title: Epigenetic differences arise during the lifetime of monozygotic twins.
abstract: Monozygous twins share a common genotype. However, most monozygotic twin pairs are not identical; several types of phenotypic discordance may be observed, such as differences in susceptibilities to disease and a wide range of anthropomorphic features. There are several possible explanations for these observations, but one is the existence of epigenetic differences. To address this issue, we examined the global and locus-specific differences in DNA methylation and histone acetylation of a large cohort of monozygotic twins. We found that, although twins are epigenetically indistinguishable during the early years of life, older monozygous twins exhibited remarkable differences in their overall content and genomic distribution of 5-methylcytosine DNA and histone acetylation, affecting their gene-expression portrait. These findings indicate how an appreciation of epigenetics is missing from our understanding of how different phenotypes can be originated from the same genotype.
authors: Epigenetics Laboratory, Spanish National Cancer Centre (CNIO), Melchor Fernandez Almagro 3, 28029 Madrid, Spain.
authors: Mario F
authors: MF
authors: Fraga
authors: Esteban
authors: E
authors: Ballestar
authors: Maria F
authors: MF
authors: Paz
authors: Santiago
authors: S
authors: Ropero
authors: Fernando
authors: F
authors: Setien
authors: Maria L
authors: ML
authors: Ballestar
authors: Damia
authors: D
authors: Heine-Suñer
authors: Juan C
authors: JC
authors: Cigudosa
authors: Miguel
authors: M
authors: Urioste
authors: Javier
authors: J
authors: Benitez
authors: Manuel
authors: M
authors: Boix-Chornet
authors: Abel
authors: A
authors: Sanchez-Aguilera
authors: Charlotte
authors: C
authors: Ling
authors: Emma
authors: E
authors: Carlsson
authors: Pernille
authors: P
authors: Poulsen
authors: Allan
authors: A
authors: Vaag
authors: Zarko
authors: Z
authors: Stephan
authors: Tim D
authors: TD
authors: Spector
authors: Yue-Zhong
authors: YZ
authors: Wu
authors: Christoph
authors: C
authors: Plass
authors: Manel
authors: M
authors: Esteller
mesh_terms: D044503:5-Methylcytosine / Q000378:metabolism; D000107:Acetylation; D000328:Adult; D000704:Analysis of Variance; D019175:DNA Methylation; D019075:Electrophoresis, Capillary; D044127:Epigenesis, Genetic / Q000235:genetics*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006657:Histones / Q000378:metabolism*; D006801:Humans; D008297:Male; D021141:Nucleic Acid Amplification Techniques; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D015183:Restriction Mapping; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013030:Spain; D011795:Surveys and Questionnaires; D014430:Twins, Monozygotic / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D049951:X Chromosome Inactivation / Q000235:genetics
chemical_list: D006657:Histones; D044503:5-Methylcytosine