Gene Environment Interaction Flashcards
What was Galton’s assumption about nature/nurture?
Believed everything was controlled by genetics; a gene for crime, gene for intelligence
What well-known genetic mutation is commonly seen in obese lab mice?
Leptin protein
What does the Leptin protein do?
Informs fullness, when to stop eating
What is some behavioural evidence for the role of genetics in obesity?
Identical twin studies, when asked to eat as much as they feel will will tend to put on and lose weight together
How does FTO gene affect obesity?
Changes appetite by making food more attractive, compulsive eating similar to drug addiction
What FTO mutation is responsible for behavioural changes?
Changes in two base pair, AA (normal) changed to TT (increased appetite)
What is some statistical evidence for environmental effects on obesity?
Food much cheaper, less healthy, and obesity more of an issue among lower classes (who cannot afford healthy food)
What is some experimental evidence for environmental effects on obesity?
Starved mice are still thin no matter their genetics
How is gene expression in alligators famously controlled by environment?
Temperature-dependent sex determination
What is an example of temperature-dependent gene expression in drosophila?
Eye color mutation, white eyes develop in high temperatures and dark brown eyes at low temperatures
How are temperature-sensitive mutations used to study development?
1/5 new mutations are viable at 20 degrees, lethal at 30; changing temperature for short periods of development can show when certain genes are activated
How do arctic hares make their fur white in preparation for winter?
Less light during shorter days leads to black pigment genes being switched off
How to trees know when to drop their leaves?
Light-sensitive expression of death-gene in leaves, switched on when days go shorter
How is light-sensitive gene expression possibly useful for humans?
Possible influence on seasonal affective depression
What mutation prevents E. coli from growing in tryptophan-free environments?
Tryp-minus, prevents them from being able to synthesise their own tryptophan
What is phenylketonuria?
Mutation in humans that causes loss of ability to metabolise phenylalanine
What are the effects of phenylketonuria?
PhA present in nearly all food, so inability to metabolise causes unhealthy eventually fatal buildup of PhA
How can phenylketonuria be detected?
Guthrie test, uses a PhA-minus bacteria to test blood for buildup of PhA
How can phenylketonuria be controlled environmentally?
PhA-free diet
What is the pathology of porphyria?
Inability to break down red pigment in blood, cannot do out in the day, can go mad
What environmental change triggered porphyria-like disease in south africa?
Introduction of barbituate drugs
Why can 10% of the population feel no analgesia from codeine?
Lack gene that metabolises codeine into morphine
What mutation was responsible for the discovery that certain women experiences a 35x increased risk of thromboembolism following use of a contraceptive pill?
Factor V Leiden, carries base 6-fold increased risk, jumps to 35-fold when paired with certain contraceptive pill
How is Huntington’s Disease affected by environment?
Only expresses at a certain age
