Squishy Physics

Next seminar: Wednesday December 11th 2019 in Pierce Hall 209 at 6:00 PM

From single-cell growth to population growth.

 

Jie Lin

Harvard University

 

 

Abstract: Genetically identical cells often display diversity in phenotypes such as gene expression levels and doubling times. In the first part of my talk, I will discuss whether cell-to-cell variability can confer benefits to the entire population by enhancing its fitness, especially in the presence of exponential growth of cell volume. I will present a model in which the sources of variability are stochastic cell division. Notably, the variability can be either beneficial or detrimental depending on its correlation across lineages, suggesting that the fitness advantage of variability is sensitive to the intrinsic dynamics of cell growth. Then I will discuss the effects of cell volume on stochastic gene expression. Many experiments have shown that mRNA and protein copy numbers at the single-cell level are often proportional to the cell volume in growing cells. Current models based on the assumption that genes and mRNAs are limiting for gene expression are incompatible with these observations. I will present a minimal gene expression model to capture the homeostasis of protein and mRNA concentrations in growing cells. Notably, the model predicts that the exponential growth of cell volume can be violated as the cell volume exceeds a threshold, which has recently been experimentally observed.

 

 

Squishy Physics & Pizza Seminar Series

When: Wednesday Evenings - Pizza served at 5:55 PM, talks start at 6 pm till...

Where: Room 209, Pierce Hall, 29 Oxford St, on the Harvard Campus. Directions and parking instructions are here.

What: These talks are informal, with emphasis on new results and ideas, rather than polished presentations. The Squishy audience members typically include soft matter scientists, physicists, engineers, chemists, and biologists.  The goal is to stimulate discussion with the audience.  Talks are typically about 45 minutes long, with lots of questions along the way.

Pizza: Only the finest! 

How to join the weekly Squishy Physics mailing list: please visit the Signup Page.

 

Parking: Metered parking is available on Oxford Street.  Speakers, please contact Matthew Zahnzinger to obtain a parking permit.  

Squishy Physics is sponsored by the Cabot Corporation, Dean Cherry Murray and the Weitz Research Group.

If you have comments or suggestions or would like to give a talk, please contact Stefano Aime or Perry Ellis.

Here is the upcoming schedule