The production of transgenic animals using somatic cell nuclear transfer (SCNT) has been widely described. A critical problem in the production of transgenic animals is the uncontrolled constitutive expression of the foreign gene which occasionally results in serious physiological disorders in the transgenic animal. In this study, we designed three different expression vectors that express the hEPO gene. hEPO is a hormone produced by the kidney that promotes the formation of red blood cells by the bone marrow. For the in vitro production of transgenic embryos, the different expression vectors were transduced into holstein ear fibroblast cells, respectively, and GFP expressed donor cells were transferred into enucleated oocytes, and then the reconstructed SCNT embryos were developed into pre-implantation stage. From three replicates, GFP expressed 112 transgenic SCNT embryos were produced. When their cleavage rate and blastocyst rate were compared with non-transgenic SCNT embryos, the results were presented into 73.2% vs. 76.9% and 26.8% vs. 30.6%, respectively, there were no differences. Also, total cell number and ICM cell numbers of day 8 blastocysts were statistically not different between the transgenic SCNT groups (120.6±7.9 and 31.4±8.2) and control SCNT group (128.3±4.8 and 35.3±4.0). The GFP expression levels were presented consecutively high during the culture of transgenic SCNT embryos. By analysis of semi-quantitative RT-PCR, the relative expression levels of hEPO mRNA and pluripotent gene were determined. These results demonstrated that the hEPO expressed transgenic bovine embryos can be efficiently produced in vitro by SCNT technique, while their potential of cloned animal production have to be examined in further study.

Stem cell therapy is undoubtedly the most promising therapeutic approach for neurological disorders. Adipose tissue is ubiquitous and it can be easily harvested in large quantities under local anesthesia with little patient discomfort, making adipose tissue into the ideal large-scale source for research on clinical applications. In this study we monitored the neuronal cell differentiation potential of human adipocyte in the following condition; i) N2 medium containing 200 uM ascorbic acid (AA) and/or 10 uM flavonoid (F) and ⅱ) N2 medium containing AA and/or 10 ng/ml brain derived neurotrophic factor (BDNF) and/or, 200 ng/ml sonic hedgehog (SHH) plus 100 ng/ml fibroblast growth factor (FGF) 8. Adipose stem cells were cultured in above described differentiation condition for three weeks. RT-PCR analysis demonstrated that the mRNA levels of neuronal cell markers in differentiated adipose stem cells. Under the culture condition using N2 medium containing AA, the expression level of nestin (neural progenitor marker) m- RNA was high in all groups, while those of Neuro D, and LEP and FABP4 (adipocyte marker) mRNA were significantly decreased. Also, the addition of BDNF or SHH+FGF8 in N2 medium containing AA enhanced the neural cell differentiation from adipose stem cells, the expression level of Map2 (mature neuron) mRNA was increased, and that of TH (dopaminergic neuron marker) mRNA was high. In addition, we confirmed that the flavonoid addition has effect on the increase of Map2 expression. These results demonstrate that our designed culture condition has effect on the neural cell differentiation of adipose stem cells and this stimulatory effect may be further enhanced by transplantation.

Somatic cell nuclear transfer (SCNT) is an efficient technique which has been successfully applied to developmental biology, and resulted in the production of offspring from various species. It offers many opportunities in basic and medical research as well as endangered species preservation. On the other hand, embryonic stem (ES) cells are useful research tools for genetic engineering and developing disease models. In previous study, we established bovine IVF embryo derived ES cell line which can be grow indefinitely as undifferentiated cell state. In this study, we compared the effect of two different age cells (bovine ES cell; JNU-ibES-05 or adult ear fibroblast cell) on in vitro developmental potential of bovine SCNT embryo. To produce SCNT embryos, the ES cells or somatic cells were dissociated and transferred into enucleated MⅡ oocytes, and cleaved reconstructed embryos were cultured in CR1aa medium containing 10% FBS, 1 ug/ml epidermal growth factor (EGF) and 1 ug/ml insulin growth factor (IGF) for 8 days. In the result, blastocyst development rate was similar between ES cell treatment group and somatic cell treatment group, 27.7% (10/36) and 28.9% (11/ 38), respectively. However, there was particular difference in development speed from day 5 post SCNT, blastocyst expanding was 1 day faster in ES cell group than in somatic cell group. This difference was analyzed by semi-quantitative RT-PCR using pluripotency, growth and cell cycle gene markers. These results demonstrated that SCNT embryo using ES cell as a donor cell has better growth potential than somatic cell, and it will be a useful tool for a transgenic animal production.

