Lecture 8 Flashcards
study of mechanisms that change gene expression by modifying the DNA without modifying its base sequence
Epigenetics
T or F: In epigenetics, we do not modify the bases, rather we modify the groups attached to them
T
study of the changes in the regulation of gene activity and expression that are not dependent on gene sequence
Epigenetics
Epigenetics is also involved in ___________
development
epigenetics - all the cells are genetically alike but they perform different functions because of
epigenetics
towards maturation, an individual will have different types of cells and different types of tissues but basically they originated from the same zygote.
-modified because of _______
genetics
In epigenetics, different types of tissues will be performing the same tissues, but these tissues came from the original or same ___
zygote
epigenome - wide distribution of epigenetic marks found in the top of the _______
genome
patterns of gene expression in epigenetics are governed by ________
epigenome
they tell which genes to switch on or off in epigenetics
epigenome
these are mechanisms that control accessibility of the genome at right time and place
epigenetic mechanisms
in DNA methylation, addition of methyl in cystosine of ____________ di-nucleotides
5’ - CG - 3’
in DNA methylation, ____ genes are less methylated
(hypermethylated: inactive genes)
active
example of methylation (agouti)
-methylate = ________
-not methylated = _______
methylated = healthy, brown
unmethylated = obese, yellow mouse; at risk for cancers and tumors
takeaway: the presence of the methyl group ______ (trigger, silence the expression for the trait or phenotype
silence
T or F Epigenetic patterns are only determined by epigenome and not by the environment
F: epigenetic patters can be affected by the environment
are epigenetic modifications passed across generations?
Yes; if the diet of the methyl group to earlier generations, then it can be manifested by the offsprings
-mother needs to have a healthy diet because it would affect the offspring
a type of epigentic mechanism that involves of addition of methly group to the histone tails which consequently tightens up DNA thus restricting the transcription factors to access the promotor regions hence allowing or activating TRANSCRIPTION (mawawalan kasi ng barrier which are yung transcription factors)
modification of histones
a type of epigenetic mechanism under the modifcation of histones which involves the addition of acetyl group to histone tails which unravels the DNA making genes more available for activation
acetylation
main difference between methylation and acetylation
methylation would allow for SILENCING of the gene while (MS)
acetylation would allow for EXPRESSION of the gene (
a type of epigenetic mechanism that regulates the stability of your RNA
non-coding RNA
who discovered the non coding RNA epigenetic mechanism
Andrew Z. Fire
Craig C. Mello
(Nobel Prize in 2006 for the discovery of RNA interference (RNAi)
non coding RNA which comes in double stranded form is used to silence the expression of target genes (what mechanism?)
non-coding RNA
two types of RNA that is derived from RNAi
-micro RNA (miRNA)
-short interfering RNA (sirRNA)
when miRNA base pair with specific mRNA does it inhibit or trigger translation?
it inhibits translation
derived from double stranded RNA that may be involved in signalling
apoptosis
cell differentiation
development
miRNAs (micro RNA)
when siRNA base pair with specific mRNA what does it cause?
mRNA degradation
epigenomes can be affected by _______
environmental factors
they improperly turn on and off the genes
environmental factors
T or F: do diet and stress can influence the epigenome of an individual
T
T or F: Prenatal nutrition DOES not affect epigenome
False
ex: Folate is a strong methyl donor that is found in food
-folate for pregnant women can prevent neural tube defects
what day does the neutral tube develops during pregnancy
28th day
pregnant mothers must take what kind of vitamin?
Vitamin B9 or Folic acid (recommended: 400 micrograms of folic acid/day)
4000 micrograms (previous baby with neural tube defects)
can we manipulate epigenetic marks?
YES epigenetic drugs can be developed to treat different illnesses
-these drugs could silence bad genes and turn on good genes
Ex: Drug that can turn on tumor suppressor genes
this process is involved in oxytocin receptor expression
-in autistic children, reduced expression of oxytocin receptor gene due to this process
methylation
T or F drug that can modify methylation of oxytocin receptor gene has a potential to treat autism
True
study on how food affect our genes
nutrigenomics or nutritional genomics
how genetic differences can affect the way we respond to nutrients and other naturally occuring compounds in the food we eat?
foundational question in nutrigenomics
study of molecular relationships between nutrition and response of genes
nutrigenomics
five tenets of nutrigenomics
- diet can be a serious risk factor for a number of dieases
2.gene expression and structure of the human genome can be altered directly or indirectly by the chemicals in our diet - the degree to which diet influences the balance between healthy and disease states may depend on the genetic makeup of an individual
- some diet-regulated genes are likely to play a role in the onset, incidence, progression and or severity of chronic disease
- dietary intervention based on knowledge of nutritional requirement, nutritional status, and genotype can be used to prevent, mitigate or cure chronic diseases
nutrients can reverse or change epigenetic phenoma
such as
DNA methylation
histone modification
nutrition can modify the expression of critical genes associated with
-physiologic and pathologic processes
-embryonic development
-aging
