Speaker
Mogens Hogh Jensen
(Niels Bohr Institute)
Description
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 forming Arnold tongues[1]. When the tongues start
to overlap we may observe mode hopping and chaotic dynamics
in the concentration of proteins [1,2]. We investigate how
this influences gene productions through stochastic
simulations. 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, "On chaotic
dynamics in transcription factors and the associated
effects in differential gene regulation", Nature
Communication, DOI 10.1038/s41467-018-07932-1 (2019).