Genomics Flashcards
Nutrigenomics
Effect of diet/nutrition on gene expression
-Change in phenotype w/o a change in genotype
Nutrigenetics
Influence of gene variations modifies dietary effects.
- Polymorphisms
- SNP’S
Allele
Genes that have variations in bases
Differentiate between phenotype and genotype
Genotype: Genetic make up (ex.aabb)
Phenotype: physical characteristics
Autosomal recessive genes: Hbs+Hbs
Hb + Hbs
These genes affect RBC shape.
Hbs+Hb = AT heterozygous. Some disc-shaped, some sickle (no symptoms)
Hbs+Hbs = TT homozygous, all RBC are sickle
- Gutamic acid replaced with Valine
SREBP-1c (snp)
Increase fat deposits
High fat + overexpression = dyslipidemia, impaired glucose, T2D
- should be on a low fat diet
Apolipoprotein E4 (snp)
regulates lipoprotein-cholesterol clearance
ApoE4 + High fat = High LDL
- Should be on a low fat diet
How does Mysostatin influence body comp?
It inhibits MPS
Hetero = more fast & muscle
Homo mh = bulky + slow
How does Mysostatin influence body comp?
It inhibits MPS
Hetero = +/mh more fast & muscle
Prader-Willi Syndrome (PWS)
Chromosomal deletion, multi genes affected
Hypothalamic dysfunction, short stature, inappropriate food seeking behaviors, failure to thrive in infancy
Define Epigenetics
heritable changes in gene function that do not involve changes to the underlying DNA sequence. Changes to the DNA molecule itself or to the proteins with which DNA interacts.
Influenced by: Environment, diet, disease, exercise,
Epigenetic examples
DNA methylation
Chromatin modification: modify histones (methylation, phosphorylation, acetylation)
Epigenetic code
Determines what genes are expressed:
DNA methylation + histone modification
Why will two twins never usually be the same?
Epigenome: link between environmental factors and phenotypical changes during the lifetime
What is the life course model
non communicable disease risk will increase due to lifelong exposures with the highest increase during adulthood
Barker hypothesis / Developmental origins of disease hypothesis
There are certain environmental factors that can increase/decrease risk of fetus - suggest improving conditions for a fetus could be effective way to reduce odds of chronic disease.
- Found those with the lowest birth rate had a higher chance of CVD
Intra-uterine growth
associated with increase risk of chronic disease:
SGA/LBW > LGA for chances of chronic disease, LGA is less studied
How did babies during the dutch famine results differ depending on exposure?
DNA methylation changes related to growth
Late - T2D (high glucose)
Early - CVD
Mid - Microalbuminuria / kidney damage
Low protein maternal diet
associated with physical changes in the structure of proteins. (Ex. GLUT 4, leptin, adipose tissue, heat tissue)
choline deficiencies
Brain structure + function
Irreversible
Methyl-group metabolism can be affected by deficiency or supplementations of
Choline, methionine, V B12, folate
Why might the thrifty phenotype model be advantageous
Thrifty model predicts that being born into nutrient poor environment could be advantageous compared to a nutrient rich one which can lead to Met S
