[Methylation status of pig adiponectin promoter and its expression].

Adiponectin, a cytokine hormone secreted exclusively by adipose tissue, has key roles in energy homeostasis and in metabolism of glucose and lipid. Adiponectin expression was negatively associated with obesity. Many CpG sites were found at the adiponectin promoter region (nucleotides -1500 approximately -1350 bp). To further understand the regulation of pig adiponectin expression, the methylation status of pig adiponectin promoter and its mRNA expression were analyzed by methylation special PCR (MSP) and real-time PCR. At the adiponectin promoter region where CG enriches (nucleotides -1500 approximately -1350 bp), the percentage of demethylation in Changbai pigs was 83%; and the percentages of demethylation in Lantang pigs at 90-day-old and adult stages were 33% and 100%, respectively. The process of methylation and demethyla-tion mainly occurred in certain CpG sites. In muscle tissues, the promoter hypermethylation status of adiponectin gene was detected, which was consistent with the expression of this gene. These results suggested that the methylation of this gene experienced a dynamic process, with the development of individuals, which agreed with the fluctuating trend of gene expression.