotics. However, the production of plectasin from natural microorganisms is still not commercially feasible because of its low expression levels and weak stability. A tandemly arrayed plectasin gene (1,002 bp) from Pseudoplectania nigrella was generated using the isoschizomer construction method, and was inserted into the pPICZαA vector and expressed in Pichia pastoris. The selected P. pastoris strain yielded 143 μg/ml recombinant plectasin (Ple) under the control of the methanol-inducible alcohol oxidase 1 (AOX1) promoter. Ple was estimated by SDS-PAGE to be 41 kDa. In vitro studies have shown that Ple efficiently inhibited the growth of several gram-positive bacteria such as Streptococcus suis and Staphylococcus aureus. S. suis is the most sensitive bacterial species to Ple, with a minimum inhibitory concentration (MIC) of 4 μg/ml. Importantly, Ple exhibited resistance to pepsin but it was quite sensitive to trypsin and maintained antimicrobial activity over a wide pH range (pH 2.0 to 10.0). P. pastoris offers an attractive system for the cost-effective production of Ple. The antimicrobial activity of Ple suggested that it could be a potential alternative to antibiotics against S. suis and S. aureus infections.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.4
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• pp.193-198
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• 2006

Many gastrointestinal muscles show electrical oscillation, so-called 'slow wave', originated from interstitial cells of Cajal (ICCs). Thus, a technique to freshly isolate the cells is indispensable to explore the electrophysiological properties of the ICCs. To apply an enzyme solution on the serosal surface for cell isolation, the intestine was inverted and 0.02% trypsin solution and 0.04% collagenase solution were applied to serosal cavity. After the enzyme treatment, mucosal layer was removed and longitudinal muscle layer was gently separated from the rest of tissue. The thin layer was stretched in the recording chamber and mounted on an inverted microscope. Using ${\beta}-escine$, perforated whole cell patch clamp technique was used. Under a microscope, the tissue showed smooth muscle cells and interstitial cells around the myenteric plexus. Under voltage clamp condition, three types of membrane potential were recorded. One group of interstitial cells, which were positive to methylene blue and CD34, showed spontaneous outward current. These cells had bipolar shape and were considered as fibroblast-like cells because of their peculiar shape and arrangement. Another group, positive to c-kit and methylene blue, showed spontaneous inward current. These cells had more rounded shape and processes and were considered as ICCs. The third, positive to c-kit and had granules containing methylene blue, showed quiet membrane potentials under the voltage-clamp mode. These cells appeared to be resident macrophages. Therefore, in the freshly isolated thin tissue preparation, methylene blue could easily identify three types of cells rather than morphological properties. Using this method, we were able to study electrical properties of fibroblast and residential macrophage as well as myenteric ICCs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.5
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• pp.406-412
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• 1992

Changes in proximate composition and protein quality were determined to find out appropriate processing conditions of the seasoned and smoked squid(Neon flying squid, Ommastrephes bartrannii). Moisture and crude protein contents were severely reduced (p<0.05), while increasing of fat and ash contents were not apparent. Seasoning and smoking contributed iii enhancing TBA value. Trypsin inhibitor(Tl) content was not increased severely after those processing steps. TI content checked in the all steps of squid processing was not correlated with the TBA value of squid in the same processing step. An improved digestibility and protein efficiency ratio(PER) were observed in the all products except with steak(mechanically soften product) in vitro enzymatic digestibilities of both raw Neon flying squid meats(mantle and arm) were significantly inferior(p<0.05) to other squid species.