Why the need for animal models? Flashcards
Definition - model organism
Non-human species extensively studied to understand a biological phenomenon
What have been conserved between humans and animal models that make their use possible?
Metabolic and developmental pathways are highly conserved
Why are particular models chosen?
Chance - models prevalent and around at the time
Easy genetic manipulation - mutations easily induced
Short life cycle
Cost - cheap to upkeep
Easy analysis of disease traits
Inbreeding of populations - useful in rapid genomic sequencing and Reduced genetic variation
What are the relevant/commonly used models and why are they used?
Conservation of metabolic and developmental pathways
FISH, MOUSE, CHICK AND FLY
GxE Interactions -relevance? Why important in animal models?
GENOTYPES drive development and phenotypes in combination with PHENOTYPES.
Animals can have their genomes sequenced and examined in large numbers
GWAs - what are they and what are they used for? Limitations of the technique?
Genome wide association studies - SNPs are measured (gene variant in particular part of the genome) in 2 patients with a particular disease. - Genetic cause???
BUT correlation not always causation.
Limitation - don’t show when or where a gene is expressed. Doesn’t show how the protein being coded triggers a disease
L.O.F / G.O.F studies - what are they and why are they useful
Allows us to decipher the function of a cell or protein product
Conditional knockout - how does it work?
Transgenic mouse is carrying a floxed allele (allele floxed in EVERY CELL) –> bred with mouse carrying Cre recombinase at a tissue-specific promoter –> bred and gene cut out in that particular tissue.
Methods of visualisation of cells and proteins
In situ hybridisation (mRNA) and Immunohistochemistry (proteins) - tell us where and when a gene is expressed
Reporter lines - what and why important?
Can follow an individual line of cells to report their expression. Lines of cells can be visualised IN REAL TIME!!!!!!
FASC - Fluorescence activated cell sorting - what is it and what can it tell us?
Allows isolation of labelled cells.
Useful after drug administration.
Can tell us: if a cell is proliferating, if a cell is secreting a hormone, if a cell is responding to a signal
WHAT HAVE ANIMAL MODELS HELPED US ACHIEVE ?
- Toxicity testing -identification of signalling pathways -identification of abnormal cellular outputs - demonstrated disease progression
Whole organisms analysis - what does it allow?
Allows understanding of the interactions between different components of an organism
