Methylation status of <i>VTRNA2-1</i> / <i>nc886</i> is stable across populations, monozygotic twin pairs and in majority of tissues
Saara Marttila, Hely Tamminen, Sonja Rajić, Pashupati P. Mishra, Terho Lehtimäki, Olli T. Raitakari, Mika Kähönen, Laura Kananen, Juulia Jylhävä, Sara Hägg, Thomas Delerue, Annette Peters, Mélanie Waldenberger, Marcus E. Kleber, Winfried März, Riitta Luoto, Jani Raitanen, Elina Sillanpää, Eija K. Laakkonen, Aino Heikkinen, Miina Ollikainen, Emma Raitoharju
Abstract
Aims & methods: The aim of this study was to characterize the methylation level of a polymorphically imprinted gene, VTRNA2-1/nc886, in human populations and somatic tissues.48 datasets, consisting of more than 30 tissues and >30,000 individuals, were used. Results: nc886 methylation status is associated with twin status and ethnic background, but the variation between populations is limited. Monozygotic twin pairs present concordant methylation, whereas ∼30% of dizygotic twin pairs present discordant methylation in the nc886 locus. The methylation levels of nc886 are uniform across somatic tissues, except in cerebellum and skeletal muscle. Conclusion: The nc886 imprint may be established in the oocyte, and, after implantation, the methylation status is stable, excluding a few specific tissues.