Seminar ”Coupled Oscillators and Chaos in Gene Regulation” by Mogens H. Jensen

• Date: Wednesday, October 31
• Time: 16:00-17:00
• Venue: B503, Center Building
• Speaker: Mogens H. Jensen, Niels Bohr Institute, University of Copenhagen

Coupled Oscillators and Chaos in Gene Regulation

Mogens H. Jensen,
Niels Bohr Institute,
University of Copenhagen, Denmark   

Oscillating patterns with periods of 2-5 hours have been observed for transcription factors in single cells. The oscillations appear as a response to DNA damage and other induced stresses. We have identified the central feed-back loops leading to oscillations and formulated genetic networks in terms of mathematical equations. By applying an external periodic protein signal, it is possible to lock the internal oscillation of a transcription factor to the external signal [1]. We have observed that the two signals lock when the ration between the two frequencies is close to basic rational numbers [1] which can be mapped out as Arnold tongues.  When the tongues start to overlap we may observe mode hopping and chaotic dynamics in the concentration of proteins [1]. We investigate how this influences gene productions through stochastic simulations by Gillespie algorithm. In the chaotic regime, genes with high affinity decreases their production with increased external amplitude, while genes with low affinity increases their production [2].

[1] M.L. Heltberg, R. Kellogg, S. Krishna, S. Tay and M.H. Jensen,
"Noise-induced NF-kB Mode Hopping Enables Temporal Gene Multiplexing"
Cell Systems 3, p. 532–539 (2017).
[2] M.L. Heltberg, S. Krishna and M.H. Jensen, "Chaotic Dynamics in
Transcription Factors: Enhancement of Low Affinity Genes, Efficient
Protein Complex Formation and Generation of Population Heterogeneity",
Nature Communication (2018).