• Journal of Nutrition and Health
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• v.34 no.5
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• pp.485-492
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• 2001

The prevalence of type 2 diabetes mellitus has been rapidly increased in parallel with the westernization of eating behavior in Korea. Increased consumption of animal fat and simple sugar can be potential contributors for insulin resistance. The purpose of the study was to determine whether Western-(WD) and Korean-style(KD) diets altered insulin secretion and insulin resistance in male Sprague Dawley rats. Rats weighing 98$\pm$5g were provided by KD(77 En% of starch, 5 En% of corn oil and 13 En% of gluten plus 5 En% of casein), WD(42 En% of starch, 40 En% of butter and 18% of casein) or control diet(62 En% of starch, 20 En% of corn oil and 18% of casein) for 12 weeks. Body weights were lower in KD compared to WD. Fasting blood glucose levels were not different among diets. Insulin secretion from the beta cells was higher by 2.2$\pm$0.4 folds in WD than KD at baseline. In hyperglycemic clamp insulin secretion was higher in WD than KD and CD. Whole body glucose disposal rates referred to the state of insulin sensitivity were lowest in WD among groups. Glycogen deposits in soleus and quadriceps muscles were lowest in WD among all groups, but their triglyceride contents were highest. GLUT4 contents and glycogen synthase were lowest in WD in both muscles. In conclusions, westernization of diets needed more insulin to normalization of blood glucose levels due to increased insulin resistance. Thus, WD would lead to increased prevalence of diabetes mellitus when increased insulin resistance could not be compensated by insulin secretion in the case of elevated blood glucose levels. (Korean J Nutriton 34(5) : 485~492, 2001)

• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.121-126
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• 2014

Recently, infant formula products made of caprine milk have gained popularity, mainly because the nutritional composition of caprine milk is similar to that of human milk. In addition, caprine milk is considered to be better than bovine milk in terms of nutrient composition and easier digestion. Compared to bovine milk, caprine milk contains more ${\beta}$-casein, but less ${\alpha}$S1-casein. While the lactose concentration of both bovine and caprine milk is almost the same, a content of total oligosaccharides in caprine milk was approximately five to eight times higher than that in bovine milk. However, as the dairy goat industry in Korea is in a nascent stage of milk production and further processing, many nutritional advantages of caprine milk over bovine milk are not fully conveyed to general consumers. It is recommended that scientific research regarding the nutritional benefits of caprine milk needs to be conducted urgently, owing to the increasing domestic sales of infant formula products made of caprine milk.

• Reproductive and Developmental Biology
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• v.32 no.3
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• pp.153-158
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• 2008

Tissue-specific and temporal regulation of milk protein gene expression is advantageous when creating transgenic animal that produces foreign protein into milk. Gene expression, i.e. protein production, is regulated not only by promoter strength but also mRNA stability. Especially, poly A tail length by polyadenylation affects in vivo and in vitro mRNA stability and translation efficiency of the target gene. In the present study, nucleotide sequence of 3'-UTR was analyzed to evaluate the effects of mRNA stability on the target gene expression. Based on the poly A signal of 3' -untranslated region (UTR), nucleotide sequences of putative cytoplasmic polyadenylation elements (CPEs) and downstream elements (DSEs: U-rich, G-rich, GU-rich) were analyzed and used to construct 15 luciferase reporter vectors. Each vector was transfected to HC11 and porcine mammary gland cell (PMGC) and measured for dual luciferase expression levels after 48 hours of incubation. Luciferase expression was significantly higher in construct #6 (with CPE 2, 3 and DSE 1 of exon 9) and #11 (with CPE 2, 3 and DSE 1, 2 and 3 of exon 9) than construct #1 in the PMGC. These results suggest that expression of target genes in PMGC may be effectively expressed by using the construct #6 and #11 on production of transgenic pig.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.86-86
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• 2003

