• Asian-Australasian Journal of Animal Sciences
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• v.13 no.2
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• pp.161-166
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• 2000

This study was designed to determine the effects of the insulin-like growth factor (IGF-1) and estradiol $17-{\beta}$ on the in vitro proliferation of stromal vascular cell from Hanwoo omental, subcutaneous, intermuscular and intramuscular adipose tissues. Cells were cultured in M199+20% newborn calf serum and the proliferation of cells was measured by direct microscopic cell counting and change of genomic DNA amount. Cell numbers increased slightly over the first 72 hour of culture and then increased greatly, regardless of adipose tissue depots. In IGF-1 treatment, the number of omental preadipocytes maintained highest level from the beginning to the 20th day of culture. However, in estradiol-$17{\beta}$ treatment, those tended to be lower than the control from the beginning of culture and significantly lower at the 24th day. When IGF-1 was added to subcutaneous preadipocytes, the numbers of cells were higher from 11th day than those from other treatments, although there was no statistical significance. For intermuscular preadipocytes treated with IGF-1, its numbers were significantly (p<0.05) higher at 11th day, and in the other days it showed a similar tendency to those of the subcutaneous tissue. In this experiment, preadipocytes were taken from 24 month old fully matured steers and the highest proliferation rate was shown in intramuscular tissue followed by those of subcutaneous preadipocytes. Addition of $5{\mu}M$ estradiol-$17{\beta}$ to the growth medium failed to promote the replication of Hanwoo preadipocytes, as indicated by direct cell counts and total genomic DNA content. As the culture period proceeded, the amounts of DNA were increased, but the patterns of increment were not consistent with the results of cell numbers.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.4
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• pp.446-450
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• 2000

The experiment was conducted to study the effects of water soluble vitamins and retinoic acid on the differentiation of preadipocyte from omental, subcutaneous, intermuscular and intramuscular adipose tissue of Hanwoo. Differentiation was assessed by the change in enzyme activity, glycerol-3 phosphate dehydrogenase in serum free cell culture system. Preadipocytes treated with biotin ($10{\mu}M$) and pantothenic acid ($100{\mu}M$) were significantly (p<0.05) less differentiated than those from the control in all adipose tissue depots except intramuscular tissue. Although there was no significance, vitamin C was shown to stimulate the adipocyte conversion in omental and subcutaneous, but not in intermuscular and intramuscular adipose tissues. Lower values of GPDH activity in intermuscular preadipocyte were interpreted to be caused by relatively higher amounts of protein. In this experiment vitamin C did not stimulate fat deposition in intramuscular adipose tissue but further experiments are needed on the role of vitamin C in preadipocyte differentiation. When treated with different levels of retinoic acids, differentiation of preadipocytes was significantly (p<0.05) reduced from the level of $0.5{\mu}g/ml$ in omental and intermuscular, from $50{\mu}g/ml$ in subcutaneous, and in intramuscular at $500{\mu}g/ml$, thus showing that intramuscular preadipocytes were least responsive to retinoic acid in differentiation. All-trans retinoic acid appeared to inhibit the differentiation in a dose dependent manner, regardless of adipose tissues type.

• Journal of Animal Science and Technology
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• v.51 no.6
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• pp.443-452
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• 2009

Adipocytes are differentiated from preadipocytes and have large capacity for storing fats inside cells. In cattle, intramuscular fat (IMF) content is one of the major determinants for meat quality and also highly affects market prices, especially in Japan and Korea. In order to profiling differentially expressed genes between intramuscular fibroblast-like cells (preadipocytes) and their differentiated adipocytes, we have established intramuscular fibroblast-like cells from M. longissimus thoracis in Korean cattle (Hanwoo). The differentially expressed genes were selected by comparing these two types of cells ug thecommercially available 23kese two types of cells ug theco. The results indan ced that 206 arecomelements were differentially expressed. Of these, 67 and 94 ks wn genes were up and d wn regulaced, respectively, in adipocytes ug ng both 2-fold difference and Welch's t-test as the cut-off points. The differentially expressed genes identified in this study can be used as good markers for improving meat quality traits with further verification of their biological functions, especially IMF contents in cattle.

