evoLunch: Isabella Tomanek

[Christelle Fraisse]

Dear evoLunchers,

​I am very happy to announce our next speaker,

Isabella Tomanek

(IST Austria)

Gene amplification tunes expression to fluctuating environments

Wednesday, February 8th, 2017

at 12:30, IST AUSTRIA, Cafeteria (building 22), 1st floor

Bella is a PhD student at IST, jointly shared by John Bollback and Calin Guet. She is working on the evolution of gene expression in bacterial populations.

Abstract
To thrive in ever-changing environments bacteria need to regulate gene expression. While cis-regulatory sequences evolve too slowly to respond to environmental fluctuations, gene amplifications increase expression on short time scales. Given their intrinsic instability, we asked whether amplifications could be beneficial in fluctuating environments where gene dosage needs to increase and decrease along with conditions. Making use of the dual selection marker galK we devised a system for monitoring copy number and expression of an amplified gene under fluctuating selection. We found that galK copy number and associated expression tightly follow alternating selection pressures. Despite resembling true gene regulation, this “regulation through amplification” (RTA) arises solely from selection acting on an expression polymorphism created by instable amplifications. As such, RTA could represent a universal, yet previously unappreciated, mechanism allowing bacterial populations to rapidly tune gene expression to selective requirements.


Speakers 2016/2017: click here

​Christelle​.