Complementation in yeast - Experiment 3

Question 1

Why can’t we preform complementation tests with E. coli?

Answer 1

E. coli are exclusively haploid, an organism needs to be able to create diploid offspring to complement

Question 2

What is the purpose of a complementation test?

Answer 2

To determine if a mutation is in the same gene or different genes when two mutant strains have the same mutant phenotype

Question 3

What are allelic mutations? Do they complement?

Answer 3

Mutations in the same gene. They don’t complement

Question 4

What are non-allelic mutations? Do they complement?

Answer 4

Mutations in different genes. They do complement

Question 5

Why do mutations need to be non-allelic to complement?

Answer 5

Each parent can supply a functional wild-type gene to the offspring. A parent with mutant gene 1 and wild type gene 2 can pass the WT gene 2 to the diploid offspring. The other parent with WT gene 1 and mutant gene 2 can pass the WT gene 1 to the offspring. The offspring then has two WT genes

Question 6

What medium do we preform a complementation test on? What do we see if the strains complement?

Answer 6

Minimal media. If the strains complement, there will be growth with a wild type phenotype

Question 7

What characteristic does the mutant gene need to have in order for complementation to occur?

Answer 7

It needs to be recessive. If the mutation is dominant to wild-type, we will see the mutant phenotype even if complementation occurred

Question 8

What mutations are grouped together in a complementation group?

Answer 8

Allelic

Question 9

How is a biosynthetic pathway analysis different from a complementation test?

Answer 9

A biosynthetic pathway analysis tells us where the strain is blocked, a complementation test tells us if they have a mutation in the same gene