Genetic Memory in Mice
What kind of information is passed down through our DNA?
Hypotheses
I predict that the mice will become cautious of identifiable features (such as smell or vision) that have been associated with danger. The mice will then breed offspring who will hopefully show similar behavior towards the same dangers although they have neverexperianced them, just as their parents would. If all goes well, this cycle will continue on through generations.
Materials
•10 mice; 5 of the male sex and 5 of the female sex
•Cherry blossom odorent
•Closed habitat for mice (to enclose smell)
•Electric shock material
Procedure
I will train mice to fear the smell of cherry blossom using electric shocks in an enclosed environment, before allowing them to breed. I will then assess whether their offspring show similar fear of the smell. I will continue this for three generations of mice. It is important.
•Independant variable: the mice
•Dependant variable: the reaction produced by the mice and their offspring
•Controlled variables: Cherry blossom odorant, electric shocks
Data
•Generation 1; shows fear for smell of cherry blossom; with electric shock training
•Generation 2; shows fear for smell of cherry blossom; without traumatic or stressful
experiences in lifetime.
•Generation 3; shows fear for smell of cherry blossom; without traumatic or stressful experiences in lifetime.
Conclusion
The data I collected was sufficient in drawing a conclusion. The first generation of mice developped a distinct fear of the smell of cherry blossom. The offspring produced also showed fearful responses to the odour of cherry blossom compared to a neutral odour, despite never having encountered them before. The following generation also showed the same behaviour. This effect continued even if the mice had been fathered through artificial insemination. I found the brains of the trained mice and their offspring showed structural changes in areas used to detect the odour. The DNA of the animals also carried chemical changes, known as epigenetic methylation, on the gene responsible for detecting the odour. This suggests that experiences are somehow transferred from the brain into the genome, allowing them to be passed on to later generations. Some genetic memory was inherited, proving my hypothesis.
Evaluation
Overall, the experiment went well. The mice responded well and reacted to the environment which I controlled. I definitely recommend trying this with different smells and visuals, (i.e. instead of cherry blossom smell, the colour red). This increase the amount of data and help us to better understand whether the reaction works varies between different forms of fear and sense.