Mono-allelic retrotransposon insertion addresses epigenetic transcriptional repression in human genome

• Main Authors: Byun Hyang-Min, Heo Kyu, Mitchell Kasey J, Yang Allen S
• Format: Article
• Language: English
• Published: BMC 2012-02-01
• Series: Journal of Biomedical Science
• Subjects: Epigenetics; Retrotransposons; Long interspersed elements; <it>Alu</it>
• Online Access: http://www.jbiomedsci.com/content/19/1/13

<p>Abstract</p> <p>Background</p> <p>Retrotransposons have been extensively studied in plants and animals and have been shown to have an impact on human genome dynamics and evolution. Their ability to move within genomes gives retrotransposons to affect genome instability.</p> <p>Methods</p> <p>we examined the polymorphic inserted <it>Alu</it>Ya5, evolutionary young <it>Alu</it>, in the progesterone receptor gene to determine the effects of <it>Alu </it>insertion on molecular environment. We used mono-allelic inserted cell lines which carry both <it>Alu</it>-present and <it>Alu</it>-absent alleles. To determine the epigenetic change and gene expression, we performed restriction enzyme digestion, Pyrosequencing, and Chromatin Immunoprecipitation.</p> <p>Results</p> <p>We observed that the polymorphic insertion of evolutionally young <it>Alu </it>causes increasing levels of DNA methylation in the surrounding genomic area and generates inactive histone tail modifications. Consequently the <it>Alu </it>insertion deleteriously inactivates the neighboring gene expression.</p> <p>Conclusion</p> <p>The mono-allelic <it>Alu </it>insertion cell line clearly showed that polymorphic inserted repetitive elements cause the inactivation of neighboring gene expression, bringing aberrant epigenetic changes.</p>