cycle 11 Flashcards
definition of epigenetics
how behaviours and environment can cause changes in genes.
difference between genome and epigenome
genome is entire genetic sequence, epigenome is chemical mods and protein interactions that regulate gene expression without altering DNA sequence
epigenome of twins
identical genomes, very different epigenome with age
epigenetic drift
epigenetic modifications that occur with age
know how DNA is methylated, demethylated and what effects this has on gene expression
methylation - addition of methyl group (CH3) to cytosine base of DNA at CpG. inactivates transcription
demethylation - removal of methyl groups from DNA. activates transcription
know how histones are acetylated, deacetylated, and what effects this has on gene expression
acetylation - addition of acetyl group (CH3CO) to lysine structure. makes DNA more accessible (euchromatin - loose formation) to TFs, RNA polymerase, etc. activates gene, promotes gene expression
deacetylation - removal of acetyl groups, makes DNA less accessible (heterochromatin - tight structure), inactivates gene, leads to gene repression
definition of heterochomatin and euchromatin
heterochromatin - tight structure, lysine +
euchromatin - loose formation, lysine 0
behavioural genetics - relationship between grooming/licking, anxiety, corticosterone, glucocorticoid receptors, methylation of promoter and gene expression
low licking/grooming - hypermethylated, inactivates transcription, decreases GR expression, high corticosterone levels, high anxiety
high licking/grooming - no methylation, increases GR expression, low corticosterone levels, low anxiety
meaning of transgenerational epigenetic inheritance
early life experiences can have an effect o the epigenome, can be inherited by offspring
various human diseases, disorders, behaviours that are linked to epigenetics
schizophrenia, anxiety, drug addiction, depression
increase in HDACS can lead to:
increase in deacetylation of histones, decrease in transcription, increase in heterochromatin state
chronological vs biological age
epigenetic clock - biomarker for diseases
epigenetic age acceleration
