C/EBPb converts bovine fibroblasts to adipocytes without hormone cocktail induction

BACKGROUND: Adipogenesis and fibrogenesis can be considered as a competitive process in muscle, which may affect the intramuscular fat deposition. The CCAAT/enhancer-binding protein beta (C/EBPb) plays an important role in adipogenesis, which is well-characterized in mice, but little known in bovine so far. RESULTS: In this study, real-time qPCR revealed that the level of C/EBPb was increased during the developmental stages of bovine and adipogenesis process of preadipocytes. Overexpression of C/EBPb promoted bovine fibroblast proliferation through mitotic clonal expansion (MCE), a necessary process for initiating adipogenesis, by significantly downregulating levels of p21 and p27 (p < 0.01). Also, the PPARc expression was inhibited during the MCE stage (p < 0.01). 31.28% of transfected fibroblasts adopted lipid-laden adipocyte morphology after 8 d. Real-time qPCR showed that C/EBPb activated the transcription of early stage adipogenesis markers C/EBPa and PPARc. Expression of ACCa, FASN, FABP4 and LPL was also significantly upregulated, while the expression of LEPR was weakened. CONCLUSIONS: It was concluded C/EBPb can convert bovine fibroblasts into adipocytes without hormone induction by initiating the MCE process and promoting adipogenic genes expression, which may provide new insights into the potential functions of C/EBPb in regulating intramuscular fat deposition in beef cattle.

Identification of genetic variants the CCKAR gene and based on body measurement and carcass quality characteristics in Qinchuan beef cattle (Bos taurus)

BACKGROUND: This study aimed to explore genetic polymorphisms of the CCKAR gene and their relationship with the growth and development of Qinchuan cattle which could be used as molecular markers for the improvement of the breeding of Qinchuan cattle. RESULTS: Here, we have identified seven single nucleotide polymorphisms (SNPs) at loci g. 1463 C>G; g. 1532 T>A; g. 1570 G>A; g. 1594 C>A; g. 1640 T>C; g. 1677 G>C; and g. 1735 C>T in the coding region of the bovine CCKAR gene. The frequencies identified on allelic and genotypic characteristics have shown that all seven SNPs diverged from the Hardy-Weinberg-Equilibrium. The SNP2, SNP3, SNP6 and SNP7 had the lowest polymorphism information content values, and remaining SNPs were found to be moderate (0.25 < PIC < 0.50). The genotype CG in SNP1 at loci g.1463 C>G had the greatest association with WH, HW, CD and CCF, while the genotype TA at the very same loci was associated with BFT, ULA and IMF content in Qinchuan cattle. The CCKAR gene expression level in adipose tissue, small intestine, liver and skeleton muscle was found to be higher, whereas, the expression level of mRNA in organs of other digestive system including reticulum, abomasum and omasum was moderate. Some expression of CCKAR mRNA was found in the large intestine, kidney and rumen. CONCLUSIONS: In summary, our finding suggested that the CCKAR gene could be used as a potential candidate for the improvement of carcass quality and body measurements of Qinchuan cattle.

Transcriptome profiling reveals differential expression of genes potentially involved in muscle and adipose tissue development of cattle

BACKGROUND: To identify differentially expressed genes (DEGs) between muscle and adipose in cattle, we analyzed the data from the RNA sequencing of three Angus×Qinchuan crossbred cattle. RESULTS: Searched the Gene Expression Omnibus (GEO) for a microarray dataset of Yan yellow cattle, GSE49992. After the DEGs were identified, we used STRING and Cytoscape to construct a protein­protein interaction (PPI) network, subsequently analyzing the major modules of key genes. In total, 340 DEGs were discovered, including 21 hub genes, which were mainly enriched in muscle contraction, skeletal muscle contraction, troponin complex, lipid particle, Z disc, tropomyosin binding, and actin filament binding. CONCLUSIONS: In summary, these genes can be regarded as candidate biomarkers for the regulation of muscle and adipose development.

Expression profiles and polymorphism analysis of CDIPT gene on Qinchuan cattle

Background CDIPT (CDP-diacylglycerol-inositol 3-phosphatidyltransferase, EC 2.7.8.11) was found on the cytoplasmic side of the Golgi apparatus and the endoplasmic reticulum. It was an integral membrane protein performing the last step in the de novo biosynthesis of phosphatidylinositol (PtdIns). In recent years, PtdIns has been considered to play an essential role in energy metabolism, fatty acid metabolic pathway and intracellular signal transduction in eukaryotic cells. Results In this study, the results of real-time polymerase chain reaction (PCR) showed that the expression of CDIPT gene was remarkably different in diverse tissues. We also detected the polymorphism of bovine CDIPT gene and analyzed its association with body measurement and meat quality traits of Qinchuan cattle. Blood samples were obtained from 638 Qinchuan cattle aged from 18 to 24 months. DNA sequencing and PCR-restriction fragment length polymorphism (RFLP) were used to find CDIPT gene single nucleotide polymorphism (SNP). Three SNPs g.244T>C (NCBI: rs42069760), g.1496G>A and g.1514G>A were found in this study. g.244T>C located at 5'untranslated region (5'UTR) of exon 1 showed three genotypes: TT, TC and CC. g.1496G>A and g.1514G>A detected the first time were located in intron 3 and showed the same genotypes: GG, GA and AA. Conclusions Analysis results showed that these three SNPs were significantly associated with body measurement traits (BMTs) and meat quality traits (MQTs). We suggested that CDIPT gene may have potential effects on BMTs and MQTs and can be used for marker-assisted selection.

Polymorphisms of the bovine chemokine receptor-like 1 gene and their associations with meat quality traits in Qinchuan cattle (Bos taurus)

Background: We investigated the polymorphisms of the bovine chemokine receptor-like 1(CMKLR1) gene. The coding region of CMKLR1 was screened in Qinchuan cattle by PCR-RFLP technology. Results: In this study, we discovered two single nucleotide polymorphisms (SNPs) (264G > C and 762C > T) in the coding region of the CMKLR1 gene. Hence, we described the BmgT120l and Pdm1 PCR-RFLP methods for detecting the 64G > C and 762C > T mutations, respectively. PCR-RFLP and sequencing were used to analyze the two loci of CMKLR1 gene in 324 individuals, which were randomly selected from breeding populations. Furthermore, meat quality traits in another 80 Qinchuan individuals were analyzed by the comparison between the genotypes and their phenotypic data. Conclusions: The results showed that the G264C SNP and C762T SNP of bovine CMKLR1 were significantly associated with backfat thickness (BFT) and water holding capacity (WHC), respectively.