It is known that oocytes can be activated without male contribution in vitro and develop to blastocysts which are used to isolate parthenogenetic embryonic stem (ES) cells. Differentiation capacity of the parthenogentic ES cells was rather lower than that of fertilized embryos derived ES cells, which might be the result of the absence of male genome. However, parthenogenetic ES cells might be useful research tool for genetic engineering and generating SCNT embryo derived ES cells. In our previous study, we reported that establishment of several bovine ES cell lines from in vitro fertilized (IVF) embryos named JNU-ibES. Based on this data, the objective of this study is to generate parthenogenetic ES cells and to examine their stem cell characteristics. Total 107 parthenogenetic embryos produced at day 8 or 9 were classified into their developmental stages (full expanded x 40, hatched x 67). For producing ES cells, ICM and trophetoderm-rich clumps were mechanically dissociated and were cultured on mitomycin- C treated mouse embryonic fibroblast feeder cell drop and covered with mineral oil in DMEM medium containing 20% FBS, 5 ng/ml basic FGF, 1% nonessential amino acids, and 0.55 mM b-mercaptoethanol. We obtained 20 primary parthenogenetic bovine ES (pbES)-like cell colonies. And pbES colony formation was higher in hatched blastocyst (25.4%, 16/67) than expanded blastocysts (10%, 4/40). Among those colonies, 5 pbES cell lines were successfully established and they were named as a series of JNU-pbES. These pbES cells were positively expresssed pluripotency markers such as Oct4, Nanog, TRA-1-81, SSEA-1 and alkaline phosphatase. This result demonstrated that the establishment efficiency and characteristics of pbES cell line was very similar to those of ibES cell line.

The generation of patient-specific pluripotent stem cells has the potential to accelerate the implementation of stem cells for clinical treatment of degenerative diseases. This study was to examine the in vitro neuron cell differentiation characteristics of our established human (h) iPS cells (IMR90-iPS-1~2) derived from human somatic cells. For the neuron differentiation, well grown hiPS colonies were recovered by collagenase treatment and then suspended cultured in a non-adherent bacteriological culture dish using human embryonic stem (hES) cell culture medium for 4 days. Embryoid bodies were plated and cultured in serum-free ITSFN (insulin/transferrin/selenium/fibronectin) medium for 8 days to select neural precursor cells. Then selected neuronal cells were dissociated, plated onto poly-L-ornithin/laminin coated dish at a concentration of 2 x 105 cells/cm2 and expanded in N2 medium containing 20 ng/ml bFGF, 200 ng/ml SHH and 100 ng/ml FGF-8 for 7 days. For the final differentiation step involved removing agents and culturing for 14 days in 20 ng/ml BDNF added N2 medium. In the neural precursor stage, >90% of nestin positive cells and >50% NCAM positive cells were obtained. Also, in final differentiation step, we confirmed the high percent (>80%) of mature neuron tubulin-β positive cells and approximately >20% of tyrosine hydroxylase positive cells. Also, these results were confirmed by RT-PCR. These results indicated that hiPS cells have potential to generate specific neuron differentiation and especially TH+ neuron was also can be obtained, and thus hiPS-derived neural cells might be an usable source for the study of neuro-degenerative disease.

An entomopathogenic filamentous fungus, Paecilomyces lilacinus strain HY-4, has a great potential as a promising bio-pesticide due to its superior pathogenicity against Adoretus tenuimaculatus and Tetranychus urticae. When the fungal strain infects host cuticle, it secrets a combination of hydrolytic enzymes including chitinase to solubilize the cuticle. Thus, we investigated effects of different carbon and nitrogen sources on the production of a chitinase from P. lilacinus strain HY-4. The organism produced an extracellular chitinase at a relatively high level (45.4 mU/ml) when cultivated for 5 days on a medium supplemented with insect pupa (0.5%) and colloidal chitin (1%), which was prepared by treating chitin from crab shells (Sigma-Aldrich Co. Ltd.) with 12 N HCl solution. However, extracellular secretion of chitinase by strain HY-4 was found to be significantly repressed in the presence of glucose (1%).

