Yeast Biotechnology Flashcards
Why is yeast such a good model microorganism?
- It has a lot of functional conservation.
- Many homologous genes (eg. 40% of disease genes in humans have a homologue in Yeast).
- It can ferment as well as respire.
- Its cell cycle is similar to the human cell cycle so can model cancer etc. - it is also easy to observe.
What is transcriptomics?
The study of analysing an organisms transcriptome (sum of its RNA transcripts).
It is used to determine how cells function and how they differ from eachother.
This allows you to understand things like how cancer is made etc.
What did Ross-Macdonald do in 1999?
He did transposon mutagenesis in yeast.
There are two transposons in yeast (Ty1 and Ty2).
He mutated a transposon so it contained a reporter gene (LacZ) and haemagglutinin (made the protein have antibodies so you can track where the protein goes).
What did Winzeler do in 1999?
He made ~6,000 yeast mutants, each with a different gene knocked out.
This allows us to find the essential genes (mutants who don’t have the genes die) and to test for drug resistant mutants for example.
Each gene was given a barcode tag so you can monitor the abundance of each mutant in a mixed culture.
What kind of yeast gives a clue to the evolution of multicellularity?
Snowflake yeast.
When clumped they evade predators.
Selection pressure caused them to become multicellular.
How can you tell the function of a protein?
You can predict the function of a protein if it interacts with a known protein (they will have similar functions).
What is synthetic lethality?
When two different mutations together give a more severe phenotype than either alone.
-this shows that these genes have roles in a common step.
What did Costanzo do in 2010?
He did ~170,000 mutations and did a hybridisation of all of them. Any one with a growth defect meant that the mutation was a synthetic lethal.
How can you find out if a protein-protein interaction occurs?
Protein chips
Or
Tap-tagging (tandem affinity purification tag). Bands on the tap tag stick allows you to see which proteins have interacted.
What did Gavin do in 2002?
He tap tagged ~1700 yeast ORFs and purified them.
