FIG. 4.

Rheological models of undifferentiated and differentiated chromatin. (a) G′ and G″ measured for undifferentiated chromatin (blue markers) and fitted to the Maxwell fluid model (blue lines). Inset shows tan(δ) = G″/G′, dashed line represents ω⁻¹. (b) Diagram of the Maxwell fluid as a spring-dashpot system. (c) G′ and G″ measured for differentiated chromatin (magenta markers) and fitted to the Burgers model (magenta lines). Inset shows tan(δ) = G″/G′, dashed line indicates ω⁻¹. (d) Diagram of the Burgers model as a spring-dashpot system. (e) Cartoon illustrating the fluid-like (blue) state of undifferentiated chromatin and the emergence of local solid-like phase (magenta) upon differentiation. Error bars show standard error.