The latest study was published as a highlighted paper in Nature Communications

May 22, 2012, Shenzhen, China – In a highlighted paper published online in Nature Communications, researchers from Sichuan Agricultural University and BGI, the world's largest genomics organization, reported the atlas of DNA methylomes in porcine adipose and muscle tissues, providing a valuable epigenomic source for obesity prediction and prevention as well as boosting the further development of pig as a model animal for human obesity research.

Obesity could be considered as an epidemic that presents a risk to human health in modern society. It has become an important risk factor for a number of chronic diseases, including diabetes, cardiovascular diseases and cancer. It is predicted that by 2030, about 58% of the world's adult population might be either overweight or obesity, revealing the sever situation of obesity epidemic.

To meet this challenge, researchers worldwide are contributing tremendous efforts on hunting for obesity genes. "Although DNA sequence contains all the information to make who we are, many of the details of our behavior and appearance are actually determined by gene regulation." said Professor Mingzhou Li from Sichuan Agricultural University, "In order to advance obesity research, it is necessary to understand the epigenetic factors, especially DNA methylation, which plays a important role in obesity development."

In this study, researchers took pig as a model. Three breeds of pig were selected, including the Landrace, the Tibetan and the Rongchang pig, to investigate the systematic association between DNA methylation and obesity. The pig is an exceptional restenosis model, and is emerging rapidly as a biomedical model for energy metabolism and obesity in human because of their similarities on metabolic features, cardiovascular systems, and proportional organ sizes.

Adipose tissues (ATs) and skeletal muscle tissues (SMTs) are known to play important roles in the pathogenesis of obesity. Researchers in this study sampled eight ATs and two SMTs from each of the three pig breeds living in comparable environments. 180 methylated DNA immunoprecipitation libraries were developed from the samples, after sequencing with MeDIP-Seq method and data processing, 1,381 Gb data were generated. Based on the epigenomic data, researchers constructed a genome-wide DNA methylation map as well as a gene expression map for adipose and muscle studies.

Through further analysis, researchers found the different methylated regions in promoters, which play a more important role in regulating gene expression and were highly associated with obesity development. Honglong Wu, Project Manager of this project at BGI, said, "We also found that the methylation pattern of IAD (intermuscular adipose) is more similar with that of the VATs (visceral ATs). This finding provides the first epigenomic evidence for IAD as a candidate risk factor for obesity."

Ruiqiang Li, Principal Investigator of this project from Peking University, said, "The work reports the largest dataset of directly sequenced animal DNA methylomes to date, and will serve as a valuable resource for future functional validation, promoting further development of pig as a model organism for human obesity research, as well as maximizing the economic benefits in producing high quality pork."

Professor Xuewei Li from Sichuan Agricultural University, said, "Based on the genomic data associated with DNA methylation, we conducted a comprehensive genome-wide epigenetic survey on ATs and SMTs. I believe our results will lay a solid foundation for exploring epigenetic mechanisms of adipose deposition and muscle growth in the future."

Professor Jun Wang, Executive Director of BGI, said, "Environmental factors can have influences on the way our genes are expressed, making even identical twins different. Rapid advances in the field of epigenetics provide a robust tool for studying gene expression and regulation. Understanding the genetic mechanism of obesity will have a great implication in future development of treatment and therapy."

Sichuan Agricultural University (SICAU) is a university located in Ya'an city, Sichuan province, China and part of the "Project 211", specialized in biotechnology and agricultural sciences, and as well as offering degrees in physical science, engineering, economics, management, veterinary medicine, liberal arts, pedagogy and law.

Its former body was Sichuan Tong Sheng Agricultural School established in 1906, subordinated to National Sichuan University in 1935. It was moved to Yaan city from Chengdu and Sichuan Agricultural College was founded here independently in 1956, renamed as Sichuan Agricultural University in 1985. The university governs 18 colleges, 8 research institutes and several research centers. The university possesses 4 national key disciplines, 14 ministerial and provincial key disciplines, 14 ministerial and provincial key laboratories，2 engineering centers and 3 New Century Invention Group of the State Educational Ministry, 4 post-doctoral programs of first level disciplinary, 49 disciplines with the power to award doctoral degrees, 71 specialized disciplines for masters and 71 for undergraduates. The university, one of the first 200 universities in China entitled to receive overseas students, is active in international academic exchanges with more than 30 universities and research institutes from more than 20 countries. For more information about SICAU, please visit www.sicau.edu.cn

BGI was founded in Beijing, China on September 9th, 1999 with the mission of being a premier scientific partner to the global research community. The goal of BGI is to make leading-edge genomic science highly accessible through its investment in infrastructure that leverages the best available technology, economies of scale, and expert bioinformatics resources. BGI, and its affiliates, BGI Americas, based in Cambridge, MA and BGI Europe, based in Copenhagen. Denmark, have established partnerships and collaborations with leading academic and government research institutions as well as global biotechnology and pharmaceutical companies, supporting a variety of disease, agricultural, environmental, and related applications.

BGI has established a proven track record of excellence, delivering results with high efficiency and accuracy for innovative, high-profile research which has generated over 170 publications in top-tier journals such as Nature and Science. These accomplishments include sequencing one percent of the human genome for the International Human Genome Project, contributing 10 percent to the International Human HapMap Project, carrying out research to combat SARS and German deadly E. coli, playing a key role in the Sino-British Chicken Genome Project, and completing the sequence of the rice genome, the silkworm genome, the first Asian diploid genome, the potato genome, and, most recently, 1000 genomes and human Gut metagenome. For more information about BGI, please visit www.genomics.cn.

新闻来源：http://www.eurekalert.org/pub_releases/2012-05/bs-sau052112.php