11.4 Genetic effects on gene expression
Why does expression for the same gene vary across individuals?
There are many factors that can contribute to variability in gene expression in a population:
- Environment (ex: diet, climate, disease)
- Stochasticity/noise
- Epigenetics (methylation, repressive/activating histone marks)
- Genetics (genetic variants in promoter, enhancer, etc. sequences)
How do we discover genetic variants that influence gene expression?
We can perform a genome-wide association study, similar to what we would do for an organismal phenotype like height. This time, our phenotype is the expression of a specific gene, and we can search for genetic variants that impact this expression.