1. Epigenetic differences arise during the lifetime of monozygotic twins.
- Author
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Fraga MF, Ballestar E, Paz MF, Ropero S, Setien F, Ballestar ML, Heine-Suñer D, Cigudosa JC, Urioste M, Benitez J, Boix-Chornet M, Sanchez-Aguilera A, Ling C, Carlsson E, Poulsen P, Vaag A, Stephan Z, Spector TD, Wu YZ, Plass C, and Esteller M
- Subjects
- 5-Methylcytosine metabolism, Acetylation, Adult, Analysis of Variance, Electrophoresis, Capillary, Female, Humans, Male, Nucleic Acid Amplification Techniques, Oligonucleotide Array Sequence Analysis, Restriction Mapping, Reverse Transcriptase Polymerase Chain Reaction, Sequence Analysis, DNA, Spain, Surveys and Questionnaires, Twins, Monozygotic metabolism, Twins, Monozygotic physiology, X Chromosome Inactivation genetics, DNA Methylation, Epigenesis, Genetic genetics, Gene Expression Regulation, Developmental, Histones metabolism, Phenotype, Twins, Monozygotic genetics
- 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.
- Published
- 2005
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