Reverse Genetics

Question 1

To analyse a genes function we need to:

Answer 1

Disrupt or inactivate it. This could be done through inactivation by RNAi, mutations, or by depleting the gene product.

Question 2

Genetic Redundancy

Answer 2

When 2 genes have the same function. Both need to be disrupted in order to see a phenotype. These genes are often related to each other.

Question 3

Homolog

Answer 3

Genes that are related to each other by descent from a common ancestral gene.

Question 4

Paralog

Answer 4

Genes that are related by duplication within a genome. They may evolve new functions. Descended from a common ancestor.

Question 5

Ortholog

Answer 5

Genes in different species that evolved from a common ancestral gene by speciation.

Question 6

Methods of Reverse Genetics

Answer 6

1. Recombination (e.g. via CRISPR-Cas9)
2. RNAi
3. Rapid depletion of proteins (e.g. Auxin induced degradation by ubiquitinylation)
4. Protein inactivation by drugs (e.g. Aspirin, inhibits cyclooxygenase enzymes)

Question 7

Limitations of Reverse Genetics

Answer 7

1. May not be an obvious phenotype to observe
2. Phenotype may lead to embryonic fatality
3. May be 2 genes for one function
4. Phenotype may produce multiple effects from a single gene (pleiotropic)