Lecture 11 Flashcards
Q-PCR.
Looking at mRNA and how they change in response to a particular condition.
Microarray analysis.
Look at messenger RNA in the cell.
RNA-seq.
Provides sequence information and relative abundance of the transcripts.
Proteomic analysis.
Looking at proteins, not mRNA. Qualitative: what kinds of protein are there. Quantitative: cam also be determined.
Levels in genes.
Genes to transcriptome to proteome.
Natural transgenesis.
The entire gene from another organism, without modification, is inserted into the model.
Synthetic DNA.
Directing the expression of a gene to specific tissue using tissue-spefcific types of promoters.
Over-expression of LDL receptors in mice.
They make more LDL receptors. This means that there is a smaller amount of lipoproteins in the blood even in the case of high fat diets. However, why do transgenic mice show a decrease in HDL? There is not much cholesterol in the peripheral tissues, so HDL does not accumulate to an appreciable amount.
How can you separate lipoproteins?
By size.
Increased expression of LDL receptors in mice.
Provides a resistance to diet-induced hypercholesterolemia. It is a gain of function modification.
Global modification.
The gene can be “knocked-out” of the entire animal.
Local modification.
The gene is “knocked-out” of specific tissues or cells.
Expression of genes can be “knocked-down” over a developmental period.
Example: expression of lactase in humans.
What does a fertilized egg normally turn into?
A blastocyst.
Embryonic stem cells.
They require support of blastocysts that produce growth factors. LIF (hormone) prevents differentiation of the embryonic stem cells. We can take the ES cells and put them into new blastocysts because they are totipotent; the modification can then be propagated for generations.
LIF (a hormone).
Prevents differentiation of stem cells.
Why are embryonic stem cells useful?
They are totipotent.
Chimera.
One animal made from 2 genomes.
Size comparison of blastocysts and zygotes.
Blastocysts are bigger than zygotes.
Pedigree.
Tells you how genes are inherited.
LXR alpha.
Expressed in tissues and important for homeostasis.
Importance of LRX alpha on lipid metabolism.
Activated by oxysterols; controls the expression of many genes involved in sterol and fat metabolism.
Hepatic lipids.
Lipids in the liver.
LXR alpha disruption and its effect on hepatic lipids.
There is a large accumulation of cholesterol in the liver.
SREBPs and LXR.
LXR targets SREBPs. LXR will increase SREBP-1c gene expression, which stimulates genes involved in fatty acid metabolism and triacylglycerol.
Reduction in expression of SREBP-2.
Embryonic lethal; cells cannot survive. SREBP-2 is more important in development.
NPC1L1
Binds to the apical surface of enterocytes.
Knock-out of NPC1L1 in mice compared to ezetimibe presence.
It does not completely eliminate the absorption of bile acids; this means that NPC1L1 catalyzes the absorption most cholesterol. Ezetimibe almost completely inhibits all activity of NPC1L1.
Nutrition and the individual.
There is an optimal level for nutrition of each individual, and that depends on the composition of genes of that individual.
Scope of nutrition.
Cellular function through development all the way to adulthood and on.
-Omics.
Methodology used to design optimal nutrition strategies.
