Block C Workshop - Yeast Genetics

Question 1

What is S. cerevisiae used as a model for?

Answer 1

To study aging, the cell cycle, apoptosis, gene expression and metabolism
(Slide 3)

Question 2

What are the biotechnological uses of yeast and fungi?

Answer 2

Fermentations, productions of biopharmaceuticals, biocatalysts and recombinant proteins
(Slide 5)

Question 3

What is the doubling time of S. cerevisiae?

Answer 3

~ 90 mins
(Slide 6)

Question 4

What 2 conformations can the 4 haploid spores in a tetrad be arranged in?

Answer 4

Ordered or Unordered
(Slide 8)

Question 5

What are the 3 different types of gene segregation which can occur in a tetrad?

Answer 5

Parental ditype (PD)
Nonparental ditype (NPD)
Tetratype (T)
(Slide 9)

Question 6

What is the parental ditype (PD) of gene segregation in a tetrad?

Answer 6

Two pairs of spores, with each pair containing the same genotype of one of the 2 parental spores
(Slide 9)

Question 7

What is the nonparental ditype (NPD) of segregation in a tetrad?

Answer 7

Two pairs of spores, with each pair differing from both the parental spores and each other
(Slide 9)

Question 8

What is the Tetratype (T) of segregation in a tetrad?

Answer 8

4 unique spores, each containing a different combination of alleles resulting from genetic recombination between the 2 parental chromosomes
(Slide 9)

Question 9

What does it mean if the ratio of parental ditype (PD) is higher than the ratio of nonparental ditype (NPD) gene segregation in tetrads?

Answer 9

That the observed genetic loci are linked
(Slide 11)

Question 10

What does it mean if the ratio of parental ditype (PD), nonparental ditypes (NPD) and tetratype (T) is 1:1:4?

Answer 10

It indicates independent assortment and therefore there is no linkage between the observed genetic loci
(Slide 11)

Question 11

If genes are linked, what is the formula to estimate map distance (D) in centiMorgans (cM)?

Answer 11

D = 100(6NPD + T) / 2(PD + T + NPD)
(Slide 12)

Question 12

What can homologous recombination be used for?

Answer 12

To knock-out or knock-in
(Slide 18)

Question 13

What are CRISPR-Cas technologies used for?

Answer 13

Gene editing
(Slide 18)

Question 14

What are the 2 proteins of interest in a yeast two-hybrid experiment called?

Answer 14

“Bait” and “Prey” proteins
(Slide 19)

Question 15

What are the “bait” and “prey” proteins fused to in a yeast two-hybrid experiment?

Answer 15

GAL4 domains
(Slide 19)

Question 16

What does the interaction between the “bait” and “prey” proteins in a yeast two-hybrid experiment lead to?

Answer 16

Their interactions lead to the GAL4 domains being in close proximity of each other, leading to the reporter gene being transcribed
(Slide 19)

Question 17

What is a common caveat of the yeast two-hybrid experiment?

Answer 17

Many false-positives and false-negatives
(Slide 19)

Question 18

What are 2 examples of variations of the yeast two-hybrid experiments and what is the difference?

Answer 18

One-hybrid and three-hybrid variations, which involve different arrangements of the “bait” and “prey” proteins
(Slide 19)

Question 19

What are protein localisation studies used to study?

Answer 19

Protein function
(Slide 22)

Question 20

What are genes fused to in protein localisation studies?

Answer 20

Green fluorescent protein (gfp) or another fluorescent reporter gene
(Slide 22)

Question 21

What can be used to mark a gene other than a fluorescent reporter gene in protein localisation study?

Answer 21

Immunofluorescence
(Slide 22)

Question 22

What 2 things to do with the reporter gene in protein localisation study?

Answer 22

The position of the tag (whether it’s the N or C- terminals) and so is the choice of reporter gene
(Slide 22)

Question 23

How can co-localisation be studied in a protein localisation study?

Answer 23

Using different fluorescent reporters
(Slide 22)

Question 24

What can random or targeted mutagenesis lead to?

Answer 24

The development of new isolates that demonstrate the improved productivity and / or growth
(Slide 23)

Question 25

How can we design genetic engineering strategies for optimising production yields?

Answer 25

By understanding yeast metabolism and bio-synthetic pathways of specific products
(Slide 23)