The extracellular GH11 β-1,4-xylanase (XylY) gene (633-bp) of Paenibacillus sp. strain KYJ-16 was molecularly cloned by repeated DNA walking and nested PCR method. The xylY gene was predicted to encode an extracellular protein consisting of 611 amino acids with a nesuced molecular mass of 23 kDa and a calculated pI of 9.55. Protein blast search revealed that the enzyme consisted of a putative catalytic domain, which is homologous to a catalytic GH11 domain. The highest sequence identity (92%) was obtained as the catalytic GH11 domain of XylY was compared to that of Paenibacillus sp. strain HGF5 (GenBank accession number: EGG35584) that has not yet been characterized. Enzymatic properties of the recombinant His-tagged enzyme (rXylY) overexpressed in E. coli BL21 harboring pET-28a(+)/xylY will be also presented.

The gene (2,304-bp) encoding a novel xylanolytic enzyme (XylD) with a catalytic domain, which is 70% identical to that of Cellulomonas flavigena DSM 20109 GH6 β-1,4-cellobiohydrolase, was identified from an earthworm (Eisenia fetida)-symbiotic bacterium, Cellulosimicrobium sp. strain HY-13. The enzyme consisted of an N-terminal catalytic GH6-like domain, a fibronectin type 3 (Fn3) domain, and a C-terminal carbohydrate-binding module 2 (CBM 2). XylDΔFn3-CBM 2 displayed high transferase activity (788.3 IU mg-1) toward p-nitrophenyl (PNP) cellobioside, but did not degrade xylobiose, glucose-based materials, or other PNP-sugar derivatives. Birchwood xylan was degraded by XylDΔFn3-CBM 2 to xylobiose (59.2%) and xylotriose (40.8%). The transglycosylation activity of the enzyme, which enabled the formation of xylobiose (33.6%) and xylotriose (66.4%) from the hydrolysis of xylotriose, indicates that it is not an inverting enzyme but a retaining enzyme. The endo-β-1,4-xylanase activity of XylDΔFn3-CBM 2 increased significantly by approximately 2.0-fold in the presence of 50 mM xylobiose.

xylanolytic gut bacterium isolated from Eisenia fetida, Cellulosimicrobium sp. strain HY-13, produced an extracellular glycoside hydrolase capable of efficiently degrading mannose-based substrates such as locust bean gum (LBG), guar gum, mannotetraose, and mannopentaose. The purified mannan-degrading enzyme (ManS, 34,926 Da) from strain HY-13 was found to have an N-terminal amino acid sequence of DEATTDGLHVVDD, which has not yet been identified. Under the optimized reaction conditions of 50℃ and pH 7.0, ManK exhibited extraordinary high specific activities of 7,109 IU/mg and 5,158 IU/mg toward LBG and guar gum, respectively, while the enzyme showed no effect on sugars substituted with p-nitrophenol and various non-mannose carbohydrates. ManK strongly attached to Avicel, lignin, β-cyclodextrin, and poly(3-hydroxybutyrate) granules, but not bound to chitin, chitosan, curdlan, or insoluble oat spelt xylan. The aforementioned characteristics of ManS suggest that it is a unique endo-β -1,4-mannanase with out additional carbohydrolase activities, which differentiates it from other well-known carbohydrolases.

Paecilomyces lilacinus HY-4 is an entomopathogenic filamentous fungus that has exhibited insecticidal activity against Adoretus tenuimaculatus and Tetranychus urticae. Strain HY-4 has attracted a great deal of industrial concerns because this organism can be applicable as a potent bio-pesticide. In this study, we developed an optimal diphasic fermentation technique for HY-4 conidial production. The substrate prescription which was made up of hulls or brans was obtained by screening of agricultural products, and the conidial production could reach a minimum of 2.5×1010 conidia/g after solid fermentation for 12 days in a given condition. It was interesting to note that strain HY-4 was propitious to sporulate more efficiently and productively in liquid fermentation process in the presence of insect pupa. For the industrial application of the HY-4 spores, their pH and thermal stabilities were evaluated on SDA agar plate as well. Additionally, the germination rate of HY-4 spores was still above 90% even when they were stored for 5 months at ambient temperature.