Stochasticity and reproducibility in intracellular cell transmission

SILVINA PONCE DAWSON

Seminario; Coloquios del Center for Nonlinear Studies, Los Alamos National Laboratory; 2017

Living systems are continuously exchanging information with their environment. This exchange occurs at all levels from single cells to complex organisms. Information transmission in cells usually involves changes in the concentration of substances that are sensed by receptors located on the plasma membrane. The binding of these substances triggers a sequence of intracellular changes that eventually lead to an end response. The binding process is highly stochastic. Cells, however, are able to generate quite reproducible end responses. How do they manage to do this? In this talk I will discuss two examples. In the first one, related to the development of the antero-posterior axis in Drosophila melanogaster embryos, it is through space and time averaging that individual binding sites on DNA can ?read? the local bulk concentration of transcription factors with relatively high accuracy. In the second example, which is characterized by the occurrence of sequences of calcium pulses that are due to the release of calcium from intracellular stores, it is by controlling the accumulated cytosolic calcium that cells can change the irregularity in the sequence of inter-spike time intervals.