Research has been in progress for more than a decade to production of useful proteins by genetic modification in cattle. However, the levels of protein production in transgenic cattle have been reported very low. To enhance protein production in transgenic animal, we tried homologous recombination to donor cells for production of transgenic clone cattle through nuclear transfer procedure. Thus, we constructed the two targeting vectors of human thrombopoietin (TPO) at bovine $\beta$-casein locus using homologous recombination with 13.6 kb and 9.6 kb homology. In two targeting vectors, positive selection was through the neomycin resistance gene and negative selection was by the diphtheria toxin (DT). Gene targeting was attempted in bovine embryonic fibroblasts (bEF) and bovine ear skin fibroblasts (bESF). To determine the most appropriate concentration of neomycin for bEF and bESF, G4l8 resistance was confirmed by culturing the cells in various concentrations of the drug and both of the cells were optimally selected at $900 \mu g/ml$ of neomycin. The transfected bEF and bESF by the targeting vectors were colonized efficiently at the ratio of DNA to transfection reagent such as $4 \mu g$:2 ${mu}ell$ and $1 \mu g$:$2 \mu l$. Comparing number of healthy clones from passage 4 to passage 8, bESF (17%) persist in culture for much longer than bEF (6%). The two gene-targeted bESF clones of 30 random-integrated clones with 9.6 kb homology length were confirmed, however, nothing was out of 72 random integration clones with 13.6 kb homology length, The DT also worked more efficiently in clones transfected with the vector of 9.6 kb homology length. Our data suggests that the choice of donor cell for long culture period should be considered to obtain targeted cell clone, and the gene-targeting frequency and the DT working efficiency are dependent on the length of target homology.

• BMB Reports
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• v.42 no.12
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• pp.840-845
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• 2009

Mitogen- and stress-activated protein kinase (MSK1) palys a crucial role in the regulation of transcription downstream of extracellular-signal-regulated kinase1/2 (ERK1/2) and mitogen-activated protein kinase p38. MSK1 can be phosphorylated and activated in cells by both ERK1/2 and p38$\alpha$. In this study, Casein Kinase 2 (CK2) was identified as a binding and regulatory partner for MSK1. Using the yeast two-hybrid system, MSK1 was found to interact with the CK2$\beta$ regulatory subunit of CK2. Interactions between MSK1 and the CK2$\alpha$ catalytic subunit and CK2$\beta$ subunit were demonstrated in vitro and in vivo. We further found that CK2$\alpha$ can only interact with the C-terminal kinase domain of MSK1. Using site-directed mutagenesis assay and mass spectrometry, we identified five sites in the MSK1 C-terminus that could be phosphorylated by CK2 in vitro: Ser757, Ser758, Ser759, Ser760 and Thr793. Of these, Ser757, Ser759, Ser760 and Thr793 were previously unknown.

• Animal Bioscience
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• v.34 no.1
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• pp.2-11
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• 2021

Objective: The aim of the study was to evaluate the influence of polymorphic loci and other factors on milk performance and the technological properties of milk. Methods: The analysis was performed on Simmental and Holstein cows in field conditions (n = 748). Milk yield in kg, fat and protein percentage and yield were evaluated. Technological properties were evaluated by milk fermentation ability, renneting, and an alcohol test. Polymorphisms in the acyl-CoA diacylgycerol transferase 1 (DGAT1), leptin (LEP), fatty acid synthase (FASN), stearoyl CoA desaturase 1 (SCD1), casein beta (CSN2), casein kappa (CSN3), and lactoglobulin beta genes were genotyped, and association analysis was performed. Results: The DGAT1 AA genotype was associated with higher milk, protein and fat yields (p<0.05). The MM genotype in the LEP gene was associated with a lower protein percentage and the W allele with a higher protein percentage (p<0.05). In cows with the FASN GG genotype, the protein percentage was higher, but the A allele was associated with higher milk, protein and fat yields than the G allele. The TT genotype in SCD1 was associated with the lowest milk, protein and fat yields and with the highest milk protein percentage (p<0.01). The T allele had higher values than the C allele (p<0.05) except for fat percentage. The genotype CSN3 AA was associated with a significantly heightened milk yield; BB was associated with a high protein percentage. The effect of the alleles on the technological properties was not significant. The CSN2 BB genotype was associated with the best alcohol test (p<0.01), and the renneting order was inverse. Milk from cows with the CSN2 A1A1 genotype was best in the milk fermentation ability. CSN3 significantly affected the technological properties. Conclusion: The findings revealed the potential of some polymorphic loci for use in dairy cattle breeding and for the management of milk quality. In field research, the pivotal role of farms in milk yield, composition and technological properties was confirmed.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.9
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• pp.1332-1338
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• 2003

