Gene mapping

Question 1

How to make a mapping cross

Answer 1

1. cross the two parental types
2. Cross the hybrid offspring with each other
3. Recombination takes place during meiosis, shuffling the parental genomes around

Question 2

How to genotype a mapping cross

Answer 2

Place molecular markers at regular places across the genome

Question 3

How to determine where the causative gene is

Answer 3

Perform a statistical test at regular intervals along each chromosome to test for an association with the trait

Question 4

What does QTL stand for

Answer 4

Quantitative trait locus

Question 5

What does a peak mean

Answer 5

That its likely to be a location of QTL

Question 6

Case study 1: Mice

Answer 6

Oldfeild mice have longer entrance tunnels than deer mice, their adaptation is to avoid predators
- Swapping the M allele for P allele means longer tunnels

Question 7

What does the genome wide association study (QWAS) involve

Answer 7

• Uses random sample from a population
  -Relies on ancestral recombination events
  -Requires a higher marker density

Question 8

What do Manhattan plots involve

Answer 8

Each dot represents a SNP marker
Skyscrapers are regions with genes that explain variation
Horizontal line is the genome wide significance threshold

Question 9

Case study 2: genetics of human height

Answer 9

-Human height is heritble but even the biggest studies cannot find most of the genes
- Biggest chromosomes have the most genes affecting height

Question 10

Case study 3: Horns in a Soay shape

Answer 10

Scurs are caused by a single gene on chromosome 10