Lecture 18 - Genetics In Sport

Question 1

What is the normal process involving angiotensin converting enzyme (ACE)?

Answer 1

Liver
Angiotensinogen > cleaved by renin 
Angiotensin I > cleaved by ACE
Angiotensin II 
Degrades bradykinin (vasodilator) and is vasoconstrictor

Question 2

How can ACE influence performance in long distance runners?

Short distance swimmers?

Answer 2

Insertion > lower levels of ACE > increase frequency in distance runners = endurance. This is because it lowers Ang II, increases bradykinin and leads to better vasodilation and substrate metabolism

Deletions > higher levels of ACE > increase frequency in short distance swimmers = strength. This is because it causes muscle hypertrophy due to more Ang II which increases factors for muscle growth

Question 3

What makes insulin growth factor 1?
What stimulates production?
What does it do?

Answer 3

Liver
Growth hormone
Acts through IGF-1 receptor to activate pathways associated with proliferation, growth, protein synthesis, metabolism and survival

Question 4

List the pathway of IGF-1 starting with exercise

Answer 4

1) Exercise is stimuli for pituitary gland
2) Stimulates growth hormone
3) Stimulates Liver which stimulates IGF-1 through nutrition and insulin inputs
4) IGF-1 causes tissue growth/remodelling (dependent on intensity/duration) which leads to:
a) Protein synthesis/hypertrophy
b) Neurotrophic effects; exercise induced neurogenesis to link body fitness with brain fitness

Question 5

IGF-1 * are associated with * responses to * training

Exercise causes gene * changes that underlie * and * adaptations via * hormones

Answer 5

Polymorphisms; positive; stress

Expression; structural; metabolic; growth

Question 6

What is epigenetics and how can it be done?

Answer 6

Genetic control by factors other than an individual’s DNA sequence

DNA methylation (addition of methyl group to cytosine to block transcription machinery and inactivate gene)
Histone modifications (methylation/acetylation)
RNA-associated silencing

Question 7

DNA methylation is ** and there is evidence that the environment can * it by exercise

• of genes involved in * such as PGC-1 were * post exercise, because exercise caused an * in the mRNA coding for it

Answer 7

Mitotically stable; regulate

Methylation; metabolism; reduced; increase

Question 8

What does PGC-1 do?

Answer 8

Regulates genes involved in energy metabolism, mitochondria biogenesis and function
Regulates fibre type determination

Question 9

VO2 max is largely * but can be increased by *

The genes to predict VO2 trainability were identified and associated with what 5 things?

Answer 9

Genetic; training

Oxygen delivery
Lipid metabolism
Electrolytes balance
Muscular subsystems 
Oxidative phosphorylation and energy production