Drosophila Flashcards
What is the scientific name for fruit flies?
Drosophila melanogaster
True/false: mouse research is 10 times more costly than fly work
True/false: Drosophila and humans share 40% of genes
How many Nobel prizes have been awarded for fly research?
True/false: You can use flies to develop personalized medicine
How many years have Drosophila been used as a model organism?
How long do flies live?
TRUE, FALSE (60%), 6 NPs, TRUE, 6 years, 30+ days
Nobel prize findings (6)
- the role played by chromosomes in heredity
- the production of mutations by means of X-ray irradiation
- The genetic control of early embryonic development
- Odour receptors and the organization of the olfactory system
- The activation of innate immunity (toll mutant Drosophila are susceptible to fungal infection)
- Insights into internal biological clock
Why fly?
1st key: cost-effective and efficient
2nd key: knowledge and infrastructure
3rd key: similarity (about 75% of known human disease genes have a recognizable match in the genome of fruit flies)
How can you modulate the developmental cycle of flies?
-Can speed up developmental cycle at 29 degrees or slow down at 18 degrees
Who is the real lord of the flies?
Thomas Hunt Morgan 1866-1945
- Evolutionary biologist, geneticist, embryologist and an author
- Verified Mendel’s work
- Nobel prize for discoveries elucidating the role that chromosome plays in heredity
- Generated and identified several Drosophila mutants
What did Morgan discover?
white mutants
- Morgan noticed a white-eyed male among red-eyed flies
- Thousands of mutants were identified and named for phenotype
Who is Calvin Bridges (1889-1938)?
Morgan’s student
- Developed ‘fly food’ to replace banana
- His work suggested that genes are carried on chromosomes
- polytene chromosome
Who is Alfred Sturtevant (1891-1970)?
- Used to study his father’s horse pedigrees
- Morgan’s student
- Discovered gene linkage
- Made the first chromosome map
Fly labs back in the day vs now
Morgan’s era had bananas?
Now: stereomicroscopes, vials and bottles, paintbrushes, CO2
Drosophila life cycle stages (4) and roles
embryo: single cell–>cell proliferation, differentiation, organogenesis, segmentation–>multicellular organism
Larva (1,2,3): growth of imaginal discs (50 cells to 100 000 cells, give rise to adult structures ex. wing, eye leg)
Prepupa–>pupa (imaginal discs differentiate into adult structures ex. wing, eye, leg
Adult
Advantages of Drosophila as a model
- Short developmental cycle (~10 days at 25 degree Celsius)
- Cheap and can get large numbers of flies rapidly
- Less genetic redundancy, smaller genomes
- More than 75% of human disease genes have fly homologs!
- Conserved regulatory pathways and processes
- Sophisticated tools to over-express or knock genes out and can do large scale unbiased genetic screens (White/Red screen)
Disadvantage of Drosophila as a model
Disadvantage : maintenance as living cultures only, no permanent conservation (e.g. frozen stocks) possible
What genetics can be studied and how do flies help?
Can study gene structure–>most genes are mapped in flies
Can study gene function–>we can turn genes on and off anytime
Can study gene behaviour in the context of a cell or an organism–>we can turn genes ON or OFF at any space
Drosophila genome was ______.
sequenced
