Zusammenfassung der Ressource
Epigenetics
- DNA Methylation
- Transcription repressed
- no gene expression
- Histone Modification
- Transcription repressed
- No gene expression
- heritable traits NOT caused by
change in DNA sequence
- Integrated with genes and environment
- Ancestors' nutrition was indicated as the main
influence on longevity through unspecified
epigenetic mechanisms of inheritance.
- Dutch famine example
- children of mothers exposed to famine before
conception had lowest degree of methylation
- Environmental factors such as
socioeconomic status can raise
stress levels
- being poor affects cortisol
- Low maternal warmth contributes to
stress, but high levels of maternal
warmth can be protective factors
- Paternal obesity is
associated with IGF2
hypomethylation in
newborns
- heavier fathers--> percent
methylation drops for children
- increased body weight in children
- Common Disease Genetic and
Epigenetic (CDGE) Hypothesis
- in addition to genetic variation, epigenetics
provides an added layer of variation that
might mediate the relationship between
genotype and internal and external
environmental factors
- Match-mismatch paradigm of disease involves epigenetic
mechanisms of gene regulation. Baby in utero receives cues from
mother about its future environment, and modifies metabolism
among other things. Mismatch occurs when the anticipated
environment differs from reality
- Permanent gene expression changes
- Phenotype affected later in life
- obesity, Type 2 Diabetes,
psychiatric disorders, cancer, etc.
consequences of match-mismatch
- Example: stress of mother leads to
increased insulin, cortisol, and higher
blood pressure
- DNA Acetylation
- Transcription facilitated
- gene expressed