Intro to animal models in research

Question 1

What is the difference between in vitro and in vivo research?

Answer 1

In vivo: experimental procedure done in a living organism

in vitro: experimental procedure done within the confines of a test tube/flask/plate

Question 2

What are the advantages/disadvantages of in vivo and vitro research?

Answer 2

in vivo:

• expensive
• Involves the use of lab animals - or humans

in vitro:

• reduced cost
• Allow the tight control of physio-chemical environment
• Animal use is very reduced
• Often difficult to replicate the conditions cells encounter in a living organism
• systemic effects cannot be tested

Both approaches are complementary

Question 3

What are the desirable characteristics of a model organism?

Answer 3

Relevance/representative
Accessibility/availability
Experimental manipulation
Genetics
Cost/space

Question 4

What are the most widely used models?

Answer 4

Homo sapiens
Mus musculus (mouse)
Danio rerio (Zebrafish)
Xenopus Laevis/tropicalis (frog)
Gallus gallus (chicken)

Question 5

Why is the zebrafish used as a model system?

Answer 5

External fertilisation/embryos - allows for easy manipulation
fast development
transparent embryos - can visualise development
genome completely sequenced
extensive genomic/transgenesis tools
allows high-throughput approaches
amenability to embryological and imaging approaches
cheap

Question 6

what are some advantages of a mouse model?

Answer 6

share higher degree of homology with humans (mouse genome similar to human)
multiply quickly
short generation time - so several generations can be measured at once
wide availability
easy to house due to size (Small)
short lifespan so scientists can measure effects of ageing