1. Suppose you start a firm where you genotype individuals (i.e. determine which alleles they carry for a set of genes) and help them with their training for marathon. The following figure shows the genes involved in the process and how they are related:
Basically you are genotyping for 4 genes:
CB: Carb breaker. Breaks down carbs to glucose which the cells can use
GT: Glucose transporter. Takes the glucose to muscles.
EG: Energy Generator. Converts glucose and oxygen to energy to run. Unfortunately also creates waste. If waste accumulates, EG stops working.
WR: Waste Remover. Removes the waste.
Based on this information answer the following questions:
- Your first client is homozygous for a mutation in GT gene (GT'/GT'), which decreases its activity significantly. What is the consequence for your client's running career?
- A second client walks in. He has a homozygous mutation in CB gene (CB'/CB'), which again decreases activity. What will happen?
- How would you describe the epistatic relationship between CB and GT? Can you help either client overcome their problem and run a successful marathon?
- Your third client is heterozygous for a dominant mutation in his WR gene (WR'/WR), which allows him to remove waste quicker. What is the consequence of this mutation? What is the form of the epistatic interaction between GT and WR?