Epigenetic Variation in Monozygotic Twins: A Genome-Wide Analysis of DNA Methylation in Buccal Cells

Genes

Jenny van Dongen²  Erik A. Ehli³  Roderick C. Slieker¹  Meike Bartels²  Zachary M. Weber³  Gareth E. Davies³  P. Eline Slagboom¹  Bastiaan T. Heijmans¹ 

[1] Department of Molecular Epidemiology, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands; E-Mails:;Department of Biological Psychology, VU University Amsterdam, Van der Boechorststraat 1, 1081 BT Amsterdam, The Netherlands; E-Mails:;Avera Institute for Human Genetics, 3720 W. 69th Street, Sioux Falls, SD 57108, USA; E-Mails:

关键词: DNA methylation;    cytosine;    epigenetics;    Illumina 450k;    twin study;    buccal epithelium;    genome-wide methylation;    children;   

DOI  :  10.3390/genes5020347

来源: mdpi

【 摘 要 】

DNA methylation is one of the most extensively studied epigenetic marks in humans. Yet, it is largely unknown what causes variation in DNA methylation between individuals. The comparison of DNA methylation profiles of monozygotic (MZ) twins offers a unique experimental design to examine the extent to which such variation is related to individual-specific environmental influences and stochastic events or to familial factors (DNA sequence and shared environment). We measured genome-wide DNA methylation in buccal samples from ten MZ pairs (age 8–19) using the Illumina 450k array and examined twin correlations for methylation level at 420,921 CpGs after QC. After selecting CpGs showing the most variation in the methylation level between subjects, the mean genome-wide correlation (rho) was 0.54. The correlation was higher, on average, for CpGs within CpG islands (CGIs), compared to CGI shores, shelves and non-CGI regions, particularly at hypomethylated CpGs. This finding suggests that individual-specific environmental and stochastic influences account for more variation in DNA methylation in CpG-poor regions. Our findings also indicate that it is worthwhile to examine heritable and shared environmental influences on buccal DNA methylation in larger studies that also include dizygotic twins.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.