• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.2
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• pp.155-160
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• 2000

In order to understand the effects of sex or age on cellular characteristics of adipocytes from Hanwoo and sheep, samples were obtained from omental, subcutaneous, intermuscular and intramuscular adipose tissue depots of bulls, steers, heifers and cows in Hanwoo, and perirenal, omental and subcutaneous adipose tissues of fetal lambs, suckling lambs and wethers in sheep. In case of Hanwoo, mean diameter, surface area and volume of adipocytes from each depot were obtained by multisizer II (Coulter Co., UK). Osmium-fixed adipocytes were sized and counted using $560{\mu}m$ aperture. For samples obtained from sheep, cellularity was measured by using microscope and MCV program of Texas Instrument. Bulls had less subcutaneous and kidney fat than steers even though their slaughter and carcass weight were heavier. The amounts of fat from cows were greater in subcutaneous, kidney and internal organs than heifers. Steers had larger adipocytes in subcutaneous, intermuscular and intramuscular adipose tissues than bulls, although the differences were significant only for the subcutaneous adipose tissue depots. Adipocytes appeared to be largest in omental and smallest in intramuscular adipose tissue, although there were no significant differences among tissues. In a comparison of heifers and cows, significant site effects (p<0.05) were shown in adipocyte diameter, surface area and volume, and adipocyte appeared to be largest in omental tissue. Statistical difference (p<0.05) was only shown in cell volume of intramuscular tissue which was higher in cow than heifer. Intramuscular adipose tissue tended to have relatively greater numbers of cells per gram tissue and reflect lesser maturity of intramuscular adipose tissue relative to other adipose tissues. In sheep, regardless of adipose tissue depots, wethers had the greater adipocyte diameters than those at any other growth stage of sheep. Within adipose depots, the ranking of cell size was the greatest in the omental tissue of wether and the lowest in the renal and subcutaneous adipose tissue depots of fetal lamb. The cell size of adipocyte became larger with age, especially from fetal to suckling lamb due to a rapid hypertrophy of both perirenal and subcutaneous adipocytes during the suckling period.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.6
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• pp.914-918
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• 2018

Objective: The relationship between water-holding capacity (WHC) and intermuscular fat (IMF) was studied in Japanese commercial pork. Methods: Longissimus muscles of pigs (n = 62), obtained from two meat packing plants, were analyzed for IMF content, moisture content, drip loss, cooking loss, and pH. Pairwise relationships among these traits were determined using correlation analyses. Results: IMF content was significantly correlated with moisture content (r = -0.88; p<0.01) and pH (r = 0.32; p<0.05), but not with drip loss (r = -0.23; p = 0.07) or cooking loss (r = -0.10; p = 0.42). In contrast, drip loss was significantly (and negatively) correlated with pH (r = -0.57; p<0.01). Conclusion: IMF content was not significantly correlated with WHC in pork, and so ultimately, we consider pH to be one of the most important factors influencing WHC in pork meat.

• Food Science of Animal Resources
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• v.36 no.6
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• pp.709-718
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• 2016

This review addresses the characteristics and health benefit of highly marbled Wagyu and Hanwoo beef. Marbling of Wagyu and Hanwoo beef has been increased in Japan and Korea to meet domestic consumer preferences. Wagyu and Hanwoo cattle have high potential of accumulating intramuscular fat (IMF) and producing highly marbled beef. The IMF content varies depending on the feeding of time, finishing diet, and breed type. IMF increases when feeding time is increased. The rate of IMF increase in grain-fed cattle is faster than that in pasture-fed cattle. Fatty acid composition are also different depending on breeds. Highly marbled Wagyu and Hanwoo beef have higher proportions of monounsaturated fatty acid (MUFA) due to higher concentrations of oleic acid. MUFAs have little effect on total cholesterol. They are heart-healthy dietary fat because they can lower low-density lipoprotein (LDL)-cholesterol while increasing high-density lipoprotein (HDL)-cholesterol. Clinical trials have indicated that highly marbled beef does not increase LDL-cholesterol. This review also emphasizes that high oleic acid beef such as Wagyu and Hanwoo beef might be able to reduce risk factors for cardiovascular disease.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.11
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• pp.1777-1782
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• 2007

