Project description:Background Clenbuterol, a beta-agonist, can dramatically reduce pig adipose accumulation at high dosages. However, it has been banned in pig production because people who eat pig products treated with clenbuterol can be poisoned by the clenbuterol residues. To understand the molecular mechanism for this fat reduction, cDNA microarray, real-time PCR, two-dimensional electrophoresis and mass spectra were used to study the differential gene expression profiles of pig adipose tissues treated with/without clenbuterol. The objective of this research is to identify novel genes and physiological pathways that potentially facilitate clenbuterol induced reduction of adipose accumulation. Results Clenbuterol was found to improve the lean meat percentage about 10 percent (P< 0.5). The adipose cells became smaller and the muscle fibers became thicker with the administration of clenbuterol. The mRNA abundance of 82 genes (ESTs) were found to be statistically differentially expressed based on the Student t-test (P<0.5) in the microarray analyses which containing 3358 genes (ESTs).Theses 82 genes (ESTs) were divided into four groups according to their Gene Ontology Biological Process descriptions. 16 genes were cellular metabolism related genes (including five lipids metabolism related such as apolipoprotein D and apolipoprotein R), 10 were signal transduction related genes, 45 were expressed sequence tags (ESTs) and other 11 others were of various categories. Eleven of the 82 genes (ESTs) were chosen for real-time PCR analysis, with eight of them induced to express similar magnitudes as in the microarray analyses, two could not be detected and one expressed magnitudes that disagreed with the microarray results. Apolipoprotein R was also found to be up-regulated by the proteomic analysis. Conclusions Profound changes were observed in adipose cells after administration of clenbuterol in pigs by histological section and cDNA microarray techniques. The adipose cells became smaller with stimulation by clenbuterol. Changes in mRNA abundance indicated that DNA transcription and protein translation were enhanced in the adipose cells with clenbuterol stimulation. Five lipids metabolism related genes, such as apoD and apoR, were significantly up-regulated. ApoR was up-regulated in both the mRNA transcription and the protein synthesis. ApoR may be one of the critical molecules through which clenbuterol reduces fat accumulation. Keywords: dose response
Project description:Large White and Meishan pigs were either non-treated or injected with mammalian 1-24 ACTH (Immediate Synachten, Novartis France) at the dose of 250 µg per animal. Pigs were sacrificed either immediately after capture from their home cage (non-treated animals) or 1 hour following ACTH injection. Adrenal glands were immediately collected from pigs and frozen on dry ice and then stored at -80°C until RNA isolation. Keywords: stress response, adrenal, gene expression, pig
Project description:Large White and Meishan pigs were either non-treated or injected with mammalian 1-24 ACTH (Immediate Synachten, Novartis France) at the dose of 250 µg per animal. Pigs were sacrificed either immediately after capture from their home cage (non-treated animals) or 1 hour following ACTH injection. Adrenal glands were immediately collected from pigs and frozen on dry ice and then stored at -80°C until RNA isolation. Keywords: stress response, adrenal, gene expression, pig 47 samples
Project description:Clenbuterol-HCL can greatly reduce fat deposition and increase skeletal muscle growth at high dosages. In order to advance our understanding of the fundamental molecular mechanisms, Genechips were used to study the differential gene expression profiles of liver tissues among the pigs with/without Clenbuterol-HCL. Differentially expressed genes identified will be the candidates for further investigations on the molecular mechanisms involved in Clenbuterol-HCL of exerting repartition effects on adipose and skeletal muscle tissue.