Association of DNA Methylation Levels with Tissue-specific Expression of Adipogenic and Lipogenic Genes in Longissimus dorsi Muscle of Korean Cattle

Abstract

Epigenetic factors, such as DNA methylation status, may regulate adipogenesis and lipogenesis, thus affecting intramuscular fat (IMF) deposition in longissimus dorsi muscle (LM) of beef cattle. In Korean cattle steers, the LM consists mainly of muscle tissue. However, the LM tissue also contains IMF. We compared the gene expression levels between the IMF and muscle portions of the LM after tissue separation. Real-time polymerase chain reaction analysis showed that the mRNA levels of both adipogenic peroxisome proliferator-activated receptor gamma isoform 1 (PPARG1) and lipogenic fatty acid binding protein 4 (FABP4) were higher (p<0.01) in the IMF than in the muscle portion of the LM. We determined DNA methylation levels of regulatory regions of the PPARG1 and FABP4 genes by pyrosequencing of genomic DNA. DNA methylation levels of two of three CpG sites in the PPARG1 gene promoter region were lower (p<0.05) in the IMF than in the muscle portion of the LM. DNA methylation levels of all five CpG sites from the FABP4 gene promoter region were also lower (p<0.001) in the IMF than in the muscle portion. Thus, mRNA levels of both PPARG1 and FABP4 genes were inversely correlated with DNA methylation levels in regulatory regions of CpG sites of the corresponding gene. Our findings suggest that DNA methylation status regulates tissue-specific expression of adipogenic and lipogenic genes in the IMF and muscle portions of LM tissue in Korean cattle.

Genetic, management, and nutritional factors affecting intramuscular fat deposition in beef cattle — A review

“…Understanding the factors affecting IMF deposition and the mechanisms responsible for its deposition is important when manipulating IMF deposition. Our laboratory has studied IMF deposition for more than a decade to understand the mechanisms responsible for IMF deposition in beef cattle [ 6 – 12 ], and we have reviewed molecular mechanisms responsible for IMF deposition in cattle [ 13 ].…”

Effects of Dietary Restriction on the Expression of Lipid Metabolism and Growth Hormone Signaling Genes in the <i>Longissimus dorsi</i> Muscle of Korean Cattle Steers

“…Furthermore, DR did not affect the expression of several genes for lipogenesis (fatty acid-binding protein 4) and adipogenesis (peroxisome proliferator-activated receptor gamma and CCAAT/enhancer binding protein alpha) at both P1 and P2. Korean cattle steers accumulated significantly more body fat ( Bong et al, 2012 ; Baik et al, 2014 ). In our previous studies, bulls and steers had differential gene expression patterns for lipid metabolism, lipogenesis, and adipogenesis in the LM ( Bong et al, 2012 ; Jeong et al, 2013a , b ; Ahn et al, 2014 ; Baik et al, 2014 ).…”

“…Korean cattle steers accumulated significantly more body fat ( Bong et al, 2012 ; Baik et al, 2014 ). In our previous studies, bulls and steers had differential gene expression patterns for lipid metabolism, lipogenesis, and adipogenesis in the LM ( Bong et al, 2012 ; Jeong et al, 2013a , b ; Ahn et al, 2014 ; Baik et al, 2014 ). Our study demonstrates that DR has minor effects on the expression of genes for lipid metabolism in the LM.…”

Epigenetic marks: regulators of livestock phenotypes and conceivable sources of missing variation in livestock improvement programs

“…Examination of DNA methylation in adipose and muscle tissues of pigs showed that differentially methylated regions in gene promoters were highly associated with the development of obesity through repression of both known obesity-related genes and novel genes ( Li et al, 2012d ). Recently, Baik et al (2014) observed that DNA methylation status regulated tissue-specific expression of adipogenic and lipogenic genes in the intramuscular fat and longissimus dorsi muscle tissue in Korean cattle.…”