This study was undertaken to examine the influence of soluble non-starch polysaccharides on growth performance, mucin secretion, and endogenous amino acid flows in weaner pigs. Different levels (0, 4 and 7.5%) of purified corn arabinoxylan (AX) or barley $\beta$-glucan extract (BG) were substituted for cellulose in a purified diet based on starch, sucrose and enzymatically hydrolyzed casein. All diets contained titanium oxide as an indigestible marker. Each experimental diet was fed to five, 6-wk old weaner pigs for 21 days. Average daily gain (p<0.05) and feed conversion ratio (p<0.01) were improved with dietary inclusion of 7.5% AX and BG, indicating high degradation rates of AX and BG in pigs. Crude mucin contents and endogenous nitrogen flow were increased (p<0.05) with increased levels of AX, but not with BG. Numerical increases in endogenous amino acid flow (EAAF) were observed with increased levels of AX but no definite trend with BG. Endogenous amino acid flow in pigs fed mixed NSP diets (4% BG and 3.5% cellulose) was significantly higher (p<0.05) than those fed 7.5% BG diets. Among diets containing pure sources of soluble non-starch polysaccharides, endogenous amino acid flows were highest in 7.5% AX (p<0.05), intermediate in BG, and lowest in control diet. Increased flows (p<0.01) of threonine, proline and serine in pigs fed 7.5% AX diets are consistent with the increased flow of crude mucin determined in this treatment. In conclusion, mucin and endogenous amino acid flows were increased with dietary inclusion of AX, which could be related to its physicochemical property, particularly its high water-holding capacity. In contrast, $\beta$-glucan, due to its high degradation rate in pig, may be considered as unimportant factor in inducing mucin and endogenous amino acid secretions, at least at levels such as those used in this study.

• Journal of Dairy Science and Biotechnology
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• v.42 no.2
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• pp.23-34
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• 2024

Milk, which is often referred to as a healthy beverage, is the first food encountered at birth. During digestion, A1-type milk often leads to digestive disorders due to increased levels of 𝛽-casomorphin-7. It also tends to induce inflammatory responses in the gut immune system by altering the gut microbiota and triggering conditions such as diabetes and respiratory hypersensitivity. In contrast, A2-type milk is gaining attention because of fewer associated problems than A1 milk and its unique functional benefits. However, information on the efficacy of A2 milk relies primarily on limited clinical and animal trial data, and substantiating its efficacy and functional superiority remains a challenge. Therefore, various studies, including research on the distinctive efficacy and functions of A2 milk compared with conventional A1 milk and investigations into the mechanisms underlying its effects on human health following consumption, are necessary in the future.

• The Journal of Korean Obstetrics and Gynecology
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• v.23 no.1
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• pp.12-29
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• 2010

Purpose: This study was conducted to investigate the effect on factors related lactation after administration of Palmul-tang in postpartum C57BL/6N mice. Materials and Methods: Experimental groups were divided into control group post-par group and pre-par group. Pre-par and post-par group were administered Palmul-tang(p.o) twice a week for 4 weeks or 3 weeks respectively. Control group was administered normal saline for 3 weeks. Then we observed morphological change, immunohistochemical density and milk protein gene expression of factors related lactation within mammary gland of postpartum mice. Results: In post-par and pre-par groups, adipose tissue within mammary gland significantly decreased, and ductal branch and alveoli prominently developed than that of control group at 1~3 weeks after administraion of Palmul-tang. In post-par and pre-par groups, density of immunoreactivity on oxytocin, prolactin, estrogen and progesterone receptors in mammary glandular tissue significantly increased than that of control group. mRNA expression of $\beta$-casein and placental lactogen (PL)-1 in post-par group was more increased than that of control and pre-par groups. Conclusion: These results suggest that Palmul-tang significantly improved factors related lactation at postpartum period.

• Journal of Food Hygiene and Safety
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• v.15 no.2
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• pp.173-175
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• 2000

Nine strains of pathogenic Vibrio sp. of clinical and environmental origin were examined for the degradation of gelatin, casein and hemolysin which is important to the virulence of this bacterium. Culture filtrates of all nine strains of Vibrio exhibited proteolytic activities. Especially, four strains of V. parahaemolyticus and one V. alginolyticus showed strong gelatin-degrading activity. In terms of hemolytic activity, three V. parahaemolyticus and V. mimicus showed strong $\beta$-hemolysis whereas those of strains of V. alginolyticus, V. fluvialis, V. vulnificus examined lacked this activity.