Gene interactions Flashcards
What is annotation?
The determination in total genome sequence of the open reading frames encoding proteins and determination of mRNA transcripts, introns and exons from sequenced genomes.
What is the process of genome annotation?
Determining ORFs and identify the start, stop, and promoter sequences
Assign transcriptosome
Determine numbers and types of regulatory RNAs
Assigning function to genomic sequences
Determine transiently heritable epigenetic modifications that affect gene expression
What is epigenetics?
Heritable changes to DNA expression and its associated proteins that alter gene expression without altering the DNA sequence
What is Gene ontology?
Genes being meaningfully grouped by three categories of likeness
Biological process
Molecular function
Cellular component
Why do we study yeast?
Yeast genetics tools are superior to other organisms and one can use it as a model to understand basic cell biology and develop relevant hypotheses to test in more complex organisms.
What are the characteristics of S. cerevisiae?
Simplest eukaryote Fungus Model cell Short generation time Phototroph Can be frozen Can be replicated Basic, biomedical and industrial applications
Describe yeast mitosis
Start Spindle pole body duplication Bud emergence DNA replication Nuclear migration Spindle formation Chromosome segregation Nuclear division Cytokinesis Growth
What is epistasis?
Where the phenotype gets more than the sum of the parts of contributing genes
Measurement of epistasis between genes allows characterisation of functional genetic interaction networks
What is synthetic lethality?
An epistatic phenomenon in which pairs of individually nonessential genes interact to cause double mutant inviability
What is an additive interaction?
1 - (1st growth reduction x 2nd growth reduction) = total growth reduction
What is an aggravating interaction?
Negatively epistatic
The double mutant fitness is lower than the additive expected which implies separate but compensatory pathways
What is an alleviating interaction?
Positively epistatic
Fitness is greater than expected but the interaction is in the same pathway or complex
What does synthetic lethality reveal?
Functional redundancy
Occurs in compensating pathways producing some essential protein or complementing components of a complex process
What is synthetic genetic array?
A method to construct non-essential deletion mutant pairs
Describe the process of SGA
Mating and diploid selection in histidine auxotrophs
When grown in medium containing histidine, diploids survive, haploids killed
Sporulate diploids by replicating onto plates with minimal nutrients
Two mating types
Select haploids by growing in Histidine minus medium
Double mutant haploids selected in presence of kan and nat (select for query and dma gene mutants)