The Evolution of Gene Expression | Thomas Lenormand || Radcliffe Institute

TL;DR

This talk explores the evolution of gene regulation and its relationship with diploidy and regulatory complexity in eukaryotes.

Transcript

• Thanks a lot for this very nice introduction as usual. And I'm impressed by the level you already put in that. So you've been explaining quite a few things already. That's excellent. And so I'm thankful for everybody at Radcliffe, all the staff, everybody there. It's really a wonderful place to have years to rest and change our minds. It has been... Read More

Key Insights

• ❓ Diploidy can evolve due to the masking and purging effects of deleterious mutations, even though it reduces the average fitness of the population.
• 🥺 Stronger cis-regulators are favored because they increase the exposure of genes to selection, leading to the evolution of regulatory complexity.

Questions & Answers

Q: What is the main difference between haploidy and diploidy?

Haploidy refers to having a single copy of each gene, while diploidy refers to having two copies. Diploidy allows for masking of deleterious mutations and provides a better chance for purging them from the population.

Q: How does the dominance of deleterious mutations affect the evolution of diploidy?

Deleterious mutations are often partially recessive, meaning their effects are not as severe in diploid individuals. This allows for the accumulation of masking mutations, leading to the evolution of diploidy.

Q: What is the role of cis-regulation in the evolution of gene expression?

Cis-regulators, such as enhancers, control the expression of genes by attracting transcription factors. Mutations in these cis-regulatory regions can lead to allele-specific expression and changes in the dominance of deleterious mutations, driving the evolution of regulatory complexity.

Q: How does the evolution of stronger cis-regulators affect gene expression?

The evolution of stronger cis-regulators increases the expression of specific alleles, leading to changes in the dominance of deleterious mutations. This can result in higher fitness if the mutation is less deleterious or lower fitness if the mutation is more deleterious.

Summary & Key Takeaways

• The speaker is at Radcliffe to work on gene regulation and gene expression, focusing on the topic of why eukaryotic gene regulation is so complex compared to prokaryotes.

• The talk introduces the concepts of haploidy and diploidy, and the effects of deleterious mutations on fitness.

• The speaker presents a model that shows how diploidy can evolve due to the masking and purging effects of deleterious mutations, leading to the evolution of complex regulatory systems.