Professor Rosemary Braun
Molecular Biosciences
Northwestern University
Evanston, IL
Webinar link below or attend in-person @ Beckman Institute - Room 3269

Monday, December 13, 2021
3:00 pm (CT)

Abstract

The circadian rhythm orchestrates a vast array of behavioral and physiological processes on an approximate 24-hour period, enabling nearly all organisms -- from bread mold to fruit-flies to humans -- to anticipate and adapt to the Earth's day. Entrainable by environmental conditions, the rhythm itself is generated by a self-sustained molecular oscillator present in nearly every cell; this in turn governs the expression of thousands of genes, precisely coordinating biomolecular functions at the microscopic scale. At the macroscopic scale, the clock has been shown to impact an organism's metabolism and lifespan, and abundant epidemiological evidence has linked circadian disruption with increased disease risk. Yet the mechanisms by which the clock affects health and adaptation are still unclear. High-throughput omics assays enable us to probe these processes in molecular detail, with the goal of making inferences about which genes are under circadian control and how their dynamics change under different conditions. However, analyzing transcriptomic time-series data also raises a new challenge: that of characterizing dynamics when the data are noisy, sparsely sampled in time, and may not be strictly periodic. In this talk, I will discuss our recent work on nonparametric, model-free methods to analyze circadian transcriptomic data by exploiting results from dynamical systems theory, nonlinear dimension reduction, and topological data analysis.