Flashcards in Cardiovascular Health Lecture 2.2 : Interrogating the Coding and Non - Coding Genome Deck (21):
What percentage of genes and environment contribute to blood pressure?
~30% from genes, and ~70% from environment.
What is genomics? What does it use to predict shit?
Looking at genes, explaining genetic causes and mechanisms of disease. Can predict using biomarkers.
What is the most common genetic variation?
Single nucleotide polymorphisms
What are SNPs?
Changes in DNA at one base pair.
Where can SNPs occur?
Both coding and non coding regions.
How can SNPs be used in relation to dieases? Give an example.
Look at SNP of 2k people with no diease (hypertension)
Do the same with 2k people with disease.
Compare SNP prevalence percentages to form an assocation.
How can SNPs be analysed?
Using microarrays, which is covered by SNPs.
Amplify genome, fragment and allow to anneal.
Besides an assocation with disease, what else can SNPs tell us?
Can associate a disease to a locon/chromosomal location.
What needs to be done to form a strong association using SNPs?
A lot of data is obtained using SnPs, so a very strict p-value is needed to remove false positives.
What percentage of the total heritability does SNPs contribute to? What does this suggest?
Only ~10%. Suggests other factors are aside from SNPs are at play, such as gene expression differences and epigenetics.
What is a copy number variation? What percentage of the genome do they account for?
Large segments of DNA that are bulk changes to the DNA. Account for up to 12%.
Give an example of a copy number variation.
4 segments - ABCD - normal
CNV is ABBCD
one segment is repeated, can also be deleted
How are copy number variations detected, and how do they appear?
Duplicated segments appear brighter while deletions are less so, or an absence.
What are two forms of non-coding RNA?
lncRNA - long
miRNA - small
what are the functions of non-coding RNAs?
Full function not known, but might be involved in chromatin maintenance and DNA folding, as well as splicing and DNA editing.
What is needed to study RNA effects?
Tissue of the associated region.
ie. to study hypertension/bp, kidney tissue needed.
Can RNA be sequenced?
Yes, reverse transcriptase, to form cDNA.
Can RNA expression levels be detected?
Yes, microarrays. Intensity of dots suggest expression levels.
How big are miRNAs and where are they found?
20bp long, and float freely in the nucleus. Also found in plasma.
What do miRNA bind to? What do they do?
They bind to mRNA via complementarity and can degrade it as a signalling molecule, but can also block translation.