Beef producers are trying to produce not only better quality but also greater quantity of beef in order to meet the preferences of some consumers at a lower cost. This can be accomplished if we understand the factors regulating lipid deposition in intramuscular adipose tissue and the tenderness of meat. Propylene glycol (PG) might be used as a precursor of intramuscular fat synthesis especially in the late period of fattening because adipose tissue in ruminants is thought to mature sequentially in abdominal, intermuscular, subcutaneous and intramuscular depots. The action of cholecalciferol supplementation has been verified in producing more tender meat through the enhancement of calpain activity over the postmortem ageing period. A synergistic effect can be expected if the dietary cation and anion difference (DCAD) technique is used in combination with dietary supplementation of cholecalciferol. In another approach, the optimization of hormonal implant use also may provide similarly marbled beef at a much lower cost.

• 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.

• Food Science of Animal Resources
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• v.29 no.6
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• pp.685-694
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• 2009

The aim of the present study was to evaluate the variation in ultimate pH of commercial populations of pure-breed (Landrace, Duroc and Yorkshire) pig's longissimus muscles and their effect on objective meat quality traits and sensory characteristics. Fifty boars were sampled from 184 pigs, which were reared at three breeding farms and slaughtered at a commercial abattoir. The selection was determined based on ultimate pH, and animals were segregated into three groups: low pH (pH $\leq$ 5.5, n=13), medium pH (pH 5.5 to 5.6, n=18) and high pH (pH $\geq$ 5.6, n=16). The breeds had no significant effects; however, pigs with a higher ultimate pH had significantly (p<0.05) higher intramuscular fat content, lower level of polyunsaturated fatty acids, lower level of lipid oxidation and higher eating quality compared to those with lower ultimate pH. As the ultimate pH increased, the relative proportion of C14:0, C16:0 and C18:1 increased while C18:2n6 and C20:4n6 decreased. The present study demonstrates that the economic value of pigs can be characterized by the ultimate pH and/or intramuscular fat content. However, these results do not necessarily indicate that a high ultimate pH directly corresponds to high intramuscular fat content and vice versa.

• Animal Bioscience
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• v.35 no.1
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• pp.115-125
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• 2022

Objective: Intramuscular fat (IMF) is a critical economic indicator of pork quality. Studies on IMF among different pig breeds have been performed via high-throughput sequencing, but comparisons within the same pig breed remain unreported. Methods: This study was performed to explore the gene profile and identify candidate long noncoding RNA (lncRNAs) and mRNAs associated with IMF deposition among Laiwu pigs with different IMF contents. Based on the longissimus dorsi muscle IMF content, eight pigs from the same breed and management were selected and divided into two groups: a high IMF (>12%, H) and low IMF group (<5%, L). Whole-transcriptome sequencing was performed to explore the differentially expressed (DE) genes between these two groups. Results: The IMF content varied greatly among Laiwu pig individuals (2.17% to 13.93%). Seventeen DE lncRNAs (11 upregulated and 6 downregulated) and 180 mRNAs (112 upregulated and 68 downregulated) were found. Gene Ontology analysis indicated that the following biological processes played an important role in IMF deposition: fatty acid and lipid biosynthetic processes; the extracellular signal-regulated kinase cascade; and white fat cell differentiation. In addition, the peroxisome proliferator-activated receptor, phosphatidylinositol-3-kinase-protein kinase B, and mammalian target of rapamycin pathways were enriched in the pathway analysis. Intersection analysis of the target genes of DE lncRNAs and mRNAs revealed seven candidate genes associated with IMF accumulation. Five DE lncRNAs and 20 DE mRNAs based on the pig quantitative trait locus database were identified and shown to be related to fat deposition. The expression of five DE lncRNAs and mRNAs was verified by quantitative real time polymerase chain reaction (qRT-PCR). The results of qRT-PCR and RNA-sequencing were consistent. Conclusion: These results demonstrated that the different IMF contents among pig individuals may be due to the DE lncRNAs and mRNAs associated with lipid droplets and fat deposition.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.05a
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• pp.262-265
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• 2004