Introduction

Question 1

What is genetic analysis?

Answer 1

Analysis of the relationship between genotype and phenotype

Question 2

What is a phenotype?

Answer 2

The observable characteristic that results from interactions between genotype and the environment

Question 3

What is a genotype?

Answer 3

The genetic constitution of an organism

Question 4

What are the 3 ways to determine a phenotype?

Answer 4

Look at it, biochemical analysis, behavioural assay

Question 5

What are 5 properties that genetic analysis looks at?

Answer 5

Inheritance - how is the gene passed down to the next generation
Location - where is the gene in the genome
Expression - when and where is the gene expressed
Function - what does it do
Interactions - does it interact with other genes
Mutation - what happens without the gene

Question 6

How do you do genetic analysis?

Answer 6

Manipulate genes, analyze the phenotypes, draw conclusions from the relationships

Question 7

What is forward genetics?

Answer 7

Starting with a mutant phenotype and finding the gene that causes that phenotype

Question 8

How do you use a forward genetics approach?

Answer 8

1. Decide what you want to look at and in what organism
2. Generate mutants
3. Screen for or select the mutants with the desired phenotype
4. Map and clone the responsible gene
5. Determine the molecular function of the isolated gene

Question 9

What are the pros of a forward genetics approach?

Answer 9

Time tested and used successfully many times before, no prior knowledge of the system is required, works well for easily distinguishable phenotypes, can generate stable mutant lines

Question 10

What are the cons of a forward genetics approach?

Answer 10

Tedious for phenotypes that can’t be easily distinguished, only looking at one trait, can miss genes in multi-gene families

Question 11

What is a reverse genetics approach?

Answer 11

Starting with a gene and finding the phenotype

Question 12

How do you do a reverse genetics approach?

Answer 12

1. Decide what gene you want to look at
2. Mutate the sequence
3. Introduce the sequence into the host
4. Screen the transformants for mutants
5. Analyze the phenotype of the mutants

Question 13

What are the pros of a reverse genetics approach?

Answer 13

Targeted, can apply high throughput methods, will often know the molecular function of a gene already so easier to find the phenotype

Question 14

What are the cons of a reverse genetics approach?

Answer 14

Need the gene sequence, might not have null mutations, requires transformation methods, may have off target effects