1: Gene expression evolution

Question 1

What is Cis-regulatory variation?

Answer 1

DNA that regulates transcription that is in close proximity to the gene it regulates

Question 2

Describe enhancer sequences and their role

Answer 2

Sequences close to the gene they regulate (but do not have to be directly upstream like the core promoters)
- Help bind transcription factors

Question 3

What’s the point of alternative splicing?

Answer 3

• Way for gene to code for multiple proteins by post-transcriptional regulation joining exons in different combos
• Instead of changing expression level it changes how the exons are spliced together

Question 4

What is Trans-regulatory variation?

Answer 4

DNA that regulates transcription that is far away from the gene it regulates
e.g transcription factors, RNA

Question 5

What are Pleiotropic effects?

Answer 5

multiple effects of one mutation

Question 6

Briefly describe the debate about: how important is (trans/cis) regulatory variation compared to coding gene changes?

Answer 6

• Some argue that, complex traits are influenced more by changes in gene expression than changes in protein struc
• Some argue that regulatory variation = greater evolutionary flexivility (as peliotropic effects are often purged from the pop.)
• Argument against this: Gene duplication events

= Overall, both have evidence but we don’t know yet which is most important