title: Space/population and time/age in DNA methylation variability in humans: a study on IGF2/H19 locus in different Italian populations and in mono- and di-zygotic twins of different age.
abstract: Little is known about the impact of space (geography/ancestry) and time (age of the individuals) on DNA methylation variability in humans. We investigated DNA methylation of the imprinted IGF2/H19 locus in: i) a cohort of individuals homogeneous for age and gender (males with restricted age range: 30-50 years) belonging to four Italian districts representative of the major genetic clines, informative for the geographical dimension; ii) a cohort of monozygotic (MZ) and dizygotic (DZ) twins of different ages (age-range: 22-97 years), informative for the temporal dimension. DNA methylation of the analyzed regions displayed high levels of inter-individual variability that could not be ascribed to any geographical cline. In MZ twins we identified two IGF2/H19 regions where the intra-couple variations significantly increased after the age of 60 years. The analysis of twins' individual life histories suggests that the within twin pairs difference is likely the result of the aging process itself, as sharing a common environment for long periods had no effect on DNA methylation divergence. On the whole, the data here reported suggest that: i) aging more than population genetics is responsible for the inter-individual variability in DNA methylation patterns in humans; ii) DNA methylation variability appears to be highly region-specific.
authors.affiliation: CIG - Interdipartimental Center L. Galvani, University of Bologna, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Pirazzini
authors.forename: Cristina
authors.initials: C
authors.lastname: Giuliani
authors.forename: Maria G
authors.initials: MG
authors.lastname: Bacalini
authors.forename: Alessio
authors.initials: A
authors.lastname: Boattini
authors.forename: Miriam
authors.initials: M
authors.lastname: Capri
authors.forename: Elisa
authors.initials: E
authors.lastname: Fontanesi
authors.forename: Elena
authors.initials: E
authors.lastname: Marasco
authors.forename: Vilma
authors.initials: V
authors.lastname: Mantovani
authors.forename: Michela
authors.initials: M
authors.lastname: Pierini
authors.forename: Elisa
authors.initials: E
authors.lastname: Pini
authors.forename: Donata
authors.initials: D
authors.lastname: Luiselli
authors.forename: Claudio
authors.initials: C
authors.lastname: Franceschi
authors.forename: Paolo
authors.initials: P
authors.lastname: Garagnani
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism*; D019175:DNA Methylation; D004777:Environment; D005260:Female; D005843:Geography; D006801:Humans; D007335:Insulin-Like Growth Factor II / Q000235:genetics*; D007558:Italy; D008297:Male; D008875:Middle Aged; D062085:RNA, Long Noncoding / Q000235:genetics*; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics; D055815:Young Adult
chemical_list: C094335:H19 long non-coding RNA; C035170:IGF2 protein, human; D062085:RNA, Long Noncoding; D007335:Insulin-Like Growth Factor II