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Archive - Feb 12, 2012

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BGI Researchers Discover Extensive RNA Editing in a Human Transcriptome

In a new study published online on February 12, 2012 in Nature Biotechnology, researchers from China’s BGI, the world's largest genomics organization, reported the evidence of extensive RNA editing in a human cell line by analysis of RNA-seq data, demonstrating the need for new robust methods to identify important post-transcriptional editing events. RNA editing is a normal, but not yet fully understood, process in which small nucleotide changes occur after DNA has been transcribed into RNA. It is an integral step in generating diversity and plasticity of cellular RNA signature as a post-transciptional event that recodes hereditary information. RNA editing is an important area in the post-genomic era for its role in determining protein structure and function. It has become increasingly important in genetic research. Last year, a study published in Science (Li et al. Science, May 19, 2011) reported a large number of sequence differences between mRNA and DNA in the human transcriptome. This finding was startling because it implied that there might be a still undiscovered mechanism of 'RNA editing' that could disrupt the central dogma and affect our understanding of genetic variation. However, this view was strongly contested by other scientists because of the technical issue and lack of academic rigor, such as sequencing error or mis-mapping. In this latest study, BGI researchers developed a more rigorous pipeline for approaching these problems and answered some of the concerned questions, which contributed to paving way for the further studies of this field. The researchers obtained the whole-transcriptome data by RNA-seq from a lymphoblastoid cell line of a male Han Chinese individual (YH), whose genome sequence was previously reported as the first diploid genome of Han Chinese.

Anti-Diabetic Medication Can Prevent Long-Term Effects of Maternal Obesity

In a study presented February 11, 2012 at the Society for Maternal-Fetal Medicine's annual meeting, The Pregnancy Meeting ™, in Dallas, Texas, researchers reported findings that show that short therapy with the anti-diabetic medication Pioglitazone can prevent the long-term effects of maternal obesity on offspring. This study, “Pioglitazone Therapy in Offspring Exposed to Maternal Obesity,” is the first step toward the long-term goal of preventing metabolic syndrome and obesity in children secondary to maternal obesity. The data proposes a potential role for drugs that activate peroxisome proliferator-activated receptors in the prevention of metabolic syndrome in adult offspring of obese mothers. "Obesity in children, which is on the rise, predisposes them to lifelong diseases such as diabetes, high lipid levels, hypertension, and cardiac diseases," said Dr. Egle Bytautiene, with The University of Texas Medical Branch, Obstetrics and Gynecology, Galveston, Texas, and one of the study's authors. "A large part of obesity in children is programmed during pregnancy and our study shows that a drug used to treat diabetes in adults can prevent the long-term effects of maternal obesity on the offspring, even when used for a short period of time after birth." Dr. Bytautiene and her colleagues placed mice on a high-fat diet for three months prior to, and during pregnancy. The resulting pups were weaned to a regular diet. Pups were randomly selected to receive Pioglitazone or a placebo. Treatment was given once daily from 10 to 12 weeks of age. Immediately before and after the treatment period, the offspring were weighed, their visceral adipose tissue was evaluated using computed-tomography, blood was collected for fasting glucose and triglyceride analysis, and intraperitoneal glucose tolerance tests were performed.