• Journal of Animal Science and Technology
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• v.64 no.6
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• pp.1173-1183
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• 2022

Adipogenesis is a complex process comprising commitment and a differentiation stages. Through research, many different transcriptional factors were found to mediate preadipocyte commitment and differentiation. Lysine has a potential of regulating the commitment and differentiation of preadipocytes. In the present study, intramuscular stromal vascular cells (SVC) isolated from Hanwoo beef cattle were used to elucidate the effects of low lysine level on adipogenesis. SVC were isolated and incubated with various concentrations of lysine (0, 37.5, 75, 150 and 300 µg/mL). No significant difference were observed in the proliferation of SVC after 24 and 48 h of incubation with different concentration of lysine. On preadipocyte determination, reducing the level of lysine significantly increased the expression of preadipocyte commitment gene Zinc finger protein 423 and Preadipocyte factor-1. Upon differentiation, Oil Red O staining revealed that lipid accumulation and triglyceride content significantly increased with the decreasing lysine levels in the media. Expression levels of peroxisome proliferator-activated receptor-γ, CCAAT enhancer binding protein-α, sterol regulatory element binding protein-1c, Fatty Acid Binding Protein 4 and stearoyl CoA desaturase were upregulated by the decreased level of lysine. These data suggest the potential mechanism of action for the improved preadipocyte commitment and adipocyte differentiation in bovine intramuscular SVC upon treatment with low levels of lysine. These findings may be valuable in developing feed rations that promote deposition of intramuscular fat in beef cattle through lysine level modification.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.913-918
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• 2005

The development of marbling in cattle is closely associated with an increase in adipocyte size and number within muscle. The adipose precursor cells have the capacity to differentiate into adipocytes within the muscle during the formation of marbling. In this studies, we established the cell culture system for differentiation of intramuscular preadipocyte isolated from the sirloin of Hanwoo aged 12 months. The intramuscular preadipocyte cells exhibited a fibroblastic appearance and differentiated into adipocytes by treating confluent cells with differentiation medium containing insulin, dexamethasone, and troglitazone. When intramuscular preadipocyte cells were differentiated at 18 day, the triglyceride concentration was higher than control cells. Moreover, the thiazolidinedione treatment increased adipogenesis. RT-PCR analysis confirmed the significant expression of PPARγ mRNA during adipocyte differentiation. In conclution, our culture system used in this study allowed intramuscular preadipocyte cells to differentiated into adipocytes and intramuscular preadipocyte cells may be useful in the further study of differentiation mechanism of adipocytes in Hanwoo.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.1087-1094
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• 2005

The uptake of glucose for metabolism and growth is essential to most animal cells and is mediated by glucose transport protein. In the glucose transport protein family, GLUT4 plays a key role in cellular glucose uptake stimulated by insulin in skeletal muscles and adipose tissue in rodents and human. In this studies, we reported the identification, characterization, and expression of Hanwoo GLUT4 gene. The Hanwoo GLUT4 cDNA includes a 1527 bp open reading frame encoding a protein of 509 amino acids. The GLUT4 amino acid sequences of the Hanwoo show strong conservation with the corresponding sequences reported in other species. The highest mRNA expression of GLUT4 was detected in heart and lower expression was detected in rib meat, sirloin, and colon. We confirmed the expression of GLUT4 in the subcutaneous and small intestinal adipose tissue using RT-PCR. To investigate the expression of GLUT4 in the bovine intramuscular adipose differentiation, fibroblast-like cells were isolated from the sirloin of Hanwoo bull aged 12 months by collagenase digestion of minced tissue and cultured with activators of PPAR gamma. We identified that GLUT4 mRNA expression decreased during differentiation of preadipocytes into adipocyte in Korean cattle. These results indicated that function of GLUT4 in bovine adipose tissue was different from that of mouse and human.